diff --git a/.gitignore b/.gitignore
index 9957e5e..980a9f6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 *.DS_Store
 obj/
 .vscode/c_cpp_properties.json
+.vscode/settings.json
diff --git a/Makefile b/Makefile
index a9d25f7..0817360 100644
--- a/Makefile
+++ b/Makefile
@@ -5,12 +5,12 @@ LD=$(PREFIX)-ld
 OBJCOPY=$(PREFIX)-objcopy
 OBJDUMP=$(PREFIX)-objdump
 
-all: bin/ROMBUS.bin obj/rombus.s obj/driver.s obj/driver_abs.sym
+all: bin/ROMBUS_8M.bin obj/rombus.s obj/driver.s obj/driver_abs.sym
 
 obj:
-	mkdir $@
+	mkdir -p $@
 bin:
-	mkdir $@
+	mkdir -p $@
 
 
 obj/entry.o: entry.s obj
@@ -20,14 +20,38 @@ obj/entry_rel.sym: obj obj/entry.o
 	$(OBJDUMP) -t obj/entry.o > $@
 
 
+obj/spi.o: spi.c obj
+	$(CC) -Wall -march=68020 -c -Os $< -o $@
+obj/spi_hal.o: spi_hal.s spi_hal_common.s obj
+	$(AS) $< -o $@
+obj/spi_rx8.o: spi_rx8.s spi_hal.s spi_hal_common.s obj
+	$(AS) $< -o $@
+obj/spi_rx16.o: spi_rx16.s spi_hal.s spi_hal_common.s obj
+	$(AS) $< -o $@
+obj/spi_tx8.o: spi_tx8.s spi_hal.s spi_hal_common.s obj
+	$(AS) $< -o $@
+obj/spi_tx16.o: spi_tx16.s spi_hal.s spi_hal_common.s obj
+	$(AS) $< -o $@
+obj/spi_rxtx8.o: spi_rxtx8.s spi_hal.s spi_hal_common.s obj
+	$(AS) $< -o $@
+obj/spi_delay.o: spi_delay.s obj
+	$(AS) $< -o $@
+
+
 obj/rombus.o: rombus.c obj
-	$(CC) -Wall -march=68030 -c -Os $< -o $@
+	$(CC) -Wall -march=68020 -c -Os $< -o $@
 
 obj/rombus.s: obj obj/rombus.o
 	$(OBJDUMP) -d obj/rombus.o > $@
 
-obj/driver.o: obj obj/entry.o obj/rombus.o
-	$(LD) -Ttext=40851D70 -o $@ obj/entry.o obj/rombus.o
+obj/driver.o: obj obj/entry.o obj/rombus.o obj/spi.o obj/spi_hal.o \
+			  obj/spi_rx8.o obj/spi_rx16.o \
+			  obj/spi_tx8.o obj/spi_tx16.o \
+			  obj/spi_rxtx8.o
+	$(LD) -Ttext=40851D70 -o $@ obj/entry.o obj/rombus.o obj/spi.o obj/spi_hal.o \
+								obj/spi_rx8.o obj/spi_rx16.o \
+								obj/spi_tx8.o obj/spi_tx16.o \
+								obj/spi_rxtx8.o
 
 obj/driver.s: obj obj/driver.o
 	$(OBJDUMP) -d obj/driver.o > $@
@@ -35,11 +59,11 @@ obj/driver.s: obj obj/driver.o
 obj/driver_abs.sym: obj obj/driver.o
 	$(OBJDUMP) -t obj/driver.o > $@
 
-
 bin/driver.bin: bin obj/driver.o
 	$(OBJCOPY) -O binary obj/driver.o $@
 
-bin/baserom_romdisk_ramtest.bin: bin roms/baserom.bin bin/driver.bin obj/driver_abs.sym obj/entry_rel.sym 
+
+bin/baserom_rombus_ramtest.bin: bin roms/baserom.bin bin/driver.bin obj/driver_abs.sym obj/entry_rel.sym 
 	cp roms/baserom.bin $@ # Copy base rom
 	# Patch driver
 	dd if=bin/driver.bin of=$@ bs=1 seek=335248 skip=32 conv=notrunc # Copy driver code
@@ -51,23 +75,19 @@ bin/baserom_romdisk_ramtest.bin: bin roms/baserom.bin bin/driver.bin obj/driver_
 	cat obj/entry_rel.sym | grep "[0-9]\s*DStatus" | cut -c5-8 | xxd -r -p - | dd of=$@ bs=1 seek=335230 count=2 conv=notrunc
 	cat obj/entry_rel.sym | grep "[0-9]\s*DClose" | cut -c5-8 | xxd -r -p - | dd of=$@ bs=1 seek=335232 count=2 conv=notrunc
 
-bin/baserom_romdisk_noramtest.bin: bin bin/baserom_romdisk_ramtest.bin
-	cp bin/baserom_romdisk_ramtest.bin $@ # Copy base rom
+bin/baserom_rombus_noramtest.bin: bin bin/baserom_rombus_ramtest.bin
+	cp bin/baserom_rombus_ramtest.bin $@ # Copy base rom
 	# Disable RAM test
 	printf '\x4E\xD6' | dd of=$@ bs=1 seek=288736 count=2 conv=notrunc
 	printf '\x4E\xD6' | dd of=$@ bs=1 seek=289016 count=2 conv=notrunc
 
 
-bin/ROMBUS.bin: bin bin/baserom_romdisk_noramtest.bin disks/RDisk7M5.dsk
+bin/ROMBUS_8M.bin: bin bin/baserom_rombus_noramtest.bin disks/RDisk.dsk
 	# Copy base rom with ROM disk driver
-	cp bin/baserom_romdisk_noramtest.bin $@
-	# Patch ROM disk driver parameter table
-	printf '\x00\x01\x2A\x29' | dd of=$@ bs=1 seek=335260 count=4 conv=notrunc # Patch CDR patch offset
-	printf '\x40\x89\x2A\x14' | dd of=$@ bs=1 seek=335268 count=4 conv=notrunc # Patch CDR name address
-	printf '\x44' | dd of=$@ bs=1 seek=335273 count=1 conv=notrunc # Patch CDR disable byte
+	cp bin/baserom_rombus_noramtest.bin $@
 	printf '\x00\x78\x00\x00' | dd of=$@ bs=1 seek=335276 count=4 conv=notrunc # Patch ROM disk size
 	# Copy ROM disk image
-	dd if=disks/RDisk7M5.dsk of=$@ bs=1024 seek=512 conv=notrunc
+	dd if=disks/RDisk.dsk of=$@ bs=1024 seek=512 conv=notrunc
 
 .PHONY: clean
 clean:
diff --git a/bin/ROMBUS.bin b/bin/ROMBUS_8M.bin
similarity index 97%
rename from bin/ROMBUS.bin
rename to bin/ROMBUS_8M.bin
index a9d9bf1..b9bb521 100755
Binary files a/bin/ROMBUS.bin and b/bin/ROMBUS_8M.bin differ
diff --git a/bin/baserom_romdisk_noramtest.bin b/bin/baserom_rombus_noramtest.bin
similarity index 53%
rename from bin/baserom_romdisk_noramtest.bin
rename to bin/baserom_rombus_noramtest.bin
index 3fd33e5..64b557a 100755
Binary files a/bin/baserom_romdisk_noramtest.bin and b/bin/baserom_rombus_noramtest.bin differ
diff --git a/bin/baserom_romdisk_ramtest.bin b/bin/baserom_rombus_ramtest.bin
similarity index 53%
rename from bin/baserom_romdisk_ramtest.bin
rename to bin/baserom_rombus_ramtest.bin
index 8eaa96d..75bcdf1 100755
Binary files a/bin/baserom_romdisk_ramtest.bin and b/bin/baserom_rombus_ramtest.bin differ
diff --git a/bin/driver.bin b/bin/driver.bin
index 2aacf1b..5669579 100755
Binary files a/bin/driver.bin and b/bin/driver.bin differ
diff --git a/disks/RDisk7M5.dsk b/disks/RDisk.dsk
similarity index 100%
rename from disks/RDisk7M5.dsk
rename to disks/RDisk.dsk
diff --git a/entry.s b/entry.s
index 7c124e7..9a95417 100644
--- a/entry.s
+++ b/entry.s
@@ -8,13 +8,27 @@
 dc.l	0x00000000, 0x00000000, 0x00000000, 0x00000000
 dc.l	0x00000000, 0x00000000, 0x00000000, 0x00000000
 
-SDiskSig:
-.ascii	"\5SDisk\0"
+RDiskSig:
+.ascii	"\5RDisk\0"
+.align 4
+RDiskDBGDisPos:
+dc.l 0x00000031
+RDiskCDRDisPos:
+dc.l 0xFFFFFFFF
+RDiskDBGNameAddr:
+dc.l 0x4088002A
+RDiskCDRNameAddr:
+dc.l 0x00000000
+RDiskDBGDisByte:
+dc.b 0x44
+RDiskCDRDisByte:
+dc.b 0x44
+RDiskRAMRequired:
+.ascii	"16"
+
 .align 4
 RDiskSize:
 dc.l 0x00780000
-SDiskSize:
-dc.l 0x80000000
 
 DOpen:
 	movem.l		%A0-%A1, -(%SP)
diff --git a/old/Makefile b/old/Makefile
deleted file mode 100644
index b5f5fcd..0000000
--- a/old/Makefile
+++ /dev/null
@@ -1,89 +0,0 @@
-# path to RETRO68
-RETRO68=~/Retro68-build/toolchain
-
-PREFIX=$(RETRO68)/bin/m68k-apple-macos
-AS=$(PREFIX)-as
-CC=$(PREFIX)-gcc
-LD=$(PREFIX)-ld
-OBJCOPY=$(PREFIX)-objcopy
-OBJDUMP=$(PREFIX)-objdump
-CFLAGS=-march=68030 -c -Os
-
-all: bin/rom16M_swap.bin obj/rdisk7M5.s obj/driver7M5.s obj/entry_rel.sym obj/driver_abs.sym
-
-obj:
-	mkdir obj
-
-bin:
-	mkdir bin
-
-
-obj/entry.o: entry.s obj
-	$(AS) $< -o $@
-
-obj/entry_rel.sym: obj obj/entry.o
-	$(OBJDUMP) -t obj/entry.o > $@
-
-
-obj/rdisk7M5.o: rdisk.c obj
-	$(CC) -Wall -DRDiskSize=7864320 $(CFLAGS) $< -o $@
-
-obj/rdisk7M5.s: obj obj/rdisk7M5.o
-	$(OBJDUMP) -d obj/rdisk7M5.o > $@
-
-
-obj/spi.o: spi.c obj
-	$(CC) -Wall $(CFLAGS) $< -o $@
-
-obj/spi.s: obj obj/spi.o
-	$(OBJDUMP) -d obj/spi.o > $@
-
-
-obj/sdmmc.o: sdmmc.c obj
-	$(CC) -Wall $(CFLAGS) -Os $< -o $@
-
-obj/sdmmc.s: obj obj/sdmmc.o
-	$(OBJDUMP) -d obj/sdmmc.o > $@
-
-
-
-obj/driver7M5.o: obj obj/entry.o obj/rdisk7M5.o
-	$(LD) -Ttext=40851D70 -o $@ obj/entry.o obj/rdisk7M5.o obj/spi.o obj/sdmmc.o
-
-obj/driver7M5.s: obj obj/driver7M5.o
-	$(OBJDUMP) -d obj/driver7M5.o > $@
-
-obj/driver_abs.sym: obj obj/driver7M5.o
-	$(OBJDUMP) -t obj/driver7M5.o > $@
-
-
-bin/driver7M5.bin: bin obj/driver7M5.o
-	$(OBJCOPY) -O binary obj/driver7M5.o $@
-
-bin/rom8M.bin: bin baserom.bin RDisk7M5.dsk bin bin/driver7M5.bin obj/driver_abs.sym obj/entry_rel.sym 
-	cp baserom.bin $@ # Copy base rom
-	# Patch driver
-	dd if=bin/driver7M5.bin of=$@ bs=1 seek=335248 skip=32 conv=notrunc # Copy driver code
-	printf '\x78' | dd of=$@ bs=1 seek=335168 count=1 conv=notrunc # Set resource flags
-	printf '\x4F' | dd of=$@ bs=1 seek=335216 count=1 conv=notrunc # Set driver flags
-	cat obj/entry_rel.sym | grep "DOpen" | cut -c5-8 | xxd -r -p - | dd of=$@ bs=1 seek=335224 count=2 conv=notrunc
-	cat obj/entry_rel.sym | grep "DPrime" | cut -c5-8 | xxd -r -p - | dd of=$@ bs=1 seek=335226 count=2 conv=notrunc
-	cat obj/entry_rel.sym | grep "DControl" | cut -c5-8 | xxd -r -p - | dd of=$@ bs=1 seek=335228 count=2 conv=notrunc
-	cat obj/entry_rel.sym | grep "DStatus" | cut -c5-8 | xxd -r -p - | dd of=$@ bs=1 seek=335230 count=2 conv=notrunc
-	cat obj/entry_rel.sym | grep "DClose" | cut -c5-8 | xxd -r -p - | dd of=$@ bs=1 seek=335232 count=2 conv=notrunc
-	dd if=RDisk7M5.dsk of=$@ bs=1024 seek=512 count=7680 conv=notrunc # copy disk image
-
-bin/rom8M_swap.bin: bin bin/rom8M.bin
-	dd if=bin/rom8M.bin of=$@ conv=swab # swap bytes
-
-bin/iisi_swap.bin: bin iisi.bin
-	dd if=iisi.bin of=$@ conv=swab # swap bytes
-
-bin/rom16M_swap.bin: bin/iisi_swap.bin bin/rom8M_swap.bin
-	cat bin/rom8M_swap.bin > $@
-	cat bin/iisi_swap.bin >> $@
-
-
-.PHONY: clean
-clean:
-	rm -fr bin obj
diff --git a/old/baserom.bin b/old/baserom.bin
deleted file mode 100755
index 12c1e51..0000000
Binary files a/old/baserom.bin and /dev/null differ
diff --git a/old/entry.s b/old/entry.s
deleted file mode 100644
index ea864cf..0000000
--- a/old/entry.s
+++ /dev/null
@@ -1,84 +0,0 @@
-.EQU	killCode,	 1
-.EQU	noQueueBit,	 9
-.EQU	kioTrap,	 6
-.EQU	kioResult,	16
-.EQU	kcsCode,	26
-.EQU	JIODone,	0x08FC
-.GLOBAL RDiskSig
-.GLOBAL RDiskDBGNamePos
-.GLOBAL RDiskDBGDisPos
-.GLOBAL RDiskDBGDisByte
-.GLOBAL RDiskCDRNamePos
-.GLOBAL RDiskCDRDisPos
-.GLOBAL RDiskCDRDisByte
-
-dc.l	0x00000000, 0x00000000, 0x00000000, 0x00000000
-dc.l	0x00000000, 0x00000000, 0x00000000, 0x00000000
-
-RDiskSig:
-.ascii	"\5RDisk\0"
-.align 4
-RDiskDBGDisPos:
-dc.l 0x00000031
-RDiskCDRDisPos:
-dc.l 0x00012CAF
-RDiskDBGNameAddr:
-dc.l 0x4088002A
-RDiskCDRNameAddr:
-dc.l 0x40892C96
-RDiskDBGDisByte:
-dc.b 0x44
-RDiskCDRDisByte:
-dc.b 0x44
-RDiskRAMRequired:
-.ascii	"16"
-
-.align 4
-DOpen:
-	movem.l		%A0-%A1, -(%SP)
-	bsr			RDOpen
-	movem.l		(%SP)+, %A0-%A1
-	rts
-
-DClose:
-	movem.l		%A0-%A1, -(%SP)
-	bsr			RDClose
-	movem.l		(%SP)+, %A0-%A1
-	rts
-
-DPrime:
-	movem.l		%A0-%A1, -(%SP)
-	bsr			RDPrime
-	movem.l		(%SP)+, %A0-%A1
-	bra.b		IOReturn
-
-DControl:
-	movem.l		%A0-%A1, -(%SP)
-	bsr			RDCtl
-	movem.l		(%SP)+, %A0-%A1
-	cmpi.w		#killCode, kcsCode(%A0)
-	bne.b		IOReturn
-	rts
-
-DStatus:
-	movem.l		%A0-%A1, -(%SP)
-	bsr			RDStat
-	movem.l		(%SP)+, %A0-%A1
-
-IOReturn:
-	move.w		kioTrap(%A0), %D1
-	btst		#noQueueBit, %D1
-	beq.b		Queued
-
-NotQueued:
-	tst.w		%D0
-	ble.b		ImmedRTS
-	clr.w		%D0
-
-ImmedRTS:
-	move.w		%D0, kioResult(%A0)
-	rts
-
-Queued:
-	move.l		JIODone, -(%SP)
-	rts
diff --git a/old/rombus.c b/old/rombus.c
deleted file mode 100644
index 7a295ab..0000000
--- a/old/rombus.c
+++ /dev/null
@@ -1,361 +0,0 @@
-#include <Memory.h>
-#include <Devices.h>
-#include <Files.h>
-#include <Disks.h>
-#include <Errors.h>
-#include <Events.h>
-#include <OSUtils.h>
-
-#include "rdisk.h"
-
-// Decode keyboard/PRAM settings
-static void RDDecodeSettings(Ptr recoveryEN, Ptr unmountEN, Ptr mountEN) {
-	// Read PRAM
-	char legacy_startup;
-	RBReadXPRAM(1, 4, &legacy_startup);
-
-	// Decode settings: boot from recovery, unmount (don't boot), mount (after boot)
-	if (RBIsRPressed()) { // R boots from ROM recovery
-		*recoveryEN = 1; // Enable recovery partition
-		*unmountEN = 0; // Unmount SD so we don't boot from it
-		*mountEN = 1; // Mount SD later
-	} else {
-		*recoveryEN = 0; // Disable recovery partition
-		if (legacy_startup & 0x10) { // Boot from SD disk
-			*unmountEN = 0; // Don't unmount so we boot from this drive
-			*mountEN = 0; // No need to mount later since we are boot disk
-		} else if (legacy_startup & 0x20) { // Mount SD disk under other boot volume
-			*unmountEN = 1; // Unmount to not boot from our disk
-			*mountEN = 1; // Mount in accRun
-		} else {
-			*unmountEN = 1; // Unmount
-			*mountEN = 0; // Don't mount again
-		}
-	}
-}
-
-// Switch to 32-bit mode and copy
-#pragma parameter C24(__A0, __A1, __D0)
-void __attribute__ ((noinline)) C24(Ptr sourcePtr, Ptr destPtr, unsigned long byteCount) {
-	signed char mode = true32b;
-	SwapMMUMode(&mode);
-	BlockMove(sourcePtr, destPtr, byteCount);
-	SwapMMUMode(&mode);
-}
-
-// Switch to 32-bit mode and get
-#pragma parameter __D0 G24(__A2)
-char __attribute__ ((noinline)) G24(Ptr pos) {
-	long ret;
-	signed char mode = true32b;
-	SwapMMUMode(&mode);
-	ret = *pos; // Peek
-	SwapMMUMode(&mode);
-	return ret;
-}
-
-// Switch to 32-bit mode and set
-#pragma parameter S24(__A2, __D3)
-void __attribute__ ((noinline)) S24(Ptr pos, char patch) {
-	signed char mode = true32b;
-	SwapMMUMode(&mode);
-	*pos = patch; // Poke
-	SwapMMUMode(&mode);
-}
-
-// Figure out the first available drive number >= 5
-static int RBFindDrvNum() {
-	DrvQElPtr dq;
-	int drvNum = 5;
-	for (dq = (DrvQElPtr)(GetDrvQHdr())->qHead; dq; dq = (DrvQElPtr)dq->qLink) {
-		if (dq->dQDrive >= drvNum) { drvNum = dq->dQDrive + 1; }
-	}
-	return drvNum;
-}
-
-static void RBOpenRDisk(RDiskStorage_t *c) {
-	int drvNum;
-	
-	// Find first available drive number for ROM recovery
-	drvNum = RBFindDrvNum();
-
-	// Set ROM recovery drive status
-	//c->rStatus.track = 0;
-	c->rStatus.writeProt = -1; // nonzero is write protected
-	c->rStatus.diskInPlace = 8; // 8 is nonejectable disk
-	c->rStatus.installed = 1; // drive installed
-	//c->rStatus.sides = 0;
-	//c->rStatus.qType = 1;
-	c->rStatus.dQDrive = drvNum;
-	//c->rStatus.dQFSID = 0;
-	c->rStatus.dQRefNum = d->dCtlRefNum;
-	c->rStatus.driveSize = RDiskSize / 512;
-	//c->rStatus.driveS1 = (RDiskSize / 512) >> 16;
-
-	// Decompress icon
-	#ifdef RDISK_COMPRESS_ICON_ENABLE
-	char *src = &RDiskIconCompressed[0];
-	char *dst = &c->rIcon[0];
-	UnpackBits(&src, &dst, RDISK_ICON_SIZE);
-	#endif
-
-	// Add RDisk to drive queue and return
-	RDiskAddDrive(c->rStatus.dQRefNum, drvNum, (DrvQElPtr)&c->rStatus.qLink);
-}
-
-static void RBOpenSDisk(RDiskStorage_t *c) {
-	int drvNum;
-	
-	// Find first available drive number for SD disk
-	drvNum = RBFindDrvNum();
-
-	// Set SD disk drive status
-	//c->rStatus.track = 0;
-	c->rStatus.writeProt = 0; // 0 is writable
-	c->rStatus.diskInPlace = 8; // 8 is nonejectable disk
-	c->rStatus.installed = 1; // drive installed
-	//c->rStatus.sides = 0;
-	c->rStatus.qType = 1;
-	c->rStatus.dQDrive = drvNum;
-	//c->rStatus.dQFSID = 0;
-	c->rStatus.dQRefNum = d->dCtlRefNum;
-	c->rStatus.driveSize = SDiskSize / 512;
-	c->rStatus.driveS1 = (SDiskSize / 512) >> 16;
-
-	// Decompress icon
-	#ifdef SDISK_COMPRESS_ICON_ENABLE
-	char *src = &SDiskIconCompressed[0];
-	char *dst = &c->sIcon[0];
-	UnpackBits(&src, &dst, SDISK_ICON_SIZE);
-	#endif
-
-	// Add SDisk to drive queue and return
-	RDiskAddDrive(c->rstatus.dQRefNum, drvNum, (DrvQElPtr)&c->sStatus.qLink);
-}
-
-#pragma parameter __D0 RBOpen(__A0, __A1)
-OSErr RBOpen(IOParamPtr p, DCtlPtr d) {
-	RDiskStorage_t *c;
-	char legacy_startup;
-
-	// Do nothing if already opened
-	if (d->dCtlStorage) { return noErr; }
-
-	// Do nothing if inhibited
-	RBReadXPRAM(1, 4, &legacy_startup);
-	if (legacy_startup & 0x40) { return noErr; } 
-
-	// Allocate storage struct
-	d->dCtlStorage = NewHandleSysClear(sizeof(RDiskStorage_t));
-	if (!d->dCtlStorage) { return openErr; }
-
-	// Lock our storage struct and get master pointer
-	HLock(d->dCtlStorage);
-	c = *(RDiskStorage_t**)d->dCtlStorage;
-
-	// Create RDisk and SDisk entries in drive queue, then return
-	RBOpenRDisk(c);
-	RBOpenSDisk(c);
-	return noErr;
-}
-
-// Init is called at beginning of first prime (read/write) call
-static void RBInit(IOParamPtr p, DCtlPtr d, RDiskStorage_t *c) {
-	char recoveryEN, unmountEN, mountEN;
-	// Mark init done
-	c->initialized = 1;
-	// Decode settings
-	RDDecodeSettings(&recoveryEN, &unmountEN, &mountEN);
-
-	// Unmount if not booting from ROM disk
-	if (!recoveryEN) { c->rStatus.diskInPlace = 0; }
-
-	// Unmount if not booting from ROM disk
-	if (unmountEN) { c->SStatus.diskInPlace = 0; }
-
-	// If mount enabled, enable accRun to post disk inserted event later
-	if (mountEN) { 
-		d->dCtlDelay = 150; // Set accRun delay (150 ticks is 2.5 sec.)
-		d->dCtlFlags |= dNeedTimeMask; // Enable accRun
-	}
-}
-
-static OSErr RDPrime(IOParamPtr p, DCtlPtr d) {
-	// Get pointer to correct position in ROM disk buffer
-	Ptr disk = RDiskBuf + d->dCtlPosition;
-
-	// Return disk offline error if virtual disk not inserted
-	if (!c->rStatus.diskInPlace) { return offLinErr; }
-
-	//  Bounds checking
-	if (d->dCtlPosition >= RDiskSize || p->ioReqCount >= RDiskSize || 
-		d->dCtlPosition + p->ioReqCount >= RDiskSize) { return paramErr; }
-
-	// Service read or write request
-	cmd = p->ioTrap & 0x00FF;
-	if (cmd == aRdCmd) {
-		if (*MMU32bit) { BlockMove(disk, p->ioBuffer, p->ioReqCount); }
-		else { copy24(disk, StripAddress(p->ioBuffer), p->ioReqCount); }
-	} else if (cmd == aWrCmd) { return wPrErr;
-	} else { return noErr; } //FIXME: Fail if cmd isn't read or write?
-
-	// Update count and position/offset, then return
-	d->dCtlPosition += p->ioReqCount;
-	p->ioActCount = p->ioReqCount;
-	return noErr;
-}
-
-static OSErr SDPrime(IOParamPtr p, DCtlPtr d) {
-	
-}
-
-#pragma parameter __D0 RBPrime(__A0, __A1)
-OSErr RBPrime(IOParamPtr p, DCtlPtr d) {
-	RDiskStorage_t *c;
-	char cmd;
-
-	// Return disk offline error if dCtlStorage null
-	if (!d->dCtlStorage) { return notOpenErr; }
-	// Dereference dCtlStorage to get pointer to our context
-	c = *(RDiskStorage_t**)d->dCtlStorage;
-
-	// Initialize if this is the first prime call
-	if (!c->initialized) { RBInit(p, d, c); }
-
-	if (p->ioVRefNum == c->sStatus.dQDrive) {
-		return SDPrime(p, d, c);
-	} else if (p->ioVRefNum == c->rStatus.dQDrive) {
-		return RDPrime(p, d, c);
-	} else { return nsvErr; }
-}
-
-static OSErr RDCtl(CntrlParamPtr p, DCtlPtr d, RDiskStorage_t *c) {
-	// Handle control request based on csCode
-	switch (p->csCode) {
-		case kFormat: return controlErr;
-		case kVerify:
-			if (!c->rStatus.diskInPlace) { return controlErr; }
-			return noErr;
-		case kEject:
-			// "Reinsert" disk if ejected illegally
-			if (c->rStatus.diskInPlace) { 
-				PostEvent(diskEvt, c->status.dQDrive);
-			}
-			return controlErr; // Eject not allowed so return error
-		case kDriveIcon: case kMediaIcon: // Get icon
-			#ifdef RDISK_COMPRESS_ICON_ENABLE
-			*(Ptr*)p->csParam = (Ptr)c->rIcon;
-			#else
-			*(Ptr*)p->csParam = (Ptr)RDiskIcon;
-			#endif
-			return noErr;
-		case kDriveInfo:
-			//  high word (bytes 2 & 3) clear
-			//  byte 1 = primary + fixed media + internal
-			//  byte 0 = drive type (0x11 is ROM disk)
-			*(long*)p->csParam = 0x00000411;
-			return noErr;
-		case 24: // Return SCSI partition size
-			*(long*)p->csParam = RDiskSize / 512;
-			return noErr;
-		default: return controlErr;
-	}
-}
-
-static OSErr SDCtl(CntrlParamPtr p, DCtlPtr d, RDiskStorage_t *c) {
-	// Handle control request based on csCode
-	switch (p->csCode) {
-		case kFormat:
-			// FIXME: implement SD format
-			return controlErr;
-		case kVerify:
-			// FIXME: implement SD verify
-			return noErr;
-		case kEject:
-			// "Reinsert" disk if ejected illegally
-			if (c->sStatus.diskInPlace) { 
-				PostEvent(diskEvt, c->sStatus.dQDrive);
-			}
-			return controlErr; // Eject not allowed so return error
-		case kDriveIcon: case kMediaIcon: // Get icon
-			#ifdef SDISK_COMPRESS_ICON_ENABLE
-			*(Ptr*)p->csParam = (Ptr)c->sIcon;
-			#else
-			*(Ptr*)p->csParam = (Ptr)SDiskIcon;
-			#endif
-			return noErr;
-		case kDriveInfo:
-			//  high word (bytes 2 & 3) clear
-			//  byte 1 = primary + fixed media + internal
-			//  byte 0 = drive type (0x01 is unspecified drive)
-			*(long*)p->csParam = 0x00000401;
-			return noErr;
-		case 24: // Return SCSI partition size
-			*(long*)p->csParam = SDiskSize / 512;
-			return noErr;
-		default: return controlErr;
-	}
-}
-
-#pragma parameter __D0 RBCtl(__A0, __A1)
-OSErr RBCtl(CntrlParamPtr p, DCtlPtr d) {
-	RDiskStorage_t *c;
-	// Fail if dCtlStorage null
-	if (!d->dCtlStorage) { return notOpenErr; }
-	// Dereference dCtlStorage to get pointer to our context
-	c = *(RDiskStorage_t**)d->dCtlStorage;
-	// Handle control request based on csCode
-	switch (p->csCode) {
-		case killCode:
-			return noErr;
-		case accRun:
-			d->dCtlFlags &= ~dNeedTimeMask; // Disable accRun
-			c->sStatus.diskInPlace = 8; // 8 is nonejectable disk
-			PostEvent(diskEvt, c->sStatus.dQDrive); // Post disk inserted event
-			return noErr;
-		case 2351: // Post-boot
-			c->initialized = 1; // Skip initialization
-			d->dCtlDelay = 30; // Set accRun delay (30 ticks is 0.5 sec.)
-			d->dCtlFlags |= dNeedTimeMask; // Enable accRun
-			return noErr;
-	}
-
-	// Otherwise, dispatch to correct drive
-	if (p->ioVRefNum == c->sStatus.dQDrive) {
-		return SDCtl(p, d, c);
-	} else if (p->ioVRefNum == c->rStatus.dQDrive) {
-		return RDCtl(p, d, c);
-	} else { return nsvErr; }
-}
-
-#pragma parameter __D0 RBStat(__A0, __A1)
-OSErr RBStat(CntrlParamPtr p, DCtlPtr d) {
-	RDiskStorage_t *c;
-	// Fail if dCtlStorage null
-	if (!d->dCtlStorage) { return notOpenErr; }
-	// Dereference dCtlStorage to get pointer to our context
-	c = *(RDiskStorage_t**)d->dCtlStorage;
-	// Handle status request based on csCode
-	switch (p->csCode) {
-		case kDriveStatus:
-			// Otherwise, copy correct drive status
-			if (p->ioVRefNum == c->sStatus.dQDrive) {
-				BlockMove(&c->sStatus, &p->csParam, sizeof(DrvSts2));
-			} else if (p->ioVRefNum == c->rStatus.dQDrive) {
-				BlockMove(&c->rStatus, &p->csParam, sizeof(DrvSts2));
-			} else { return nsvErr; }
-			return noErr;
-		default: return statusErr;
-	}
-}
-
-#pragma parameter __D0 RBClose(__A0, __A1)
-OSErr RBClose(IOParamPtr p, DCtlPtr d) {
-	// If dCtlStorage not null, dispose of it
-	if (!d->dCtlStorage) { return noErr; }
-	//RDiskStorage_t *c = *(RDiskStorage_t**)d->dCtlStorage;
-	HUnlock(d->dCtlStorage);
-	DisposeHandle(d->dCtlStorage);
-	d->dCtlStorage = NULL;
-	return noErr;
-}
diff --git a/old/rombus.h b/old/rombus.h
deleted file mode 100644
index 0e02990..0000000
--- a/old/rombus.h
+++ /dev/null
@@ -1,179 +0,0 @@
-#ifndef ROMBUS_H
-#define ROMBUS_H
-
-#define RDiskBuf ((char*)0x408C0000)
-#define SDiskSize (0x80000000L)
-#define BufPtr ((Ptr*)0x10C)
-#define MemTop ((Ptr*)0x108)
-#define MMU32bit ((char*)0xCB2)
-
-#pragma parameter __D0 RBReadXPRAM(__D0, __D1, __A0)
-OSErr RBReadXPRAM(short numBytes, short whichByte, Ptr dest) = {0x4840, 0x3001, 0xA051};
-
-#pragma parameter __D0 RBAddDrive(__D1, __D0, __A0)
-OSErr RBAddDrive(short drvrRefNum, short drvNum, DrvQElPtr dq) = {0x4840, 0x3001, 0xA04E};
-
-static inline char RBIsRPressed() { return *((char*)0x175) & 0x80; }
-
-typedef struct RBStorage_s {
-	DrvSts2 sStatus;
-	DrvSts2 rStatus;
-	char initialized;
-} RBStorage_t;
-
-typedef void (*RDiskCopy_t)(Ptr, Ptr, unsigned long);
-#define copy24(s, d, b) { RDiskCopy_t f = C24; f(s, d, b); }
-
-typedef char (*RDiskPeek_t)(Ptr);
-#define peek24(a, d) { RDiskPeek_t f = G24; d = f(a); }
-
-typedef void (*RDiskPoke_t)(Ptr, char);
-#define poke24(a, d) { RDiskPoke_t f = S24; f(a, d); }
-
-#define RDISK_ICON_SIZE (285)
-const char RDiskIcon[RDISK_ICON_SIZE] = {
-	// Icon
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b10000000, 0b00000000, 0b00000000, 0b00000001,
-	0b10001111, 0b00011110, 0b00111100, 0b01111001,
-	0b10001001, 0b00010010, 0b00100100, 0b01001001,
-	0b10001001, 0b00010010, 0b00100100, 0b01001001,
-	0b10001001, 0b00010010, 0b00100100, 0b01001001,
-	0b10001111, 0b00011110, 0b00111100, 0b01111001,
-	0b11000000, 0b00000000, 0b00000000, 0b00000001,
-	0b01010101, 0b01010101, 0b11010101, 0b01010101,
-	0b01111111, 0b11111111, 0b01111111, 0b11111111,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	// Mask
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b01111111, 0b11111111, 0b11111111, 0b11111111,
-	0b01111111, 0b11111111, 0b11111111, 0b11111111,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	27, 'G', 'a', 'r', 'r', 'e', 't', 't', '\'', 's', ' ', 
-	'W', 'o', 'r', 'k', 's', 'h', 'o', 'p', ' ', 
-	'R', 'O', 'M', ' ', 'D', 'i', 's', 'k', 0
-};
-
-#define SDISK_ICON_SIZE (283)
-const char const SDiskIcon[SDISK_ICON_SIZE] = {
-	// Icon
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b00000000, 0b00000000, 0b00010000,
-	0b00000001, 0b00000001, 0b10000000, 0b11010000,
-	0b00000001, 0b01101101, 0b10110110, 0b11010000,
-	0b00000001, 0b01101101, 0b10110110, 0b11010000,
-	0b00000001, 0b01101101, 0b10110110, 0b11010000,
-	0b00000001, 0b01101101, 0b10110110, 0b11010000,
-	0b00000001, 0b01101101, 0b10110110, 0b11010000,
-	0b00000001, 0b00000000, 0b00000000, 0b00010000,
-	0b00000001, 0b00000000, 0b00000000, 0b00010000,
-	0b00000010, 0b00000000, 0b00000000, 0b00010000,
-	0b00000100, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001110, 0b00000000, 0b00000000, 0b00010000,
-	0b00000010, 0b00000000, 0b00000000, 0b00010000,
-	0b00000010, 0b00000000, 0b00000000, 0b00010000,
-	0b00000010, 0b00000000, 0b00000000, 0b00010000,
-	0b00000100, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001000, 0b00000000, 0b00000000, 0b00010000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	// Mask
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000001, 0b11111111, 0b11111111, 0b11110000,
-	0b00000011, 0b11111111, 0b11111111, 0b11110000,
-	0b00000111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00000011, 0b11111111, 0b11111111, 0b11110000,
-	0b00000011, 0b11111111, 0b11111111, 0b11110000,
-	0b00000011, 0b11111111, 0b11111111, 0b11110000,
-	0b00000111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00001111, 0b11111111, 0b11111111, 0b11110000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	25, 'G', 'a', 'r', 'r', 'e', 't', 't', '\'', 's', ' ', 
-	'W', 'o', 'r', 'k', 's', 'h', 'o', 'p', ' ', 
-	'R', 'O', 'M', 'B', 'U', 'S', 0
-};
-
-#endif
\ No newline at end of file
diff --git a/old/sdmmc.c b/old/sdmmc.c
deleted file mode 100644
index 048f678..0000000
--- a/old/sdmmc.c
+++ /dev/null
@@ -1,220 +0,0 @@
-#include "sdmmc.h"
-
-
-/*--------------------------------------------------------------------------
-
-   Module Private Functions
-
----------------------------------------------------------------------------*/
-
-#define	INIT_PORT()	init_port()	/* Initialize MMC control port (CS/CLK/DI:output, DO:input) */
-#define DLY_US(n)	dly_us(n)	/* Delay n microseconds */
-#define	FORWARD(d)	forward(d)	/* Data in-time processing function (depends on the project) */
-
-/* Definitions for MMC/SDC command */
-#define CMD0	(0x40+0)	/* GO_IDLE_STATE */
-#define CMD1	(0x40+1)	/* SEND_OP_COND (MMC) */
-#define	ACMD41	(0xC0+41)	/* SEND_OP_COND (SDC) */
-#define CMD8	(0x40+8)	/* SEND_IF_COND */
-#define CMD16	(0x40+16)	/* SET_BLOCKLEN */
-#define CMD17	(0x40+17)	/* READ_SINGLE_BLOCK */
-#define CMD24	(0x40+24)	/* WRITE_BLOCK */
-#define CMD55	(0x40+55)	/* APP_CMD */
-#define CMD58	(0x40+58)	/* READ_OCR */
-
-/* Card type flags (CardType) */
-#define CT_MMC				0x01	/* MMC ver 3 */
-#define CT_SD1				0x02	/* SD ver 1 */
-#define CT_SD2				0x04	/* SD ver 2 */
-#define CT_SDC				(CT_SD1|CT_SD2)	/* SD */
-#define CT_BLOCK			0x08	/* Block addressing */
-
-
-
-static char CardType;			/* 0:MMC, 1:SDv1, 2:SDv2, 3:Block addressing */
-
-
-/*-----------------------------------------------------------------------*/
-/* Send a command packet to MMC                                          */
-/*-----------------------------------------------------------------------*/
-static char send_cmd(char cmd, long arg)
-{
-	char n, res;
-
-	if (cmd & 0x80) {	/* ACMD<n> is the command sequense of CMD55-CMD<n> */
-		cmd &= 0x7F;
-		res = send_cmd(CMD55, 0);
-		if (res > 1) return res;
-	}
-
-	/* Select the card */
-	CS_H(); spi_rx();
-	CS_L(); spi_rx();
-
-	/* Send a command packet */
-	spi_tx(cmd);					/* Start + Command index */
-	s((BYTE)(arg >> 24));	/* Argument[31..24] */
-	spi_tx((BYTE)(arg >> 16));	/* Argument[23..16] */
-	spi_tx((BYTE)(arg >> 8));		/* Argument[15..8] */
-	spi_tx((BYTE)arg);			/* Argument[7..0] */
-	n = 0x01;						/* Dummy CRC + Stop */
-	if (cmd == CMD0) n = 0x95;		/* Valid CRC for CMD0(0) */
-	if (cmd == CMD8) n = 0x87;		/* Valid CRC for CMD8(0x1AA) */
-	spi_tx(n);
-
-	/* Receive a command response */
-	n = 10;								/* Wait for a valid response in timeout of 10 attempts */
-	do {
-		res = spi_rx();
-	} while ((res & 0x80) && --n);
-
-	return res;			/* Return with the response value */
-}
-
-
-
-/*--------------------------------------------------------------------------
-
-   Public Functions
-
----------------------------------------------------------------------------*/
-
-
-/*-----------------------------------------------------------------------*/
-/* Initialize Disk Drive                                                 */
-/*-----------------------------------------------------------------------*/
-sdstatus_t sdmmc_init()
-{
-	char n, cmd, ty, buf[4];
-	uint tmr;
-
-	CS_H();
-	spi_skip(10);			/* Dummy clocks */
-
-	ty = 0;
-	if (send_cmd(CMD0, 0) == 1) {			/* Enter Idle state */
-		if (send_cmd(CMD8, 0x1AA) == 1) {	/* SDv2 */
-			for (n = 0; n < 4; n++) buf[n] = spi_rx();	/* Get trailing return value of R7 resp */
-			if (buf[2] == 0x01 && buf[3] == 0xAA) {			/* The card can work at vdd range of 2.7-3.6V */
-				for (tmr = 1000; tmr; tmr--) {				/* Wait for leaving idle state (ACMD41 with HCS bit) */
-					if (send_cmd(ACMD41, 1UL << 30) == 0) break;
-					DLY_US(1000);
-				}
-				if (tmr && send_cmd(CMD58, 0) == 0) {		/* Check CCS bit in the OCR */
-					for (n = 0; n < 4; n++) buf[n] = spi_rx();
-					ty = (buf[0] & 0x40) ? CT_SD2 | CT_BLOCK : CT_SD2;	/* SDv2 (HC or SC) */
-				}
-			}
-		} else {							/* SDv1 or MMCv3 */
-			if (send_cmd(ACMD41, 0) <= 1) 	{
-				ty = CT_SD1; cmd = ACMD41;	/* SDv1 */
-			} else {
-				ty = CT_MMC; cmd = CMD1;	/* MMCv3 */
-			}
-			for (tmr = 1000; tmr; tmr--) {			/* Wait for leaving idle state */
-				if (send_cmd(cmd, 0) == 0) break;
-				DLY_US(1000);
-			}
-			if (!tmr || send_cmd(CMD16, 512) != 0)			/* Set R/W block length to 512 */
-				ty = 0;
-		}
-	}
-	CardType = ty;
-	release_spi();
-
-	return ty ? 0 : STA_NOINIT;
-}
-
-
-/*-----------------------------------------------------------------------*/
-/* Read partial sector                                                   */
-/*-----------------------------------------------------------------------*/
-sdresult_t sdmmc_readp(Ptr buf, long sector, uint offset, uint count)
-{
-	DRESULT res;
-	char d;
-	uint bc, tmr;
-
-
-	if (!(CardType & CT_BLOCK)) sector *= 512;	/* Convert to byte address if needed */
-
-	res = RES_ERROR;
-	if (send_cmd(CMD17, sector) == 0) {		/* READ_SINGLE_BLOCK */
-
-		tmr = 1000;
-		do {							/* Wait for data packet in timeout of 100ms */
-			DLY_US(100);
-			d = spi_rx();
-		} while (d == 0xFF && --tmr);
-
-		if (d == 0xFE) {				/* A data packet arrived */
-			bc = 514 - offset - count;
-
-			/* Skip leading bytes */
-			if (offset) spi_skip(offset);
-
-			/* Receive a part of the sector */
-			if (buff) {	/* Store data to the memory */
-				do
-					*buff++ = spi_rx();
-				while (--count);
-			} else {	/* Forward data to the outgoing stream */
-				do {
-					d = spi_rx();
-					FORWARD(d);
-				} while (--count);
-			}
-
-			/* Skip trailing bytes and CRC */
-			spi_skip(bc);
-
-			res = RES_OK;
-		}
-	}
-
-	release_spi();
-
-	return res;
-}
-
-
-/*-----------------------------------------------------------------------*/
-/* Write partial sector                                                  */
-/*-----------------------------------------------------------------------*/
-sdresult_t sdmmc_writep(const Ptr buf, long sc)
-{
-	DRESULT res;
-	UINT bc, tmr;
-	static UINT wc;
-
-	res = RES_ERROR;
-
-	if (buff) {		/* Send data bytes */
-		bc = (UINT)sc;
-		while (bc && wc) {		/* Send data bytes to the card */
-			spi_tx(*buff++);
-			wc--; bc--;
-		}
-		res = RES_OK;
-	} else {
-		if (sc) {	/* Initiate sector write transaction */
-			if (!(CardType & CT_BLOCK)) sc *= 512;	/* Convert to byte address if needed */
-			if (send_cmd(CMD24, sc) == 0) {			/* WRITE_SINGLE_BLOCK */
-				spi_tx(0xFF); spi_tx(0xFE);		/* Data block header */
-				wc = 512;							/* Set byte counter */
-				res = RES_OK;
-			}
-		} else {	/* Finalize sector write transaction */
-			bc = wc + 2;
-			while (bc--) spi_tx(0);	/* Fill left bytes and CRC with zeros */
-			if ((spi_rx() & 0x1F) == 0x05) {	/* Receive data resp and wait for end of write process in timeout of 300ms */
-				for (tmr = 10000; spi_rx() != 0xFF && tmr; tmr--)	/* Wait for ready (max 1000ms) */
-					DLY_US(100);
-				if (tmr) res = RES_OK;
-			}
-			release_spi();
-		}
-	}
-
-	return res;
-}
diff --git a/old/sdmmc.h b/old/sdmmc.h
deleted file mode 100644
index e2a49b6..0000000
--- a/old/sdmmc.h
+++ /dev/null
@@ -1,29 +0,0 @@
-#ifndef SDMMC_H
-#define SDMMC_H
-
-
-/* Status of Disk Functions */
-typedef char sdstatus_t;
-
-#define STA_NOINIT		0x01	/* Drive not initialized */
-#define STA_NODISK		0x02	/* No medium in the drive */
-
-
-/* Results of Disk Functions */
-typedef enum sdmmc_result_e {
-	RES_OK = 0,		/* 0: Function succeeded */
-	RES_ERROR,		/* 1: Disk error */
-	RES_NOTRDY,		/* 2: Not ready */
-	RES_PARERR		/* 3: Invalid parameter */
-} sdresult_t;
-
-
-/*---------------------------------------*/
-/* Prototypes for disk control functions */
-/*---------------------------------------*/
-sdstatus_t sdmmc_init();
-sdresult_t sdmmc_readp(Ptr buf, long sector, uint offset, uint count);
-sdresult_t sdmmc_writep(const Ptr buf, long sc);
-
-
-#endif
diff --git a/old/spi.c b/old/spi.c
deleted file mode 100644
index 4b918ff..0000000
--- a/old/spi.c
+++ /dev/null
@@ -1,164 +0,0 @@
-#include "spi.h"
-
-/*-------------------------------------------------------------------------*/
-/* Platform dependent macros and functions needed to be modified           */
-/*-------------------------------------------------------------------------*/
-#define	CS_H()		bset(P0)	/* Set MMC CS "high" */
-#define CS_L()		bclr(P0)	/* Set MMC CS "low" */
-#define CK_H()		bset(P1)	/* Set MMC SCLK "high" */
-#define	CK_L()		bclr(P1)	/* Set MMC SCLK "low" */
-#define DI_H()		bset(P2)	/* Set MMC DI "high" */
-#define DI_L()		bclr(P2)	/* Set MMC DI "low" */
-#define DO			btest(P3)	/* Test MMC DO (high:true, low:false) */
-
-
-// Command listing
-/* T16: Transfer 16-bit
- * First, the 16-bit value encoded in the address bits A[17:2] is latched.
- * The data output mux is set to the current RXR and the cycle completes.
- * Shortly after /AS rises, the SPI transfer engine begins
- * transferring the latched value.
- */
-/* T16S: Transfer 16-bit Swapped
- * Same as T16L but read data is byte-swapped.
- */
-/* MERT: Measure Elapsed time and Reset Timer
- * The elapsed time since the last MERT command is returned in D[31:24]
- * and the timer is reset.
- */
-/* SKIP1: Skip Clocks with MOSI "1"
- * 
- */
-/* SKIP0: Skip Clocks with MOSI "0"
- *
- */
-/* T8S: Transfer 8-bit Swapped
- * Same as T8 but read data is byte-swapped.
- */
-/* T8: Transfer 8-bit
- * First, the 8-bit value encoded in the address bits A[9:2] is latched.
- * The data output mux is set to the current RXR and the cycle completes.
- * Shortly after /AS rises, the SPI transfer engine begins
- * transferring the latched value.
- */
-/* WRC: Write Command
- * The command encoded in address bits A[9:2] is sent to the command target
- * corresponding to the address bits A[15:10].
- * Command targets:
- *	$00 - Set bitbang
- *			A[2] - SCS value
- */
-/* RDRXR: Read Receive Data Register
- * The the current RXR is returned in D[31:16] and the cycle completes.
- */
-/* RDRXRS: Read Receive Data Register Swapped
- * Same as RDRXR but read data is byte-swapped.
- */
-/* MAGIC: Write Command
- * Write sequence $FF $00 $55 $AA $C1 $AD
- * to enable registers at $40890000-$4097FFFF.
- * Write anything else to disable them.
- * Always reads 0xC1AD
- */
-
-// SPI controller address map:
-// 40940000-4097FFFF (256 kB, D[31:16]) T16S. Write transfer data in A[17:2].
-// 40900000-4093FFFF (256 kB, D[31:16]) T16. Write transfer data in A[17:2].
-// 408C0000-408FFFFF (320 kB) reserved
-// 408A0000-408AFFFF ( 64 kB, D[31:24]) WRC. Write port address in A[15:10] and data in A[9:2].
-// 40891C00-4089FFFF ( 55 kB) reserved
-// 40892000-408923FF (  1 kB, D[31:24]) MERT.
-// 40891C00-40891FFF (  1 kB) SKIP1. Write bytes to skip in A[9:2].
-// 40891800-40891BFF (  1 kB) SKIP0. Write bytes to skip in A[9:2].
-// 40891400-408917FF (  1 kB, D[31:16]) T8S. Write transfer data in A[9:2].
-// 40891000-408913FF (  1 kB, D[31:16]) T8. Write transfer data in A[9:2].
-// 40890C00-40890FFF (  1 kB, D[31:16]) RDRXRS.
-// 40890800-40890BFF (  1 kB, D[31:16]) RDRXR.
-// 40890400-408907FF (  1 kB) reserved
-// 40890000-408903FF (  1 kB, D[31:24]) MAGIC. Write magic numbers in A[9:2].
-// 40880000-408FFFFF ( 64 kB, D[31:00]) ROMBUS driver data
-
-#define RB_T16S(x)		(*(volatile int*)	(0x40940000 + ((x && 0xFFFF)<<02)) )
-#define RB_T16(x)		(*(volatile int*)	(0x40900000 + ((x && 0xFFFF)<<02)) )
-#define RB_RDS(a)		(*(volatile char*)	(0x408B0000 + ((a && 0x003F)<<10)) )
-#define RB_WRC(a,d)		(*(volatile char*)	(0x408A0000 + ((a && 0x003F)<<10) 
-														+ ((d && 0x00FF)<<02)) )
-#define RB_MERT(x)		(*(volatile char*)	(0x40892000 + ((x && 0xFFFF)<<02)) )
-#define RB_SKIP1(n)		(*(volatile char*)	(0x40891C00 + ((x && 0xFFFF)<<02)) )
-#define RB_SKIP0(n)		(*(volatile char*)	(0x40891800 + ((x && 0xFFFF)<<02)) )
-#define RB_T8S(x)		(*(volatile int*)	(0x40891400 + ((x && 0xFFFF)<<02)) )
-#define RB_T8(x)		(*(volatile int*)	(0x40891000 + ((x && 0xFFFF)<<02)) )
-#define RB_RDRXRS		(*(volatile int*)	(0x40890C00 + ((x && 0xFFFF)<<02)) )
-#define RB_RDRXR		(*(volatile int*)	(0x40890800 + ((x && 0xFFFF)<<02)) )
-#define RB_WRMOSI(x)	(*(volatile char*)	(0x40890400 + ((x && 0x0001)<<02)) )
-#define RB_MAGIC(x)		(*(volatile char*)	(0x40890000 + ((x && 0xFFFF)<<02)) )
-
-#define SPI_GET_MISO(d)	(d & 1)
-
-void spi_select() { 
-	ret = *SPI_CMD_SEL0;
-	ret = *SPI_CMD_SEL1;
-	ret = *SPI_CMD_SEL2;
-	ret = *SPI_CMD_SEL3;
-}
-void spi_deselect() {
-	ret = *SPI_CMD_DES0;
-	ret = *SPI_CMD_DES1;
-	ret = *SPI_CMD_DES2;
-	ret = *SPI_CMD_DES3;
-}
-
-void spi_tx_slow(char d) {
-	for (int i = 0; i < 8; i++) {
-		*SPI_CMD_BBA((0 & 0x02) | (d & 0x01));
-		*SPI_CMD_BBA((1 & 0x02) | (d & 0x01));
-		d >>= 1;
-	}
-	*SPI_CMD_BBA((0 & 0x02) | (0 & 0x01));
-}
-
-char spi_rx_slow() {
-	char ret = 0;
-	for (int i = 0; i < 8; i++) {
-		*SPI_CMD_BBA((0 & 0x02) | (1 & 0x01));
-		*SPI_CMD_BBA((1 & 0x02) | (1 & 0x01));
-		ret = (ret << 1) + (*SPI_CMD_BBA((1 & 0x02) | (1 & 0x01)) & 1);
-	}
-	return ret;
-}
-
-void spi_skip_slow(int n) {
-	while (n-- > 0) {
-		for (int i = 0; i < 8; i++) {
-			*SPI_CMD_BBA((0 & 0x02) | (1 & 0x01));
-			*SPI_CMD_BBA((1 & 0x02) | (1 & 0x01));
-		}
-	}
-	*SPI_CMD_BBA((0 & 0x02) | (1 & 0x01));
-}
-
-void spi_tx_8(char d) {
-	*SPI_CMD_SH8(d);
-}
-
-char spi_rx_8() {
-	*SPI_CMD_SH8(0xFF);
-	return *SPI_CMD_RD & 0xFF;
-}
-
-void spi_tx_16(int d) {
-	*SPI_CMD_SH16(d);
-}
-
-int spi_rx_16() {
-	*SPI_CMD_SH16(0xFFFF);
-	return *SPI_CMD_RD & 0xFFFF;
-}
-
-void spi_skip(int n) {
-	while (n-- > 0) {
-		for (int i = 0; i < 8; i++) {
-			*SPI_CMD_SH8(0xFF);
-		}
-	}
-}
diff --git a/old/spi.h b/old/spi.h
deleted file mode 100644
index 70ee2c5..0000000
--- a/old/spi.h
+++ /dev/null
@@ -1,17 +0,0 @@
-#ifndef SPI_H
-#define SPI_H
-
-void spi_select();
-void spi_deselect();
-
-void spi_tx_slow(char d);
-char spi_rx_slow();
-void spi_skip_slow(int n);
-
-void spi_tx_8(char d);
-char spi_rx_8();
-void spi_tx_16(int d);
-int spi_rx_16();
-void spi_skip(int n);
-
-#endif
diff --git a/old/xfer.h b/old/xfer.h
deleted file mode 100644
index bc81450..0000000
--- a/old/xfer.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef RDISK_H
-#define RDISK_H
-
-#pragma parameter xfer_s_256(__A0, __A1)
-void xfer_s_256(Ptr srcreg, Ptr destmem);
-
-#pragma parameter xfer_s(__D0, __A0, __A1)
-void xfer_s(uint8_t numBytes, Ptr srcreg, Ptr destmem);
-
-
-#endif
diff --git a/old/xfer.s b/old/xfer.s
deleted file mode 100644
index 2c9b1d6..0000000
--- a/old/xfer.s
+++ /dev/null
@@ -1,34 +0,0 @@
-	.macro  	xfer_in	from, to
-	move.w		(%A0), (%A1)+
-	nop
-	nop
-	nop
-	.if			\to-\from
-	xfer_in	"(\from+1)"
-	.else
-	
-	.endif
-	.endm
-
-
-;pragma parameter xfer_s_256(__A0, __A1)
-;void xfer_s_256(Ptr srcreg, Ptr destmem);
-xfer_256:
-	movem.l		%D0/%A1-%A2, -(%SP)
-xfer_256_loop:
-	xfer_s_in	0, 255
-xfer_256_end:
-	movem.l		(%SP)+, %D0/%A1-%A2
-
-
-;pragma parameter xfer_s(__D0, __A0, __A1)
-;void xfer_s(uint8_t numBytes, Ptr srcreg, Ptr destmem);
-xfer:
-	movem.l		%D0/%A1-%A2, -(%SP)
-	andi.l 		#0xFF, %D0
-	subi.l 		#256, %D0
-	neg.l 		%D0
-	lsl.l 		#2, %D0
-	addi.l 		#xfer_256, %D0
-	movea.l 	%D0, %A2
-	jmp 		%A2
diff --git a/priv_syscall.h b/priv_syscall.h
new file mode 100644
index 0000000..496bb3a
--- /dev/null
+++ b/priv_syscall.h
@@ -0,0 +1,23 @@
+#ifndef _PRIV_SYSCALL_H
+#define _PRIV_SYSCALL_H
+
+#include <Disks.h>
+#include <OSUtils.h>
+
+#pragma parameter __D0 PSReadXPRAM(__D0, __D1, __A0)
+OSErr PSReadXPRAM(short numBytes, short whichByte, Ptr dest) = {0x4840, 0x3001, 0xA051};
+
+#pragma parameter __D0 PSAddDrive(__D1, __D0, __A0)
+OSErr PSAddDrive(short drvrRefNum, short drvNum, DrvQElPtr dq) = {0x4840, 0x3001, 0xA04E};
+
+// Figure out the first available drive number >= 5
+static int PSFindDrvNum() {
+	DrvQElPtr dq;
+	int drvNum = 5;
+	for (dq = (DrvQElPtr)(GetDrvQHdr())->qHead; dq; dq = (DrvQElPtr)dq->qLink) {
+		if (dq->dQDrive >= drvNum) { drvNum = dq->dQDrive + 1; }
+	}
+	return drvNum;
+}
+
+#endif
diff --git a/rdisk.c b/rdisk.c
deleted file mode 100644
index 9e081c7..0000000
--- a/rdisk.c
+++ /dev/null
@@ -1,100 +0,0 @@
-#include <Memory.h>
-#include <Devices.h>
-#include <Files.h>
-#include <Disks.h>
-#include <Errors.h>
-#include <Events.h>
-#include <OSUtils.h>
-#include <Quickdraw.h>
-
-#include "rombus.h"
-#include "rdisk.h"
-
-OSErr RDOpen(IOParamPtr p, DCtlPtr d, RBStorage_t *c) {
-	// Find first available drive number for ROM drive
-	drvNum = RBFindDrvNum();
-	// Set ROM drive status
-	c->rdStatus.track = 0;
-	c->rdStatus.writeProt = -1; // nonzero is write protected
-	c->rdStatus.diskInPlace = 8; // 8 is nonejectable disk
-	c->rdStatus.installed = 1; // drive installed
-	c->rdStatus.sides = 0;
-	c->rdStatus.qType = 0;
-	c->rdStatus.dQDrive = drvNum;
-	c->rdStatus.dQFSID = 0;
-	c->rdStatus.dQRefNum = d->dCtlRefNum;
-	c->rdStatus.driveSize = RDiskSize / 512;
-	//c->rdStatus.driveS1 = (RDiskSize / 512) >> 16;
-	// Decompress ROM disk icon
-	src = &RDiskIconCompressed[0];
-	dst = &c->rdIcon[0];
-	UnpackBits(&src, &dst, RDISK_ICON_SIZE);
-	// Add ROM disk to drive queue and return
-	return RBAddDrive(c->rdStatus.dQRefNum, c->rdStatus.dQDrive, (DrvQElPtr)&c->rdStatus.qLink);
-}
-
-OSErr RDPrime(IOParamPtr p, DCtlPtr d, RBStorage_t *c) {
-	// Return disk offline error if virtual disk not inserted
-	if (!c->rdStatus.diskInPlace) { return offLinErr; }
-
-	// Get pointer to ROM disk buffer
-	disk = RDiskBuf + d->dCtlPosition;
-	//  Bounds checking
-	if (d->dCtlPosition >= RDiskSize || p->ioReqCount >= RDiskSize || 
-		d->dCtlPosition + p->ioReqCount >= RDiskSize) { return paramErr; }
-
-	// Service read or write request
-	cmd = p->ioTrap & 0x00FF;
-	if (cmd == aRdCmd) { // Read
-		// Read from disk into buffer.
-		if (*MMU32bit) { BlockMove(disk, p->ioBuffer, p->ioReqCount); }
-		else { copy24(disk, StripAddress(p->ioBuffer), p->ioReqCount); }
-	} else if (cmd == aWrCmd) { return wPrErr;
-	} else { return noErr; } //FIXME: Fail if cmd isn't read or write?
-
-	// Update count and 1position/offset, then return
-	d->dCtlPosition += p->ioReqCount;
-	p->ioActCount = p->ioReqCount;
-	return noErr;
-}
-
-OSErr RDCtl(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c) {
-	// Handle control request based on csCode
-	switch (p->csCode) {
-		case kFormat: return controlErr;
-		case kVerify:
-			if (!c->rdStatus.diskInPlace) { return controlErr; }
-			return noErr;
-		case kEject:
-			// "Reinsert" disk if ejected illegally
-			if (c->rdStatus.diskInPlace) { 
-				PostEvent(diskEvt, c->rdStatus.dQDrive);
-			}
-			return controlErr; // Eject not allowed so return error
-		case kDriveIcon: case kMediaIcon: // Get icon
-			*(Ptr*)p->csParam = (Ptr)c->rdIcon;
-			return noErr;
-		case kDriveInfo:
-			//  high word (bytes 2 & 3) clear
-			//  byte 1 = primary + fixed media + internal
-			//  byte 0 = drive type (0x10 is RAM disk) / (0x11 is ROM disk)
-			*(long*)p->csParam = 0x00000411;
-			return noErr;
-		case 24: // Return SCSI partition size
-			*(long*)p->csParam = RDiskSize / 512;
-			return noErr;
-		default: return controlErr;
-	}
-}
-
-OSErr RDStat(IOParamPtr p, DCtlPtr d, RBStorage_t *c) {
-	// Handle status request based on csCode
-	switch (p->csCode) {
-		case kDriveStatus:
-			BlockMove(&c->rdStatus, &p->csParam, sizeof(DrvSts2));
-			return noErr;
-		default: return statusErr;
-	}
-}
-
-void RDClose(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c) { }
diff --git a/rdisk.h b/rdisk.h
deleted file mode 100644
index 5579401..0000000
--- a/rdisk.h
+++ /dev/null
@@ -1,101 +0,0 @@
-#ifndef RDISK_H
-#define RDISK_H
-
-#include "rombus.h"
-
-#define RDiskBuf ((char*)0x40880000)
-#define RDiskSize (*(const unsigned long*)0x40851D98)
-
-OSErr RDOpen(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr RDInit(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr RDPrime(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr RDCtl(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr RDStat(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr RDClose(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-
-#define RDISK_ICON_SIZE (285)
-#define RDISK_COMPRESSED_ICON_SIZE (87)
-const char RDiskIconCompressed[RDISK_COMPRESSED_ICON_SIZE] = {
-	PackBits_Repeat(76), 0b00000000, /*
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
-	PackBits_Repeat(4), 0b11111111, /*
-	0b11111111, 0b11111111, 0b11111111, 0b11111111, */
-	PackBits_Literal(36),
-	0b10000000, 0b00000000, 0b00000000, 0b00000001,
-	0b10001111, 0b00011110, 0b00111100, 0b01111001,
-	0b10001001, 0b00010010, 0b00100100, 0b01001001,
-	0b10001001, 0b00010010, 0b00100100, 0b01001001,
-	0b10001001, 0b00010010, 0b00100100, 0b01001001,
-	0b10001111, 0b00011110, 0b00111100, 0b01111001,
-	0b11000000, 0b00000000, 0b00000000, 0b00000001,
-	0b01010101, 0b01010101, 0b11010101, 0b01010101,
-	0b01111111, 0b11111111, 0b01111111, 0b11111111,
-	PackBits_Repeat(12), 0b00000000, /*
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
-	
-	PackBits_Repeat(76), 0b00000000, /*
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
-	PackBits_Repeat(32), 0b11111111, /*
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111, */
-	PackBits_Literal(1), 0b01111111, 
-	PackBits_Repeat(3), 0b11111111, /*
-	0b01111111, 0b11111111, 0b11111111, 0b11111111, */
-	PackBits_Literal(1), 0b01111111, 
-	PackBits_Repeat(3), 0b11111111, /*
-	0b01111111, 0b11111111, 0b11111111, 0b11111111, */
-	PackBits_Repeat(12), 0b00000000, /*
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
-	PackBits_Literal(29),
-	27, 'G', 'a', 'r', 'r', 'e', 't', 't', '\'', 's', ' ', 
-	'W', 'o', 'r', 'k', 's', 'h', 'o', 'p', ' ', 
-	'R', 'O', 'M', ' ', 'D', 'i', 's', 'k', 0
-};
-
-#endif
diff --git a/rombus.c b/rombus.c
index 669a850..67b5406 100644
--- a/rombus.c
+++ b/rombus.c
@@ -5,53 +5,71 @@
 #include <Errors.h>
 #include <Events.h>
 #include <OSUtils.h>
-#include <Quickdraw.h>
 
 #include "rombus.h"
-#include "rdisk.h"
-#include "sdisk.h"
+#include "spi.h"
+#include "priv_syscall.h"
 
-// Decode keyboard/PRAM settings
-static void RBDecodeSettings(Ptr unmountROM, Ptr unmountSD, Ptr mountSD) {
+// Decode keyboard settings
+static void RBDecodeKeySettings(RBStorage_t *c) {
 	// Sample R, S, X keys repeatedly
 	char r = 0, s = 0, x = 0;
 	long tmax = TickCount() + 60;
 	for (long i = 0; i < 1000000; i++) {
-		r |= RBIsRPressed();
-		s |= RBIsSPressed();
-		x |= RBIsXPressed();
+		r |= IsRPressed();
+		s |= IsSPressed();
+		x |= IsXPressed();
 		if (r || s || x) { break; }
 		if (TickCount() > tmax) { break; }
 	}
-
-	// Read PRAM
-	char legacy_startup;
-	RBReadXPRAM(1, 4, &legacy_startup);
-
-	// Decode settings: unmount (don't boot), mount (after boot), RAM disk
-	if (x) { // X disables SD
-		*unmountROM = 1; // Unmount ROM disk volume
-		*unmountSD = 1; // Unmount SD volume
-		*mountSD = 0; // Don't mount SD later
-	} else if (r) { // R boots from ROM disk and mount SD later
-		*unmountROM = 0; // Don't unmount so we boot from ROM
-		*unmountSD = 1; // Unmount SD volume so we don't boot from it
-		*mountSD = 1; // Mount SD later
-	} else if (s) { // S boots from SD
-		*unmountROM = 1; // Unmount ROM disk volume so we don't boot from it
-		*unmountSD = 0; // Don't unmount so we boot from SD
-		*mountSD = 0; // No need to mount SD later since already mounted
-	} else if (legacy_startup & 0x04) { // Boot from SD
-		*unmountROM = 1; // Unmount ROM disk volume so we don't boot from it
-		*unmountSD = 0; // Don't unmount so we boot from SD
-		*mountSD = 0; // No need to mount later since already mounted
-	} else {
-		*unmountROM = !(legacy_startup & 0x01); // Unmount ROM disk if saved in PRAM
-		*unmountSD = 1; // Unmount SD volume so we don't boot from it
-		*mountSD =  !(legacy_startup & 0x08); // Mount SD later if setting
+	// Decode settings
+	if (x) { // Unmount everything
+		c->unmountROMEN = 1;
+		c->unmountSDEN = 1;
+		c->mountROMEN = 0;
+		c->mountSDEN = 0;
+	} else if (s) { // Boot from SD, don't mount ROM
+		c->unmountROMEN = 1;
+		c->unmountSDEN = 0;
+		c->mountROMEN = 1;
+		c->mountSDEN = 0;
+	} else if (r) { // Boot from ROM, mount SD
+		c->unmountROMEN = 0;
+		c->unmountSDEN = 1;
+		c->mountROMEN = 0;
+		c->mountSDEN = 1;
 	}
 }
 
+// Decode PRAM settings
+static OSErr RBDecodePRAMSettings(RBStorage_t *c) {
+	// Read PRAM
+	char legacy_startup, legacy_ram;
+	PSReadXPRAM(1, 4, &legacy_startup);
+	PSReadXPRAM(1, 5, &legacy_ram);
+	
+	// Decoded settings
+	const char opt_disable   = legacy_startup & (1<<7);
+	const char opt_boot_sd   = legacy_startup & (1<<2);
+	const char opt_boot_rom  = legacy_startup & (1<<0);
+	const char opt_mount_sd  = legacy_startup & (1<<3);
+	const char opt_mount_rom = legacy_startup & (1<<4);
+
+	// Old settings for ROM SIMM (not used here)
+	//const char opt_old_mount_rom = !(legacy_startup & (1<<1));
+	//const char opt_old_ram       = legacy_ram & (1<<0);
+
+	// Set based on decoded settings
+	if (opt_disable) { return -1; }
+	else {
+		c->unmountROMEN = !opt_boot_rom;
+		c->unmountSDEN = !opt_boot_sd;
+		c->mountROMEN = opt_mount_rom && !opt_boot_rom;
+		c->mountSDEN = opt_mount_sd && !opt_boot_sd;
+	}
+	return noErr;
+}
+
 // Switch to 32-bit mode and copy
 #pragma parameter C24(__A0, __A1, __D0)
 void __attribute__ ((noinline)) C24(Ptr sourcePtr, Ptr destPtr, unsigned long byteCount) {
@@ -61,31 +79,24 @@ void __attribute__ ((noinline)) C24(Ptr sourcePtr, Ptr destPtr, unsigned long by
 	SwapMMUMode(&mode);
 }
 
-// Figure out the first available drive number >= 5
-static int RBFindDrvNum() {
-	DrvQElPtr dq;
-	int drvNum = 5;
-	for (dq = (DrvQElPtr)(GetDrvQHdr())->qHead; dq; dq = (DrvQElPtr)dq->qLink) {
-		if (dq->dQDrive >= drvNum) { drvNum = dq->dQDrive + 1; }
-	}
-	return drvNum;
+#pragma parameter __D0 RBClose(__A0, __A1)
+OSErr RBClose(IOParamPtr p, DCtlPtr d) {
+	// If dCtlStorage not null, dispose of it
+	if (!d->dCtlStorage) { return noErr; }
+	HUnlock(d->dCtlStorage);
+	DisposeHandle(d->dCtlStorage);
+	d->dCtlStorage = NULL;
+	return noErr;
 }
 
 #pragma parameter __D0 RBOpen(__A0, __A1)
 OSErr RBOpen(IOParamPtr p, DCtlPtr d) {
 	int drvNum;
 	RBStorage_t *c;
-	char legacy_startup;
-	char *src, *dst;
-	OSErr ret;
 
 	// Do nothing if already opened
 	if (d->dCtlStorage) { return noErr; }
 
-	// Do nothing if inhibited
-	RBReadXPRAM(1, 4, &legacy_startup);
-	if (legacy_startup & 0x80) { return noErr; } 
-
 	// Allocate storage struct
 	d->dCtlStorage = NewHandleSysClear(sizeof(RBStorage_t));
 	if (!d->dCtlStorage) { return openErr; }
@@ -94,36 +105,67 @@ OSErr RBOpen(IOParamPtr p, DCtlPtr d) {
 	HLock(d->dCtlStorage);
 	c = *(RBStorage_t**)d->dCtlStorage;
 
-	// Populate both drives' DrvSts and add each to drive queue
-	if (ret = RDOpen(p, d ,c) != noErr) { return ret; }	
-	if (ret = SDOpen(p, d ,c) != noErr) { return ret; }	
+	// Do nothing if inhibited
+	if (RBDecodePRAMSettings(c) != noErr) {
+		RBClose(p, d);
+		return openErr;
+	}
+
+	// Iff mount enabled, enable accRun to post disk inserted event later
+	if (c->mountROMEN || c->mountSDEN) { d->dCtlFlags |= dNeedTimeMask; }
+	else { d->dCtlFlags &= ~dNeedTimeMask; }
+
+	// Set accRun delay
+	d->dCtlDelay = 150; // (150 ticks is 2.5 sec.)
+
+	// Find first available drive number
+	drvNum = PSFindDrvNum();
+
+	//TODO: set c->sdSize
+	
+	// Set drive status
+	c->sdStatus.track = 0;
+	c->sdStatus.writeProt = 0; // nonzero is write protected
+	c->sdStatus.diskInPlace = 8; // 8 is nonejectable disk
+	c->sdStatus.installed = 1; // drive installed
+	c->sdStatus.sides = 0;
+	c->sdStatus.qType = 1;
+	c->sdStatus.dQDrive = drvNum;
+	c->sdStatus.dQFSID = 0;
+	c->sdStatus.dQRefNum = d->dCtlRefNum;
+	c->sdStatus.driveSize = c->sdSize / 512;
+	c->sdStatus.driveS1 = (c->sdSize / 512) >> 16;
+
+	// Decompress icon
+	#ifdef RB_COMPRESS_ICON_ENABLE
+	char *src = &SDIconCompressed[0];
+	char *dst = &c->sd[0];
+	UnpackBits(&src, &dst, RB_ICON_SIZE);
+	#endif
+
+	// Add drive to drive queue and return
+	PSAddDrive(c->sdStatus.dQRefNum, drvNum, (DrvQElPtr)&c->sdStatus.qLink);
 	return noErr;
 }
 
 // Init is called at beginning of first prime (read/write) call
-static void RBInit(IOParamPtr p, DCtlPtr d, RBStorage_t *c) {
-	char unmountROM, unmountSD;
+static void RBBootInit(IOParamPtr p, DCtlPtr d, RBStorage_t *c) {
 	// Mark init done
 	c->initialized = 1;
-	// Decode settings
-	RBDecodeSettings(&unmountROM, &c->mountROM, &unmountSD, &c->mountSD);
 
-	// Unmount if requested
-	if (unmountROM) { c->rdStatus.diskInPlace = 0; }
-	if (unmountSD) { c->sdStatus.diskInPlace = 0; }
+	// Decode key settings
+	RBDecodeKeySettings(c);
 
-	// If mount enabled, enable accRun to post disk inserted event later
-	if (c->mountROM || c->mountSD) { 
-		d->dCtlDelay = 150; // Set accRun delay (150 ticks is 2.5 sec.)
-		d->dCtlFlags |= dNeedTimeMask; // Enable accRun
-	}
+	// Unmount if not booting from ROM disk
+	if (c->unmountSDEN) { c->sdStatus.diskInPlace = 0; }
+
+	// Iff mount disabled, disable accRun
+	if (!c->mountSDEN || !c->mountROMEN) { d->dCtlFlags &= ~dNeedTimeMask; }
 }
 
 #pragma parameter __D0 RBPrime(__A0, __A1)
 OSErr RBPrime(IOParamPtr p, DCtlPtr d) {
 	RBStorage_t *c;
-	char cmd;
-	Ptr disk;
 
 	// Return disk offline error if dCtlStorage null
 	if (!d->dCtlStorage) { return notOpenErr; }
@@ -131,13 +173,17 @@ OSErr RBPrime(IOParamPtr p, DCtlPtr d) {
 	c = *(RBStorage_t**)d->dCtlStorage;
 
 	// Initialize if this is the first prime call
-	if (!c->initialized) { RBInit(p, d, c); }
+	if (!c->initialized) { RBBootInit(p, d, c); }
 
-	switch (p->ioVRefNum) {
-		case c->rdStatus.dQDrive: return RDPrime(p, d, c);
-		case c->sdStatus.dQDrive: return SDPrime(p, d, c);
-		default: return statusErr;
-	}
+	// Return disk offline error if virtual disk not inserted
+	if (!c->sdStatus.diskInPlace) { return offLinErr; }
+
+	//TODO: Read/write
+
+	// Update count and position/offset, then return
+	d->dCtlPosition += p->ioReqCount;
+	p->ioActCount = p->ioReqCount;
+	return noErr;
 }
 
 #pragma parameter __D0 RBCtl(__A0, __A1)
@@ -147,60 +193,60 @@ OSErr RBCtl(CntrlParamPtr p, DCtlPtr d) {
 	if (!d->dCtlStorage) { return notOpenErr; }
 	// Dereference dCtlStorage to get pointer to our context
 	c = *(RBStorage_t**)d->dCtlStorage;
-	// Handle control request csCodes common to both volumes
+	// Handle control request based on csCode
 	switch (p->csCode) {
-		case killCode: return noErr;
-		case accRun:
-			if (c->mountSD) { // Request to mount SD disk
-				c->sdStatus.diskInPlace = 8; // 8 is nonejectable disk
-				PostEvent(diskEvt, c->sdStatus.dQDrive); // Post disk inserted event
-				return noErr;
-			} else if (c->mountROM) { // Request to mount ROM disk
-				c->rdStatus.diskInPlace = 8; // 8 is nonejectable disk
-				PostEvent(diskEvt, c->rdStatus.dQDrive); // Post disk inserted event
-				return noErr;
-			} else { // Nothing to mount
-				d->dCtlFlags &= ~dNeedTimeMask; // Disable accRun
-				return noErr;
+		case kFormat:
+			if (!c->sdStatus.diskInPlace || c->sdStatus.writeProt) {
+				return controlErr;
 			}
-		case 2351: // Post-boot
-			c->initialized = 1; // Skip initialization
-			d->dCtlDelay = 30; // Set accRun delay (30 ticks is 0.5 sec.)
-			d->dCtlFlags |= dNeedTimeMask; // Enable accRun
+			//TODO: Format
 			return noErr;
-	}
-	// Dispatch based on volume reference number
-	switch (p->ioVRefNum) {
-		case c->rdStatus.dQDrive: return RDCtl(p, d, c);
-		case c->sdStatus.dQDrive: return SDCtl(p, d, c);
+		case kVerify:
+			if (!c->sdStatus.diskInPlace) { return controlErr; }
+			return noErr;
+		case accRun:
+			c->initialized = 1; // Mark init done
+			c->sdStatus.diskInPlace = 8; // 8 is nonejectable disk
+			PostEvent(diskEvt, c->sdStatus.dQDrive); // Post disk inserted event
+			d->dCtlFlags &= ~dNeedTimeMask; // Disable accRun
+			return noErr;
+		case kDriveIcon: case kMediaIcon: // Get icon
+			#ifdef RB_COMPRESS_ICON_ENABLE
+			*(Ptr*)p->csParam = (Ptr)c->sd;
+			#else
+			*(Ptr*)p->csParam = (Ptr)RDiskIcon;
+			#endif
+			return noErr;
+		case kDriveInfo:
+			//  high word (bytes 2 & 3) clear
+			//  byte 1 = primary + fixed media + internal
+			//  byte 0 = drive type (0x10 is RAM disk) / (0x11 is ROM disk)
+			if (c->sdStatus.writeProt) { *(long*)p->csParam = 0x00000400; }
+			else { *(long*)p->csParam = 0x00000400; }
+			return noErr;
+		case 24: // Return SCSI partition size
+			*(long*)p->csParam = c->sdSize / 512;
+			return noErr;
+		case killCode: return noErr;
+		case kEject:
+			// "Reinsert" disk if ejected illegally
+			if (c->sdStatus.diskInPlace) { 
+				PostEvent(diskEvt, c->sdStatus.dQDrive);
+			}
+			return controlErr; // Eject not allowed so return error
 		default: return controlErr;
 	}
 }
 
 #pragma parameter __D0 RBStat(__A0, __A1)
 OSErr RBStat(CntrlParamPtr p, DCtlPtr d) {
-	RBStorage_t *c;
 	// Fail if dCtlStorage null
 	if (!d->dCtlStorage) { return notOpenErr; }
-	// Dereference dCtlStorage to get pointer to our context
-	c = *(RBStorage_t**)d->dCtlStorage;
-	// Dispatch based on volume reference number
-	switch (p->ioVRefNum) {
-		case c->rdStatus.dQDrive: return RDStat(p, d, c);
-		case c->sdStatus.dQDrive: return SDStat(p, d, c);
+	// Handle status request based on csCode
+	switch (p->csCode) {
+		case kDriveStatus:
+			BlockMove(*d->dCtlStorage, &p->csParam, sizeof(DrvSts2));
+			return noErr;
 		default: return statusErr;
 	}
 }
-
-#pragma parameter __D0 RBClose(__A0, __A1)
-OSErr RBClose(IOParamPtr p, DCtlPtr d) {
-	// If dCtlStorage not null, dispose of it
-	if (!d->dCtlStorage) { return noErr; }
-	RBStorage_t *c = *(RBStorage_t**)d->dCtlStorage;
-	RDClose(p, d, c);
-	SDClose(p, d, c);
-	HUnlock(d->dCtlStorage);
-	DisposeHandle(d->dCtlStorage);
-	d->dCtlStorage = NULL;
-	return noErr;
-}
diff --git a/rombus.h b/rombus.h
index 65176b9..7716963 100644
--- a/rombus.h
+++ b/rombus.h
@@ -1,36 +1,201 @@
-#ifndef ROMBUS_H
-#define ROMBUS_H
+#ifndef _RDISK_H
+#define _RDISK_H
 
-#define BufPtr ((Ptr*)0x10C)
-#define MemTop ((Ptr*)0x108)
+#define RDiskBuf ((char*)0x40880000)
 #define MMU32bit ((char*)0xCB2)
 
-#pragma parameter __D0 RBReadXPRAM(__D0, __D1, __A0)
-OSErr RBReadXPRAM(short numBytes, short whichByte, Ptr dest) = {0x4840, 0x3001, 0xA051};
+#define RDiskDBGDisPos (*(const unsigned long*)0x40851D98)
+#define RDiskCDRDisPos (*(const unsigned long*)0x40851D9C)
+#define RDiskDBGDisByte (*(const char*)0x40851DA8)
+#define RDiskCDRDisByte (*(const char*)0x40851DA9)
+#define RDiskSize (*(const unsigned long*)0x40851DAC)
 
-#pragma parameter __D0 RBAddDrive(__D1, __D0, __A0)
-OSErr RBAddDrive(short drvrRefNum, short drvNum, DrvQElPtr dq) = {0x4840, 0x3001, 0xA04E};
+#define RB_COMPRESS_ICON_ENABLE
 
-static inline char RBIsSPressed() { return *((volatile char*)0x174) & 0x02; }
-static inline char RBIsXPressed() { return *((volatile char*)0x174) & 0x80; }
-static inline char RBIsRPressed() { return *((volatile char*)0x175) & 0x80; }
+static inline char IsRPressed() { return *((volatile char*)0x175) & 0x80; }
+static inline char IsSPressed() { return *((volatile char*)0x174) & 0x02; }
+static inline char IsXPressed() { return *((volatile char*)0x174) & 0x80; }
 
-#define RDISK_ICON_SIZE (285)
-#define SDISK_ICON_SIZE (285)
-typedef struct RBStorage_s {
-	DrvSts2 rdStatus;
+#define RB_ICON_SIZE (285)
+typedef struct RDiskStorage_s {
 	DrvSts2 sdStatus;
+	long long sdSize;
+
 	char initialized;
-	char mountROM;
-	char mountSD;
-	char rdIcon[RDISK_ICON_SIZE+8];
-	char sdIcon[SDISK_ICON_SIZE+8];
+
+	char unmountSDEN;
+	char mountSDEN;
+	char unmountROMEN;
+	char mountROMEN;
+
+	#ifdef RB_COMPRESS_ICON_ENABLE
+	char sd[RB_ICON_SIZE+8];
+	#endif
 } RBStorage_t;
 
-typedef void (*RBCopy_t)(Ptr, Ptr, unsigned long);
-#define copy24(s, d, b) { RBCopy_t f = C24; f(s, d, b); }
+typedef void (*RDiskCopy_t)(Ptr, Ptr, unsigned long);
+#define copy24(s, d, b) { RDiskCopy_t f = C24; f(s, d, b); }
 
 #define PackBits_Repeat(count) (-1 * (count - 1))
 #define PackBits_Literal(count) (count - 1)
 
+#define RDISK_COMPRESSED_ICON_SIZE (87)
+#ifdef RB_COMPRESS_ICON_ENABLE
+#include <Quickdraw.h>
+const char SDIconCompressed[RDISK_COMPRESSED_ICON_SIZE] = {
+	PackBits_Repeat(76), 0b00000000, /*
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
+	PackBits_Repeat(4), 0b11111111, /*
+	0b11111111, 0b11111111, 0b11111111, 0b11111111, */
+	PackBits_Literal(36),
+	0b10000000, 0b00000000, 0b00000000, 0b00000001,
+	0b10001111, 0b00011110, 0b00111100, 0b01111001,
+	0b10001001, 0b00010010, 0b00100100, 0b01001001,
+	0b10001001, 0b00010010, 0b00100100, 0b01001001,
+	0b10001001, 0b00010010, 0b00100100, 0b01001001,
+	0b10001111, 0b00011110, 0b00111100, 0b01111001,
+	0b11000000, 0b00000000, 0b00000000, 0b00000001,
+	0b01010101, 0b01010101, 0b11010101, 0b01010101,
+	0b01111111, 0b11111111, 0b01111111, 0b11111111,
+	PackBits_Repeat(12), 0b00000000, /*
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
+	
+	PackBits_Repeat(76), 0b00000000, /*
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
+	PackBits_Repeat(32), 0b11111111, /*
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111, */
+	PackBits_Literal(1), 0b01111111, 
+	PackBits_Repeat(3), 0b11111111, /*
+	0b01111111, 0b11111111, 0b11111111, 0b11111111, */
+	PackBits_Literal(1), 0b01111111, 
+	PackBits_Repeat(3), 0b11111111, /*
+	0b01111111, 0b11111111, 0b11111111, 0b11111111, */
+	PackBits_Repeat(12), 0b00000000, /*
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
+	PackBits_Literal(29),
+	27, 'G', 'a', 'r', 'r', 'e', 't', 't', '\'', 's', ' ', 
+	'W', 'o', 'r', 'k', 's', 'h', 'o', 'p', ' ', 
+	'R', 'O', 'M', ' ', 'D', 'i', 's', 'k', 0
+};
+#else
+const char RDiskIcon[RB_ICON_SIZE] = {
+	// Icon
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b10000000, 0b00000000, 0b00000000, 0b00000001,
+	0b10001111, 0b00011110, 0b00111100, 0b01111001,
+	0b10001001, 0b00010010, 0b00100100, 0b01001001,
+	0b10001001, 0b00010010, 0b00100100, 0b01001001,
+	0b10001001, 0b00010010, 0b00100100, 0b01001001,
+	0b10001111, 0b00011110, 0b00111100, 0b01111001,
+	0b11000000, 0b00000000, 0b00000000, 0b00000001,
+	0b01010101, 0b01010101, 0b11010101, 0b01010101,
+	0b01111111, 0b11111111, 0b01111111, 0b11111111,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	// Mask
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b11111111, 0b11111111, 0b11111111, 0b11111111,
+	0b01111111, 0b11111111, 0b11111111, 0b11111111,
+	0b01111111, 0b11111111, 0b11111111, 0b11111111,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	0b00000000, 0b00000000, 0b00000000, 0b00000000,
+	27, 'G', 'a', 'r', 'r', 'e', 't', 't', '\'', 's', ' ', 
+	'W', 'o', 'r', 'k', 's', 'h', 'o', 'p', ' ', 
+	'R', 'O', 'M', ' ', 'D', 'i', 's', 'k', 0
+};
+#endif
+
 #endif
diff --git a/sdisk.c b/sdisk.c
deleted file mode 100644
index 5763945..0000000
--- a/sdisk.c
+++ /dev/null
@@ -1,99 +0,0 @@
-#include <Memory.h>
-#include <Devices.h>
-#include <Files.h>
-#include <Disks.h>
-#include <Errors.h>
-#include <Events.h>
-#include <OSUtils.h>
-#include <Quickdraw.h>
-
-#include "rombus.h"
-#include "sdisk.h"
-
-static char SPI_SetCS(char cs) {
-	
-}
-
-static void SPI_TX8(char d) {
-	
-}
-
-static char SPI_RX8(char d) {
-	
-}
-
-static void SPI_TX8_Slow(char d) {
-	
-}
-
-static char SPI_RX8_Slow(char d) {
-	
-}
-
-OSErr SDOpen(IOParamPtr p, DCtlPtr d, RBStorage_t *c) {
-	// Find first available drive number for SD drive
-	drvNum = RBFindDrvNum();
-	// Set SD drive status
-	c->sdStatus.track = 0;
-	c->sdStatus.writeProt = 0; // zero is writable
-	c->sdStatus.diskInPlace = 8; // 8 is nonejectable disk
-	c->sdStatus.installed = 1; // drive installed
-	c->sdStatus.sides = 0;
-	c->sdStatus.qType = 1;
-	c->sdStatus.dQDrive = drvNum;
-	c->sdStatus.dQFSID = 0;
-	c->sdStatus.dQRefNum = d->dCtlRefNum;
-	c->sdStatus.driveSize = SDiskSize / 512;
-	c->sdStatus.driveS1 = (SDiskSize / 512) >> 16;
-	// Decompress SD disk icon
-	src = &SDiskIconCompressed[0];
-	dst = &c->sdIcon[0];
-	UnpackBits(&src, &dst, SDISK_ICON_SIZE);
-	// Add SD disk to drive queue and return
-	return RBAddDrive(c->sdStatus.dQRefNum, c->sdStatus.dQDrive, (DrvQElPtr)&c->sdStatus.qLink);
-}
-
-OSErr SDPrime(IOParamPtr p, DCtlPtr d, RBStorage_t *c) {
-	return controlErr;
-}
-
-OSErr SDCtl(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c) {
-	// Handle control request based on csCode
-	switch (p->csCode) {
-		case kFormat: return controlErr;
-		case kVerify:
-			if (!c->sdStatus.diskInPlace) { return controlErr; }
-			return noErr;
-		case kEject:
-			// "Reinsert" disk if ejected illegally
-			if (c->sdStatus.diskInPlace) { 
-				PostEvent(diskEvt, c->sdStatus.dQDrive);
-			}
-			return controlErr; // Eject not allowed so return error
-		case kDriveIcon: case kMediaIcon: // Get icon
-			*(Ptr*)p->csParam = (Ptr)c->sdIcon;
-			return noErr;
-		case kDriveInfo:
-			//  high word (bytes 2 & 3) clear
-			//  byte 1 = primary + fixed media + internal
-			//  byte 0 = drive type (0x00 is ??)
-			*(long*)p->csParam = 0x00000400;
-			return noErr;
-		case 24: // Return SCSI partition size
-			*(long*)p->csParam = SDiskSize / 512;
-			return noErr;
-		default: return controlErr;
-	}
-}
-
-OSErr SDStat(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c) {
-	// Handle status request based on csCode
-	switch (p->csCode) {
-		case kDriveStatus:
-			BlockMove(&c->sdStatus, &p->csParam, sizeof(DrvSts2));
-			return noErr;
-		default: return statusErr;
-	}
-}
-
-void SDClose(IOParamPtr p, DCtlPtr d, RBStorage_t *c) { }
diff --git a/sdisk.h b/sdisk.h
deleted file mode 100644
index 53357af..0000000
--- a/sdisk.h
+++ /dev/null
@@ -1,100 +0,0 @@
-#ifndef SDISK_H
-#define SDISK_H
-
-#include "rombus.h"
-
-#define SDiskSize (*(const unsigned long*)0x40851D9C)
-
-OSErr SDOpen(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr SDInit(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr SDPrime(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr SDCtl(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr SDStat(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-OSErr SDClose(CntrlParamPtr p, DCtlPtr d, RBStorage_t *c);
-
-#define SDISK_ICON_SIZE (285)
-#define SDISK_COMPRESSED_ICON_SIZE (86)
-const char SDiskIconCompressed[SDISK_COMPRESSED_ICON_SIZE] = {
-	PackBits_Repeat(76), 0b00000000, /*
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
-	PackBits_Repeat(4), 0b11111111, /*
-	0b11111111, 0b11111111, 0b11111111, 0b11111111, */
-	PackBits_Literal(36),
-	0b10000000, 0b00000000, 0b00000000, 0b00000001,
-	0b10001111, 0b00011110, 0b00111100, 0b01111001,
-	0b10001001, 0b00010010, 0b00100100, 0b01001001,
-	0b10001001, 0b00010010, 0b00100100, 0b01001001,
-	0b10001001, 0b00010010, 0b00100100, 0b01001001,
-	0b10001111, 0b00011110, 0b00111100, 0b01111001,
-	0b11000000, 0b00000000, 0b00000000, 0b00000001,
-	0b01010101, 0b01010101, 0b11010101, 0b01010101,
-	0b01111111, 0b11111111, 0b01111111, 0b11111111,
-	PackBits_Repeat(12), 0b00000000, /*
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
-	
-	PackBits_Repeat(76), 0b00000000, /*
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
-	PackBits_Repeat(32), 0b11111111, /*
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111,
-	0b11111111, 0b11111111, 0b11111111, 0b11111111, */
-	PackBits_Literal(1), 0b01111111, 
-	PackBits_Repeat(3), 0b11111111, /*
-	0b01111111, 0b11111111, 0b11111111, 0b11111111, */
-	PackBits_Literal(1), 0b01111111, 
-	PackBits_Repeat(3), 0b11111111, /*
-	0b01111111, 0b11111111, 0b11111111, 0b11111111, */
-	PackBits_Repeat(12), 0b00000000, /*
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000,
-	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
-	PackBits_Literal(29),
-	26, 'G', 'a', 'r', 'r', 'e', 't', 't', '\'', 's', ' ', 
-	'W', 'o', 'r', 'k', 's', 'h', 'o', 'p', ' ', 
-	'S', 'D', ' ', 'D', 'i', 's', 'k', 0
-};
-
-#endif
diff --git a/spi.c b/spi.c
new file mode 100644
index 0000000..e33bcdb
--- /dev/null
+++ b/spi.c
@@ -0,0 +1,129 @@
+#include "spi.h"
+#include "spi_hal.h"
+
+static int _search_lt(char *buf, int stride, int threshold) {
+    for (int i = 1; i < 256; i++) {
+        if (buf[i * stride] < threshold) { return 1; }
+    }
+    return 0;
+}
+
+int _spi_hal_rx8_nops, _spi_hal_tx8_nops;
+int _spi_hal_rx16_nops, _spi_hal_tx16_nops;
+int _spi_hal_rxtx8_nops;
+
+short *_spi_reg_rx16;
+char *_spi_reg_tx16;
+short *_spi_reg_rd16;
+
+int spi_init(int swap) {
+    short buf16[256];
+    char *buf8 = (char*)&buf16;
+
+    for (int i = 0; i < 8; i++) {
+        spi_hal_rx8(SPI_REG_TIMER8, buf8, 256, i);
+        _spi_hal_rx8_nops = i;
+        _spi_hal_tx8_nops = i > 0 ? i - 1 : 0;
+        if (!_search_lt(buf8, 1, 8)) { break; }
+    }
+
+    for (int i = 0; i < 16; i++) {
+        spi_hal_rx16(SPI_REG_TIMER16, buf16, 256, i);
+        _spi_hal_rx16_nops = i;
+        _spi_hal_tx16_nops = i > 0 ? i - 1 : 0;
+        if (!_search_lt(buf8, 2, 8)) { break; }
+    }
+    
+    for (int i = 0; i < 8; i++) {
+        spi_hal_rxtx8(SPI_REG_EMPTY, SPI_REG_TIMER16, buf8, buf8, 256, i);
+        _spi_hal_rxtx8_nops = i;
+        if (!_search_lt(buf8, 1, 8)) { break; }
+    }
+
+    _spi_reg_rx16 = swap ? SPI_REG_RX16S : SPI_REG_RX16;
+    _spi_reg_tx16 = swap ? SPI_REG_TX16S : SPI_REG_TX16;
+    _spi_reg_rd16 = swap ? SPI_REG_RD16S : SPI_REG_RD16;
+    return 0;
+}
+
+void spi_cs(int cs) {
+    if (cs) { SPI_REG_CSR_SET_CS(); }
+    else { SPI_REG_CSR_CLR_CS(); }
+}
+
+char spi_txrx8_slow(char txd) {
+    char rxd = 0;
+    for (int i = 7; i >= 0; i--) {
+        spi_delay(64);
+        SPI_REG_CSR_CLR_SCK();
+        spi_delay(64);
+        SPI_REG_SET_MOSI((txd >> i) & 1);
+        rxd = (rxd << 1) | SPI_REG_CSR_GET_MISO();
+        SPI_REG_CSR_SET_SCK();
+    }
+    spi_delay(64);
+    SPI_REG_CSR_CLR_SCK();
+    return rxd;
+}
+
+char spi_txrx8(char txd) {
+    spi_hal_tx8(SPI_REG_TX8, &txd, 1, _spi_hal_tx8_nops);
+    return *SPI_REG_RD8;
+}
+
+char spi_rxtx8(char txd) {
+    char rxd = *SPI_REG_RD8;
+    spi_hal_tx8(SPI_REG_TX8, &txd, 1, _spi_hal_tx8_nops);
+    return rxd;
+}
+
+#define UNROLL_LENGTH 5
+
+void spi_rx(char txd, char *rxb, unsigned int length) {
+    if (length == 0) { return; } // Return if length 0
+
+    // Word-align rx pointer by transferring 0/1 bytes
+    if ((int)rxb & 1) {
+        *(rxb++) = spi_rxtx8(txd);
+        length--;
+    }
+
+    // Set tx pattern
+    reg_write16(SPI_REG_ST16, smear8to32(txd));
+    
+    // Transfer all but 0-65 bytes
+    for (int i = length >> (UNROLL_LENGTH +1); i > 0; i--) {
+        // Transfer 2^UNROLL_LENGTH words (2 * 2^UNROLL_LENGTH bytes)
+        spi_hal_rx16(_spi_reg_rx16, rxb, UNROLL_LENGTH, _spi_hal_rx16_nops);
+    }
+    
+    // Transfer remaining 1-32 words (2-64 bytes)
+    spi_hal_rx16(_spi_reg_rx16, rxb, length >> 1, _spi_hal_rx16_nops);
+
+    // Transfer remaining byte if any
+    if (length & 1) { *(rxb++) = spi_rxtx8(txd); }
+}
+
+void spi_tx(char *txb, unsigned int length) {
+    if (length == 0) { return; } // Return if length 0
+
+    // Word-align tx pointer by transferring 0/1 bytes
+    if ((int)txb & 1) {
+        spi_rxtx8(*(txb++));
+        length--;
+    }
+
+    // Transfer all but 0-65 bytes
+    for (; length > UNROLL_LENGTH; length -= UNROLL_LENGTH) {
+        spi_hal_tx16(_spi_reg_tx16, txb, UNROLL_LENGTH, _spi_hal_tx16_nops);
+    }
+    
+    // Transfer remaining 1-32 words (2-64 bytes)
+    spi_hal_tx16(_spi_reg_tx16, txb, length >> 1, _spi_hal_tx16_nops);
+
+    // Transfer remaining byte if any
+    if (length & 1) { spi_rxtx8(*(txb++)); }
+}
+
+char spi_rd8() { return *SPI_REG_RD8; }
+short spi_rd16() { return *_spi_reg_rd16; }
diff --git a/spi.h b/spi.h
new file mode 100644
index 0000000..7f4acdf
--- /dev/null
+++ b/spi.h
@@ -0,0 +1,20 @@
+#ifndef _SPI_H
+#define _SPI_H
+
+#include <stddef.h>
+
+int spi_init();
+
+void spi_cs(int cs);
+
+char spi_txrx8_slow(char txd);
+char spi_txrx8(char txd);
+char spi_rxtx8(char txd);
+
+void spi_tx(char *txb, unsigned int length);
+void spi_rx(char txd, char *rxb, unsigned int length);
+
+char spi_rd8();
+short spi_rd16();
+
+#endif
\ No newline at end of file
diff --git a/spi_hal.h b/spi_hal.h
new file mode 100644
index 0000000..ed6686a
--- /dev/null
+++ b/spi_hal.h
@@ -0,0 +1,79 @@
+#ifndef _SPI_HAL_H
+#define _SPI_HAL_H
+
+#pragma parameter spi_delay(__D0)
+extern void spi_delay(char iterations);
+
+#pragma parameter _reg_write8(__A0, __D0, __D1)
+extern void _reg_write8(void *addr, char data, int tmp);
+static inline void reg_write8(void *addr, char data) { _reg_write8(addr, data, 0); }
+
+#pragma parameter _reg_write16(__A0, __D0, __D1)
+extern void _reg_write16(void *addr, short data, int tmp);
+static inline void reg_write16(void *addr, short data) { _reg_write16(addr, data, 0); }
+
+#pragma parameter __D0 smear8to32(__D0)
+extern long smear8to32(char data);
+
+// Read transfer registers
+#define SPI_REG_RX8     ((char*)    0x00000000) // A[01:00]==2'b00, D[31:24]==ret
+#define SPI_REG_RX16    ((short*)   0x00000000) // A[01:00]==2'b00, D[31:16]==ret
+#define SPI_REG_RX16S   ((short*)   0x00000000) // A[01:00]==2'b00, D[31:16]==ret
+#define SPI_REG_RD8     ((char*)    0x00000000) // A[01:00]==2'b00, D[31:24]==ret
+#define SPI_REG_RD16    ((short*)   0x00000000) // A[01:00]==2'b00, D[31:16]==ret
+#define SPI_REG_RD16S   ((short*)   0x00000000) // A[01:00]==2'b00, D[31:16]==ret
+#define SPI_REG_TIMER8  ((char*)    0x00000000) // A[01:00]==2'b00, D[31:24]==ret
+#define SPI_REG_TIMER16 ((short*)   0x00000000) // A[01:00]==2'b00, D[31:16]==ret
+// Write transfer registers
+#define SPI_REG_TX8     ((char*)    0x00000000) // A[07:00]==arg
+#define SPI_REG_TX16    ((char*)    0x00000000) // A[15:00]==arg
+#define SPI_REG_TX16S   ((char*)    0x00000000) // A[05:00]==arg
+#define SPI_REG_ST16    ((char*)    0x00000000) // A[15:00]==arg
+#define SPI_REG_EMPTY   ((char*)    0x00000000)
+// Control/status register (read/write)
+#define SPI_REG_RD_CSR  ((char*)    0x00000000)
+#define SPI_REG_WR_CSR  ((char*)    0x00000000)
+#define SPI_REG_CSR_BIT_nDET    (0)
+#define SPI_REG_CSR_GET_nDET()  ((*SPI_REG_RD_CSR>>SPI_REG_CSR_BIT_nDET) & 1)
+#define SPI_REG_CSR_BIT_MISO    (1)
+#define SPI_REG_CSR_GET_MISO()  ((*SPI_REG_RD_CSR>>SPI_REG_CSR_BIT_MISO) & 1)
+#define SPI_REG_CSR_BIT_SCK     (2)
+#define SPI_REG_CSR_SET_SCK()   reg_write16(SPI_REG_WR_CSR, *SPI_REG_RD_CSR |  (1<<SPI_REG_CSR_BIT_SCK))
+#define SPI_REG_CSR_CLR_SCK()   reg_write16(SPI_REG_WR_CSR, *SPI_REG_RD_CSR & ~(1<<SPI_REG_CSR_BIT_SCK))
+#define SPI_REG_CSR_BIT_CS      (3)
+#define SPI_REG_CSR_SET_CS()    reg_write16(SPI_REG_WR_CSR, *SPI_REG_RD_CSR |  (1<<SPI_REG_CSR_BIT_CS))
+#define SPI_REG_CSR_CLR_CS()    reg_write16(SPI_REG_WR_CSR, *SPI_REG_RD_CSR & ~(1<<SPI_REG_CSR_BIT_CS))
+
+#define SPI_REG_SET_MOSI(x)     reg_write16(SPI_REG_ST16, x ? 0xFFFF : 0x0000)
+
+#pragma parameter _spi_hal_rx8(__A0, __A2, __A4, __D0, __D1, __D2)
+extern void _spi_hal_rx8(void *reg, void *rx, void *tmp, int length, int nops, int tmp2);
+static inline void spi_hal_rx8(void *reg, void *rx, int length, int nops) { 
+    _spi_hal_rx8(reg, rx, 0, length, nops, 0);
+}
+
+#pragma parameter _spi_hal_rx16(__A0, __A2, __A4, __D0, __D1, __D2)
+extern void _spi_hal_rx16(void *reg, void *rx, void *tmp, int length, int nops, int tmp2);
+static inline void spi_hal_rx16(void *reg, void *rx, int length, int nops) { 
+    _spi_hal_rx16(reg, rx, 0, length, nops, 0);
+}
+
+#pragma parameter _spi_hal_tx8(__A0, __A3, __A4, __D0, __D1, __D2)
+extern void _spi_hal_tx8(void *reg, void *tx, void *tmp, int length, int nops, int tmp2);
+static inline void spi_hal_tx8(void *reg, void *tx, int length, int nops) { 
+    _spi_hal_tx8(reg, tx, 0, length, nops, 0);
+}
+
+#pragma parameter _spi_hal_tx16(__A0, __A3, __A4, __D0, __D1, __D2)
+extern void _spi_hal_tx16(void *reg, void *tx, void *tmp, int length, int nops, int tmp2);
+static inline void spi_hal_tx16(void *reg, void *tx, int length, int nops) { 
+    _spi_hal_tx16(reg, tx, 0, length, nops, 0);
+}
+
+#pragma parameter _spi_hal_rxtx8(__A0, __A1, __A2, __A3, __A4, __D0, __D1, __D2)
+extern void _spi_hal_rxtx8(void *reg, void *read, void *rx, void *tx, void *tmp, int length, int nops, int tmp2);
+static inline void spi_hal_rxtx8(void *reg, void *read, void *rx, void *tx, int length, int nops) { 
+    _spi_hal_rxtx8(reg, read, rx, tx, 0, length, nops, 0);
+}
+
+#endif
diff --git a/spi_hal.s b/spi_hal.s
new file mode 100644
index 0000000..870d616
--- /dev/null
+++ b/spi_hal.s
@@ -0,0 +1,49 @@
+.global spi_delay
+.global _reg_write16
+.global _reg_write8
+.global smear8to32
+
+* delay calling convention
+* D0 - iterations
+
+spi_delay:
+    subq.w #1, %D0
+    bne.b spi_delay
+    rts
+
+* reg_write calling convention
+* A0 - address
+* D0 - data (clobbered)
+* D1 - clobbered
+
+_reg_write8:
+    move.l %A0, %D1
+    andi.l #0xFFFFFF00, %D1
+    andi.l #0x000000FF, %D0
+    or %D1, %D0
+    movea %D0, %A0
+    move.l (%A0), %D0
+    rts
+
+_reg_write16:
+    move.l %A0, %D1
+    andi.l #0xFFFF0000, %D1
+    andi.l #0x0000FFFF, %D0
+    or %D1, %D0
+    movea %D0, %A0
+    move.l (%A0), %D0
+    rts
+
+* smear8to32 calling convention
+* D0 - data in/out
+
+smear8to32:
+    andi.l #0xFF, %D0
+    move.l %D0, %D1
+    lsl.w #8, %D1
+    or.w %D1, %D0
+    lsl.w #8, %D1
+    or.w %D1, %D0
+    lsl.w #8, %D1
+    or.w %D1, %D0
+    rts
diff --git a/spi_hal_common.s b/spi_hal_common.s
new file mode 100644
index 0000000..d259512
--- /dev/null
+++ b/spi_hal_common.s
@@ -0,0 +1,98 @@
+* spi calling convention
+* A0 - ROM register
+* A1 - readback address
+* A2 - RX buffer
+* A3 - TX buffer
+* A4 - clobbered
+* D0 - length (clobbered)
+* D1 - nops (clobbered)
+* D2 - clobbered (save SR)
+* D3 - clobbered (save CACR)
+
+.macro spi_call table, maxnops
+    * Limit %D0 (length) to 1-256
+    subq.w #1, %D0
+    andi.l #0xFF, %D0
+    addq.w #1, %D0
+    
+    * Limit %D1 (nops) based on maxnops
+    .if \maxnops == 1
+        andi.l #1, %D1
+    .elseif \maxnops == 3
+        andi.l #3, %D1
+    .elseif \maxnops == 7
+        andi.l #7, %D1
+    .elseif \maxnops == 15
+        andi.l #15, %D1
+    .elseif \maxnops != 0
+        .error
+    .endif
+
+    * Convert length to offset
+    * %D0 = -%D0 (-length)
+    neg.l %D0
+    * %D0 = %D0 + 256 (-length + 256)
+    add.l #256, %D0
+
+    .if \maxnops != 0
+        * Combine nops with offset to get lookup table index
+        * %D1 = %D1 * 4 * 256 (nops * 256)
+        lsl.l #8, %D1
+        * %D0 = %D0 + %D1 (offset + nops*256)
+        or.l %D1, %D0
+    .endif
+    
+    * Get index of entry point from lookup table
+    * %D0 = table[%D0] (table[4*(length+nops*256)])
+    move.l (\table - ., %PC, %D0.w : 4), %D0
+
+    * Save status register and disable interrupts
+    move.w %SR, %D2
+    ori.w #0x0700, %SR
+
+    * Save CACR in %D3
+    movec %CACR, %D3
+
+    * Copy CACR to %D1
+    move.l %D3, %D1
+    * Clear CACR bits:
+    * DE  ('040 enable data cache)          (31)
+    * WA  ('030 write allocate)             (13)
+    * DBE ('030 data burst enable)          (12)
+    * CD  ('030 clear data cache)           (11)
+    * CED ('030 clear entry in data cache)  (10)
+    * FD  ('030 freeze data cache)          (9)
+    * ED  ('030 enable data cache)          (8)
+    andi.l #0x7FFFC0FF, %D1
+    * Set '030 CACR bits:
+    * FD (freeze data cache) (9)
+    ori.w #0x0200, %D1
+    * Move back into CACR
+    movec.l %D1, %CACR
+
+    * Jump to entry point
+    * (table + table[length*4 + nops*4*256])
+    jmp (\table - ., %PC, %D0.l)
+
+    * Return statement for use with parameter checking
+    ret: rts
+.endm
+
+.macro lookup_table base, nbase, stride, n
+    dc.l \nbase - \base
+    dc.l \nbase + \stride - \base
+    dc.l \nbase + \stride+\stride - \base
+    dc.l \nbase + \stride+\stride+\stride - \base
+    .if \n > 0
+    lookup_table \base, \nbase + \stride+\stride+\stride+\stride, \stride, \n-4
+    .endif
+.endm
+
+.macro unroll_table macro, nops, n
+    .rept \n
+        \macro \nops
+    .endr
+    move.w %D2, %SR
+    movec.l %D3, %CACR
+    rts
+.endm
diff --git a/spi_rx16.s b/spi_rx16.s
new file mode 100644
index 0000000..be03345
--- /dev/null
+++ b/spi_rx16.s
@@ -0,0 +1,73 @@
+* spi calling convention
+* A0 - ROM register
+* A1 - readback address
+* A2 - RX buffer
+* A3 - TX buffer
+* A4 - clobbered
+* D0 - length (clobbered)
+* D1 - nops (clobbered)
+
+.global _spi_hal_rx16
+
+.include "spi_hal_common.s"
+
+.macro _spi_hal_rx16_iteration nops
+    move.w (%A0), (%A2)+
+    .rept \nops
+        nop
+    .endr
+.endm
+
+.align 16
+_spi_hal_rx16:
+    spi_call _spi_hal_rx16_lookup, 15
+.align 16
+_spi_hal_rx16_lookup:
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_0,  2,  256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_1,  4,  256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_2,  6,  256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_3,  8,  256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_4,  10, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_5,  12, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_6,  14, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_7,  16, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_8,  18, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_9,  20, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_10, 22, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_11, 24, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_12, 26, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_13, 28, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_14, 30, 256
+    lookup_table _spi_hal_rx16_lookup, _spi_hal_rx16_table_15, 32, 256
+.align 16
+_spi_hal_rx16_table_0:  unroll_table _spi_hal_rx16_iteration, 0, 256
+.align 16
+_spi_hal_rx16_table_1:  unroll_table _spi_hal_rx16_iteration, 1, 256
+.align 16
+_spi_hal_rx16_table_2:  unroll_table _spi_hal_rx16_iteration, 2, 256
+.align 16
+_spi_hal_rx16_table_3:  unroll_table _spi_hal_rx16_iteration, 3, 256
+.align 16
+_spi_hal_rx16_table_4:  unroll_table _spi_hal_rx16_iteration, 4, 256
+.align 16
+_spi_hal_rx16_table_5:  unroll_table _spi_hal_rx16_iteration, 5, 256
+.align 16
+_spi_hal_rx16_table_6:  unroll_table _spi_hal_rx16_iteration, 6, 256
+.align 16
+_spi_hal_rx16_table_7:  unroll_table _spi_hal_rx16_iteration, 7, 256
+.align 16
+_spi_hal_rx16_table_8:  unroll_table _spi_hal_rx16_iteration, 8, 256
+.align 16
+_spi_hal_rx16_table_9:  unroll_table _spi_hal_rx16_iteration, 9, 256
+.align 16
+_spi_hal_rx16_table_10: unroll_table _spi_hal_rx16_iteration, 10, 256
+.align 16
+_spi_hal_rx16_table_11: unroll_table _spi_hal_rx16_iteration, 11, 256
+.align 16
+_spi_hal_rx16_table_12: unroll_table _spi_hal_rx16_iteration, 12, 256
+.align 16
+_spi_hal_rx16_table_13: unroll_table _spi_hal_rx16_iteration, 13, 256
+.align 16
+_spi_hal_rx16_table_14: unroll_table _spi_hal_rx16_iteration, 14, 256
+.align 16
+_spi_hal_rx16_table_15: unroll_table _spi_hal_rx16_iteration, 15, 256
diff --git a/spi_rx8.s b/spi_rx8.s
new file mode 100644
index 0000000..580b5c0
--- /dev/null
+++ b/spi_rx8.s
@@ -0,0 +1,49 @@
+* spi calling convention
+* A0 - ROM register
+* A1 - readback address
+* A2 - RX buffer
+* A3 - TX buffer
+* A4 - clobbered
+* D0 - length (clobbered)
+* D1 - nops (clobbered)
+
+.global _spi_hal_rx8
+
+.include "spi_hal_common.s"
+
+.macro _spi_hal_rx8_iteration nops
+    move.b (%A0), (%A2)+
+    .rept \nops
+        nop
+    .endr
+.endm
+
+.align 16
+_spi_hal_rx8:
+    spi_call _spi_hal_rx8_lookup, 7
+.align 16
+_spi_hal_rx8_lookup:
+    lookup_table _spi_hal_rx8_lookup, _spi_hal_rx8_table_0, 2,  256
+    lookup_table _spi_hal_rx8_lookup, _spi_hal_rx8_table_1, 4,  256
+    lookup_table _spi_hal_rx8_lookup, _spi_hal_rx8_table_2, 6,  256
+    lookup_table _spi_hal_rx8_lookup, _spi_hal_rx8_table_3, 8,  256
+    lookup_table _spi_hal_rx8_lookup, _spi_hal_rx8_table_4, 10, 256
+    lookup_table _spi_hal_rx8_lookup, _spi_hal_rx8_table_5, 12, 256
+    lookup_table _spi_hal_rx8_lookup, _spi_hal_rx8_table_6, 14, 256
+    lookup_table _spi_hal_rx8_lookup, _spi_hal_rx8_table_7, 16, 256
+.align 16
+_spi_hal_rx8_table_0: unroll_table _spi_hal_rx8_iteration, 0, 256
+.align 16
+_spi_hal_rx8_table_1: unroll_table _spi_hal_rx8_iteration, 1, 256
+.align 16
+_spi_hal_rx8_table_2: unroll_table _spi_hal_rx8_iteration, 2, 256
+.align 16
+_spi_hal_rx8_table_3: unroll_table _spi_hal_rx8_iteration, 3, 256
+.align 16
+_spi_hal_rx8_table_4: unroll_table _spi_hal_rx8_iteration, 4, 256
+.align 16
+_spi_hal_rx8_table_5: unroll_table _spi_hal_rx8_iteration, 5, 256
+.align 16
+_spi_hal_rx8_table_6: unroll_table _spi_hal_rx8_iteration, 6, 256
+.align 16
+_spi_hal_rx8_table_7: unroll_table _spi_hal_rx8_iteration, 7, 256
diff --git a/spi_rxtx8.s b/spi_rxtx8.s
new file mode 100644
index 0000000..877c77f
--- /dev/null
+++ b/spi_rxtx8.s
@@ -0,0 +1,62 @@
+* spi calling convention
+* A0 - ROM register
+* A1 - readback address
+* A2 - RX buffer
+* A3 - TX buffer
+* A4 - clobbered
+* D0 - length (clobbered)
+* D1 - nops (clobbered)
+
+* spi single calling convention
+* A0 - ROM register
+* A1 - readback address
+* D0 - data
+* D1 - clobbered
+
+.global _spi_hal_rxtx8
+.global _spi_hal_rxtx8single
+
+.include "spi_hal_common.s"
+
+.macro _spi_hal_rxtx8_iteration nops
+    move.b (%A1), (%A2)+
+    move.b (%A3)+, %D1
+    move.b (%A0, %D1.W), %D1
+    .rept \nops
+    nop
+    .endr
+.endm
+
+.align 16
+_spi_hal_rxtx8:
+    spi_call _spi_hal_rxtx8_lookup, 7
+_spi_hal_rxtx8_single:
+    move.b (%A1), %D0
+    move.b (%A0, %D1.W), %D1
+    rts
+.align 16
+_spi_hal_rxtx8_lookup:
+    lookup_table _spi_hal_rxtx8_lookup, _spi_hal_rxtx8_table_0, 8,  256
+    lookup_table _spi_hal_rxtx8_lookup, _spi_hal_rxtx8_table_1, 10, 256
+    lookup_table _spi_hal_rxtx8_lookup, _spi_hal_rxtx8_table_2, 12, 256
+    lookup_table _spi_hal_rxtx8_lookup, _spi_hal_rxtx8_table_3, 14, 256
+    lookup_table _spi_hal_rxtx8_lookup, _spi_hal_rxtx8_table_4, 16, 256
+    lookup_table _spi_hal_rxtx8_lookup, _spi_hal_rxtx8_table_5, 18, 256
+    lookup_table _spi_hal_rxtx8_lookup, _spi_hal_rxtx8_table_6, 20, 256
+    lookup_table _spi_hal_rxtx8_lookup, _spi_hal_rxtx8_table_7, 22, 256
+.align 16
+_spi_hal_rxtx8_table_0: unroll_table _spi_hal_rxtx8_iteration, 0, 256
+.align 16
+_spi_hal_rxtx8_table_1: unroll_table _spi_hal_rxtx8_iteration, 1, 256
+.align 16
+_spi_hal_rxtx8_table_2: unroll_table _spi_hal_rxtx8_iteration, 2, 256
+.align 16
+_spi_hal_rxtx8_table_3: unroll_table _spi_hal_rxtx8_iteration, 3, 256
+.align 16
+_spi_hal_rxtx8_table_4: unroll_table _spi_hal_rxtx8_iteration, 4, 256
+.align 16
+_spi_hal_rxtx8_table_5: unroll_table _spi_hal_rxtx8_iteration, 5, 256
+.align 16
+_spi_hal_rxtx8_table_6: unroll_table _spi_hal_rxtx8_iteration, 6, 256
+.align 16
+_spi_hal_rxtx8_table_7: unroll_table _spi_hal_rxtx8_iteration, 7, 256
diff --git a/spi_tx16.s b/spi_tx16.s
new file mode 100644
index 0000000..c2c3633
--- /dev/null
+++ b/spi_tx16.s
@@ -0,0 +1,74 @@
+* spi calling convention
+* A0 - ROM register
+* A1 - readback address
+* A2 - RX buffer
+* A3 - TX buffer
+* A4 - clobbered
+* D0 - length (clobbered)
+* D1 - nops (clobbered)
+
+.global _spi_hal_tx16
+
+.include "spi_hal_common.s"
+
+.macro _spi_hal_tx16_iteration nops
+    move.w (%A3)+, %D1
+    move.b (%A0, %D1.W), %D1
+    .rept \nops
+    nop
+    .endr
+.endm
+
+.align 16
+_spi_hal_tx16:
+    spi_call _spi_hal_tx16_lookup, 15
+.align 16
+_spi_hal_tx16_lookup:
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_0,  6,  256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_1,  8,  256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_2,  10, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_3,  12, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_4,  14, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_5,  16, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_6,  18, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_7,  20, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_8,  22, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_9,  24, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_10, 26, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_11, 28, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_12, 30, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_13, 32, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_14, 34, 256
+    lookup_table _spi_hal_tx16_lookup, _spi_hal_tx16_table_15, 36, 256
+.align 16
+_spi_hal_tx16_table_0:  unroll_table _spi_hal_tx16_iteration, 0, 256
+.align 16
+_spi_hal_tx16_table_1:  unroll_table _spi_hal_tx16_iteration, 1, 256
+.align 16
+_spi_hal_tx16_table_2:  unroll_table _spi_hal_tx16_iteration, 2, 256
+.align 16
+_spi_hal_tx16_table_3:  unroll_table _spi_hal_tx16_iteration, 3, 256
+.align 16
+_spi_hal_tx16_table_4:  unroll_table _spi_hal_tx16_iteration, 4, 256
+.align 16
+_spi_hal_tx16_table_5:  unroll_table _spi_hal_tx16_iteration, 5, 256
+.align 16
+_spi_hal_tx16_table_6:  unroll_table _spi_hal_tx16_iteration, 6, 256
+.align 16
+_spi_hal_tx16_table_7:  unroll_table _spi_hal_tx16_iteration, 7, 256
+.align 16
+_spi_hal_tx16_table_8:  unroll_table _spi_hal_tx16_iteration, 8, 256
+.align 16
+_spi_hal_tx16_table_9:  unroll_table _spi_hal_tx16_iteration, 9, 256
+.align 16
+_spi_hal_tx16_table_10: unroll_table _spi_hal_tx16_iteration, 10, 256
+.align 16
+_spi_hal_tx16_table_11: unroll_table _spi_hal_tx16_iteration, 11, 256
+.align 16
+_spi_hal_tx16_table_12: unroll_table _spi_hal_tx16_iteration, 12, 256
+.align 16
+_spi_hal_tx16_table_13: unroll_table _spi_hal_tx16_iteration, 13, 256
+.align 16
+_spi_hal_tx16_table_14: unroll_table _spi_hal_tx16_iteration, 14, 256
+.align 16
+_spi_hal_tx16_table_15: unroll_table _spi_hal_tx16_iteration, 15, 256
diff --git a/spi_tx8.s b/spi_tx8.s
new file mode 100644
index 0000000..84fd0c8
--- /dev/null
+++ b/spi_tx8.s
@@ -0,0 +1,50 @@
+* spi calling convention
+* A0 - ROM register
+* A1 - readback address
+* A2 - RX buffer
+* A3 - TX buffer
+* A4 - clobbered
+* D0 - length (clobbered)
+* D1 - nops (clobbered)
+
+.global _spi_hal_tx8
+
+.include "spi_hal_common.s"
+
+.macro _spi_hal_tx8_iteration nops
+    move.b (%A3)+, %D1
+    move.b (%A0, %D1.W), %D1
+    .rept \nops
+    nop
+    .endr
+.endm
+
+.align 16
+_spi_hal_tx8:
+    spi_call _spi_hal_tx8_lookup, 7
+.align 16
+_spi_hal_tx8_lookup:
+    lookup_table _spi_hal_tx8_lookup, _spi_hal_tx8_table_0, 6,  256
+    lookup_table _spi_hal_tx8_lookup, _spi_hal_tx8_table_1, 8,  256
+    lookup_table _spi_hal_tx8_lookup, _spi_hal_tx8_table_2, 10, 256
+    lookup_table _spi_hal_tx8_lookup, _spi_hal_tx8_table_3, 12, 256
+    lookup_table _spi_hal_tx8_lookup, _spi_hal_tx8_table_4, 14, 256
+    lookup_table _spi_hal_tx8_lookup, _spi_hal_tx8_table_5, 16, 256
+    lookup_table _spi_hal_tx8_lookup, _spi_hal_tx8_table_6, 18, 256
+    lookup_table _spi_hal_tx8_lookup, _spi_hal_tx8_table_7, 20, 256
+.align 16
+_spi_hal_tx8_table_0: unroll_table _spi_hal_tx8_iteration, 0, 256
+.align 16
+_spi_hal_tx8_table_1: unroll_table _spi_hal_tx8_iteration, 1, 256
+.align 16
+_spi_hal_tx8_table_2: unroll_table _spi_hal_tx8_iteration, 2, 256
+.align 16
+_spi_hal_tx8_table_3: unroll_table _spi_hal_tx8_iteration, 3, 256
+.align 16
+_spi_hal_tx8_table_4: unroll_table _spi_hal_tx8_iteration, 4, 256
+.align 16
+_spi_hal_tx8_table_5: unroll_table _spi_hal_tx8_iteration, 5, 256
+.align 16
+_spi_hal_tx8_table_6: unroll_table _spi_hal_tx8_iteration, 6, 256
+.align 16
+_spi_hal_tx8_table_7: unroll_table _spi_hal_tx8_iteration, 7, 256