From f7c762e7d7196a94b0f1d0bb5fcc4baa50917bf0 Mon Sep 17 00:00:00 2001
From:  <terence@DESKTOP-IESDRVV.localdomain>
Date: Sat, 12 Dec 2020 23:26:16 -0500
Subject: [PATCH] Add initial firmware for EPROM

---
 Firmware/Driver.lst         |   2 +-
 Firmware/Firmware.asm       | 196 ++++++++++++++++++++++++++++++++++++
 Firmware/Firmware.bin       | Bin 0 -> 1792 bytes
 Firmware/driver_assemble.sh |   8 ++
 4 files changed, 205 insertions(+), 1 deletion(-)
 create mode 100644 Firmware/Firmware.asm
 create mode 100644 Firmware/Firmware.bin

diff --git a/Firmware/Driver.lst b/Firmware/Driver.lst
index 1603b34..966d058 100644
--- a/Firmware/Driver.lst
+++ b/Firmware/Driver.lst
@@ -1,4 +1,4 @@
-ca65 V2.18 - Ubuntu 2.18-1
+ca65 V2.19 - Git 59c58ac
 Main file   : Driver.asm
 Current file: Driver.asm
 
diff --git a/Firmware/Firmware.asm b/Firmware/Firmware.asm
new file mode 100644
index 0000000..0d63fb9
--- /dev/null
+++ b/Firmware/Firmware.asm
@@ -0,0 +1,196 @@
+;ProDOS Zero Page
+Command = $42 ;ProDOS Command
+Unit = $43 ;ProDOS unit (SDDD0000)
+BufferLo = $44
+BufferHi = $45
+BlockLo = $46
+BlockHi = $47
+
+; ProDOS Error Codes
+IOError = $27
+NoDevice = $28
+WriteProtect = $2B
+
+SlotDrive = $50
+InputByte = $c08e
+OutputByte = $c08d
+ReadBlockCommand = $01
+WriteBlockCommand = $02
+NibbleStorage = $1d
+
+ .org STARTSLOT
+;ID bytes for booting and drive detection
+ cpx #$20    ;ID bytes for ProDOS and the
+ cpx #$00    ; Apple Autostart ROM
+ cpx #$03    ;
+ cpx #$3C    ;this one for older II's
+
+;load first two blocks and execute to boot
+Boot:
+ lda     #$01    ;set read command
+ sta     Command
+ 
+ jsr $ff58
+ tsx
+ lda $0100,x
+ asl
+ asl
+ asl
+ asl
+ sta $2b
+ sta Unit 
+ tax
+
+ lda     #$00    ;block 0
+ sta     BlockLo
+ sta     BlockHi
+ sta     BufferLo   ;buffer at $800
+ lda     #$08
+ sta     BufferHi
+ jsr     Driver  ;get the block
+
+; lda     #$00    ;block 1
+; sta     BlockLo
+; sta     BlockHi
+; sta     BufferLo   ;buffer at $A00
+; lda     #$0A
+; sta     BufferHi
+; jsr     Driver   ;get the block
+
+; ldx     #sdrive ;set up for slot n
+ jmp     $801    ;execute the block
+
+;;
+; ProDOS Driver code
+; First check that this is the right drive
+Driver: 
+ ldx Unit
+ lda Command; Check which command is being requested
+ beq GetStatus ;0 = Status command
+ cmp #ReadBlockCommand
+ beq ReadBlock
+ cmp #WriteBlockCommand
+ beq WriteBlock
+ sec ;set carry as we don't support any other commands
+ lda #$53 ;Invalid parameter error
+ rts
+
+; ProDOS Status Command Handler
+GetStatus: 
+ ldx #$ff ;low byte number of blocks 
+ ldy #$ff ;high byte number of blocks
+ lda #$0 ;zero accumulator and clear carry for success
+ clc
+ rts
+
+; ProDOS Read Block Command
+ReadBlock: 
+ lda #ReadBlockCommand
+ jsr SendByte
+ lda BlockLo
+ jsr SendByte
+ lda BlockHi
+ jsr SendByte
+ ldy #$0
+ jsr read256
+ inc BufferHi
+ jsr read256
+ dec BufferHi
+ lda #$0 ;zero accumulator and clear carry for success
+ clc
+ rts
+
+read256: 
+ jsr GetByte
+ sta (BufferLo),y
+ iny
+ bne read256
+ rts 
+ 
+; ProDOS Write Block Command
+WriteBlock:
+ lda #WriteBlockCommand
+ jsr SendByte
+ lda BlockLo
+ jsr SendByte
+ lda BlockHi
+ jsr SendByte
+ ldy #$0
+ jsr write256
+ inc BufferHi
+ jsr write256
+ dec BufferHi
+ lda #$0 ;zero accumulator and clear carry for success
+ clc
+ rts
+
+write256:
+ lda (BufferLo),y
+ jsr SendByte
+ iny
+ bne write256
+ rts
+
+SendByte:
+ pha
+ lsr
+ lsr
+ lsr
+ lsr
+ jsr SendNibble
+ pla
+ jsr SendNibble
+ rts
+
+SendNibble:
+ and #$0F
+ ora #$70 ;Write bit low
+ pha 
+waitWrite: 
+ lda InputByte,x
+ asl ;Second highest bit goes low when ready
+ bmi waitWrite
+ pla
+ sta OutputByte,x
+finishWrite:
+ lda InputByte,x
+ asl
+ bpl finishWrite
+ lda #$FF
+ sta OutputByte,x
+ rts
+
+GetByte:
+ jsr GetNibble
+ asl
+ asl
+ asl
+ asl
+ sta NibbleStorage 
+ jsr GetNibble
+ and #$0f
+ ora NibbleStorage
+ rts
+
+GetNibble:
+ lda #$b0 ;set read flag low
+ sta OutputByte,x
+waitRead:
+ lda InputByte,x
+ bmi waitRead
+ ora #$f0 ;set all flags high
+ sta OutputByte,x
+ pha
+finishRead:
+ lda InputByte,x
+ bpl finishRead
+ pla
+end:
+ rts
+
+.repeat	251-<end
+.byte 0
+.endrepeat
+.byte      0,0     ;0000 blocks = check status
+.byte      3       ;bit 0=read 1=status
+.byte     Driver&$00FF ;low byte of entry
diff --git a/Firmware/Firmware.bin b/Firmware/Firmware.bin
new file mode 100644
index 0000000000000000000000000000000000000000..c8490ff44be24a9470e7687514a74a42c1045d15
GIT binary patch
literal 1792
zcmeIyJxjwt0LJm8MW{t+N0&m@B9sme4o-bX+*};9+0ieNQ4cp4p$HYuNmrrJ+#Ppz
z({GT;Iis{gyhn2+5lKYIW}wGG{)PT{pn(%uK{Ys}w%2n`qo;*s*Y)G=dHs88c_VM^
z4QS09IvxMmuHE(Ly>Mq`hs{+b+&`cv?rk)SsI}`-+qw4VBOGIW%q-{3e;evU4)NMq
z`d5SJmv@&|zIOy2iMz*vevNK&q#tMQPxZ%bH@43wi_2xbyPn=$EOBeDX{4{N^Xh;8
z-j=?!8(S@xK71A3&3347_*!!_b*&$tYA5)$pB4HU{0x2uKZBncKTG`Cj-VrP2R}>s
znf9}MKQn$-uAdkBIs6=c4nK#V8$VC{*^ZziaR)z7`MLJ<d_OmSUansh`UU&~egVIL
zUl_kg{MnA6BXI}6Ncn~Ki+sN@eo?Mp7WyUp5`GE4gkKuJO#Io7pd)byzfAe1_RD;~
yG=BN-FZ2IT74EOFzry|s`z!3P%>F9bKid&>B<`@kO6{-o{wjZeW%gHp+5ZDhDBLvw

literal 0
HcmV?d00001

diff --git a/Firmware/driver_assemble.sh b/Firmware/driver_assemble.sh
index 42f9ba3..ddb9fac 100755
--- a/Firmware/driver_assemble.sh
+++ b/Firmware/driver_assemble.sh
@@ -1,3 +1,11 @@
 #!/bin/sh
 ca65 Driver.asm --listing Driver.lst
 ld65 Driver.o -o Driver.bin -t none
+ca65 Firmware.asm -D STARTSLOT=\$c100 -o Slot1.o
+ca65 Firmware.asm -D STARTSLOT=\$c200 -o Slot2.o
+ca65 Firmware.asm -D STARTSLOT=\$c300 -o Slot3.o
+ca65 Firmware.asm -D STARTSLOT=\$c400 -o Slot4.o
+ca65 Firmware.asm -D STARTSLOT=\$c500 -o Slot5.o
+ca65 Firmware.asm -D STARTSLOT=\$c600 -o Slot6.o
+ca65 Firmware.asm -D STARTSLOT=\$c700 -o Slot7.o
+ld65 Slot1.o Slot2.o Slot3.o Slot4.o Slot6.o Slot6.o Slot7.o -o Firmware.bin -t none