AppleWin/firmware/HDD/hddrvr.a65
2021-11-11 21:24:41 +00:00

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;AppleWin : An Apple //e emulator for Windows
;
;Copyright (C) 1994-1996, Michael O'Brien
;Copyright (C) 1999-2001, Oliver Schmidt
;Copyright (C) 2002-2005, Tom Charlesworth
;Copyright (C) 2006-2012, Tom Charlesworth, Michael Pohoreski
;
;AppleWin is free software; you can redistribute it and/or modify
;it under the terms of the GNU General Public License as published by
;the Free Software Foundation; either version 2 of the License, or
;(at your option) any later version.
;
;AppleWin is distributed in the hope that it will be useful,
;but WITHOUT ANY WARRANTY; without even the implied warranty of
;MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;GNU General Public License for more details.
;
;You should have received a copy of the GNU General Public License
;along with AppleWin; if not, write to the Free Software
;Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
;
; Description: Firmware for harddisk card
;
; Author: Copyright (c) 2005, Robert Hoem
;
; Modified by Tom Charlesworth:
; . Updated so it can be assembled by ACME 0.97
; . Fixed so that ProDOS entrypoint is $c70a (26 Dev 2007) (Bug #12723)
; . Modified to support Apple Oasis' entrypoint: $c761 (8 Sept 2012) (Feature #5557)
; . Added support for SmartPort entrypoint (20 Oct 2012)
; - EG. "Prince of Persia (Original 3.5 floppy for IIc+).2mg"
; . GH#370 (Robert Hoem, 27 Oct 2016):
; . Added a check against open-apple during boot to route boot to slot 6
; . This happens after the first two blocks are loaded from the HD.
; . GH#319: SmartPort return address wrong when crossing page
; . GH#996: Make code slot-independent (so HDD controller card can go into any slot)
; . Moved the 512-byte block read into AppleWin's HDD emulation (to mirror the block write command)
; TODO:
; . Remove support for Entrypoint_Cs46 (old AppleWin) & Entrypoint_Cs61 (Apple Oasis)
; - provide a utility to convert these to use Entrypoint_ProDOS
; . Check SmartPort: Is it OK to trash Y and $42,..,$47 ?
;
!cpu 6502 ; Compatible with all Apple2's
!to "hddrvr.bin", plain
!sl "hddrvr.labels"
; constants
hd_execute = $c080
hd_status = $c081 ; b7=busy, b0=error
hd_command = $c082
hd_unitnum = $c083
hd_memblock = $c084
hd_diskblock = $c086
;hd_nextbyte = $c088 ; legacy read-only port (still supported by AppleWin)
; Notes on accesses to I/O registers:
; . ROR ABS16,X and ROL ABS16,X - only used for $C081+s*$10 STATUS register:
; 6502: double read (old data), write (old data), write (new data). The writes are harmless as writes to STATUS are ignored.
; 65C02: double read (old data), write (new data). The write is harmless as writes to STATUS are ignored.
; . STA ABS16,X does a false-read. This is harmless for writable I/O registers, since the false-read has no side effect.
command = $42
unitnum = $43
memblock = $44
diskblock = $46
slot6 = $C600
OS = $0801
BUTTON0 = $C061
;======================================
!zone code
*= $0000 ; org $0000 - position-independent code, so doesn't matter (but the other fixed org positions need to be on the same page)
; The Autoboot rom will call this.
; This is also the entry point for such things as IN#7 and PR#7
start
; Autoboot and ProDOS look at the following few opcodes to detect block devices
; NB. $Cn07 should be $00 for a SmartPort Interface, but changing this means that it won't autoboot on ][, ][+ and unenhanced IIe.
; . ref: http://www.1000bit.it/support/manuali/apple/technotes/udsk/tn.udsk.2.html
lda #$20
lda #$00
lda #$03
lda #$3C
bne Bootstrap
Entrypoint_ProDOS ; $Cn0A - ProDOS entrypoint
sec
bcs Entrypoint
Entrypoint_SmartPort ; $Cn0D - SmartPort entrypoint
clc
Entrypoint ; $Cn0E - entrypoint?
bcs GetSlotInX ; C=1: GetSlotInX -> cmdproc
; C=0: fall through to SmartPort...
;======================================
; TODO: Is it OK to trash Y and $42,..,$47 ?
; Pre: C=0, X = Slot# << 4
SmartPort ; SmartPort -> GetSlotInX -> cmdproc
pla
sta $46
adc #3 ; Pre: C=0, Post: C=0 or 1
tay
pla
sta $47 ; ($46) = &cmd_hdr
adc #0
pha
tya
pha ; (sp).w += 3
ldy #1
lda ($46),y ; cmd
sta $42
iny
lda ($46),y ; param_l
sta $45
iny
lda ($46),y ; param_h
sta $46
ldy #1 ; skip paramLength (assume it's #$03)
lda ($45),y ; unit
sta $43
iny
lda ($45),y ; memblock_l
sta $44
iny
lda ($45),y ; memblock_h
pha
iny
lda ($45),y ; diskblock_l
pha
iny
bne SmartPort2
;======================================
; 2 unused bytes
@checkCs46
*= $0046 ; org $0046
!warn "Cs46 padding = ", * - @checkCs46
Entrypoint_Cs46 ; Old f/w 'cmdproc' entrypoint
; Keep this for any DOSMaster HDD images created with old AppleWin HDD f/w.
; DOSMaster hardcodes the entrypoint addr into its bootstrapping code:
; - So DOSMaster images are tied to the HDD's controller's f/w
sec
bcs Entrypoint ; or directly to GetSlotInX
;======================================
Bootstrap
; Lets check to see if there's an image ready
; Slot n, disk 1
clc
bcc GetSlotInX ; Post: X = Slot# << 4
Bootstrap2
lda #$00
sta hd_unitnum,x ; b7=0 => disk 1
sta hd_command,x
lda hd_execute,x
ror hd_status,x ; Post: C=0 or 1
bcc hdboot
; no image ready, boot diskette image instead
BootSlot6
jmp slot6
;======================================
; 2 unused bytes
@checkCs61
*= $0061 ; org $0061
!warn "Cs61 padding = ", * - @checkCs61
Entrypoint_Cs61 ; Apple Oasis HDD controller entrypoint
; Keep this for any DOSMaster HDD images created with Apple Oasis HDD f/w.
; DOSMaster hardcodes the entrypoint addr into its bootstrapping code:
; - So DOSMaster images are tied to the HDD's controller's f/w
sec
bcs Entrypoint ; or directly to GetSlotInX
;======================================
; image ready. Lets boot from it.
; we want to load block 1 from disk 1 to $800 then jump there
; Pre: X = Slot# << 4
; C = 0
hdboot
lda #$0
sta unitnum ; b7=0 => disk 1
sta memblock
sta diskblock
sta diskblock+1
lda #$8
sta memblock+1
lda #$1
sta command
bne cmdproc
hdboot2
bcs BootSlot6
bit BUTTON0 ; button 0 pressed?
bmi BootSlot6
; Pre: X = Slot# << 4
jmp OS
;======================================
SmartPort2
lda ($45),y ; diskblock_h
sta $47
pla
sta $46
pla
sta $45
sec
; fall through...
;======================================
; Pre:
; C=0 => via Bootstrap
; C=1 => via Entrypoint / SmartPort2
; Post:
; X = Slot# << 4
GetSlotInX
php
sei ; disable ints, in case an int handler races our $0000/RTS and stack accesses!
; NB. need RAM that's guaranteed to be both read & writeable:
; . can't use $0200-$BFFF, due to eg. RAMRD=0/RAMWRT=1 combination
; . can't use LC as ROM might be enabled.
; So use ZP (specifically $0000) as whatever the state of ALTZP, both read & write will be to the same physical memory location.
lda $00 ; save $00
ldx #$60 ; opcode RTS
stx $00
jsr $0000 ; RTS immediately (NB. can't use $FF58, since LC RAM may be switched in)
sta $00 ; restore $00
tsx
lda $0100,x ; $Cn
asl
asl
asl
asl
tax ; X=$n0
plp ; + restore int status
bcc Bootstrap2
; otherwise fall through for Entrypoint / SmartPort...
;--------------------------------------
; entry point for ProDOS' block driver
; simple really. Copy the command from $42..$47
; to our I/O ports then execute command
; Pre:
; C=0 => via Bootstrap (hdboot)
; C=1 => via GetSlotInX (eg. Entrypoint / SmartPort2)
; X = Slot# << 4
; Post:
; C = hd_status.b0
; A = result of hd_execute
; X = Slot# << 4
cmdproc
php
lda command
sta hd_command,x
lda unitnum
sta hd_unitnum,x
lda memblock
sta hd_memblock,x
lda memblock+1
sta hd_memblock+1,x
lda diskblock
sta hd_diskblock,x
lda diskblock+1
sta hd_diskblock+1,x
lda hd_execute,x ; A = result of hd_execute (NB. instantaneous 512 byte r/w!)
- rol hd_status,x ; b7=busy doing DMA?
bcs -
plp ; restore C from start of cmdproc
bcs done
ror hd_status,x ; Post: C=0 or 1
lda #0
beq hdboot2
done
ror hd_status,x ; Post: C=0 or 1
rts
;======================================
; 33 unused bytes
!zone data
; $CsFE = status bits (BAP p7-14)
; 7 = medium is removable
; 6 = device is interruptable
; 5-4 = number of volumes (0..3 means 1..4)
; 3 = device supports Format call
; 2 = device can be written to
; 1 = device can be read from (must be 1)
; 0 = device status can be read (must be 1)
; $C7 = Removable, Interruptable, #Volumes=1, Supports write/read/status
; $D7 = Removable, Interruptable, #Volumes=2, Supports write/read/status
; $BF = Removable, Interruptable, #Volumes=4, Supports format/write/read/status (KEGS / IIGS)
; datablock. This starts near the end of the firmware (at offset $FC)
;; data
@checkCsFC
*= $00FC ; org $00FC
!warn "CsFC padding = ", * - @checkCsFC
!word $7fff ; how many blocks are on the device.
!byte $D7 ; specifics about the device (number of drives, read/write/format capability, etc)
!byte <Entrypoint_ProDOS ; entry point offset for ProDOS (must be $0a)