Open SvOlli opened 8 months ago
That's the 800kB format, right? Making a disk image should be easy as IIRC it's just the same as the later Macintosh 800kB format, but they'll need a whole new set of disk access routines and I'm still burnt out from doing the Apple II routines! If you have any pointers to example code that'll help...
SmartPort access it easy:
; Define SmartPort register addresses
SMARTPORT_COMMAND = $C0E0
SMARTPORT_STATUS = $C0E1
SMARTPORT_DATA = $C0E2
; Command definitions
SMARTPORT_CMD_READ = $02
SMARTPORT_CMD_WRITE = $03
; Buffer for data transfer
BUFFER = $8000
; Initialize the SmartPort
INIT_SMARTPORT:
LDA #$00
STA SMARTPORT_COMMAND ; Reset the SmartPort
RTS
; Send a command to the SmartPort
SEND_COMMAND:
LDX #$00
STX SMARTPORT_STATUS ; Clear status
LDA #SMARTPORT_CMD_READ ; Load command (change to WRITE for write operation)
STA SMARTPORT_COMMAND ; Send command
RTS
; Read data from the SmartPort
READ_DATA:
LDY #$00
READ_LOOP:
LDA SMARTPORT_STATUS
BPL READ_LOOP ; Wait until data is ready
LDA SMARTPORT_DATA ; Read data byte
STA BUFFER, Y ; Store in buffer
INY
CPY #$100 ; Assume 256 bytes to read
BNE READ_LOOP
RTS
; Write data to the SmartPort
WRITE_DATA:
LDY #$00
WRITE_LOOP:
LDA BUFFER, Y ; Load data byte from buffer
STA SMARTPORT_DATA ; Write to SmartPort
INY
CPY #$100 ; Assume 256 bytes to write
BNE WRITE_LOOP
RTS
Any progress? I guess adding more drives support should be easy. For example S6 D2 (5.25"), S5 D1, D2 (3.5"), S7 D1, D2 (HDD or another disk type).
I haven't actually touched it! Is 800kB disk access always through SmartPort or does it use a software-defined interface like the Apple II interface?
The original one is just like Apple II interface, but designed for higher capacity, mostly in ProDOS: https://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Interface%20Cards/Disk%20Drive%20Controllers/Apple%20II%203.5%20Disk%20Controller%20Card/Manuals/Apple%203.5%20Disk%20Controller%20Card%20-%20Owner's%20Guide.pdf
And there are modern implementations like:
https://wiki.reactivemicro.com/Apple_II_3.5_Disk_Controller_Card https://www.bigmessowires.com/yellowstone (not only for FDDs) https://www.a2heaven.com/webshop/resources/pdf_document/18/8f/a.pdf - one of many A2Heaven controllers that supports high-capacity devices, with smartport compatibility
https://en.wikipedia.org/wiki/SuperDrive - It says in 1988 1.44 MB FDDs were introduced for Apple IIe, then in 1991 the controller...
With the Apple II GS and the Apple II C plus, there are two machines capable of running CP/M 65, but can't due to a different disk format (3.5" instead of 5.25").
(And I'd really like to see CP/M 65 running on my real 2gs instead of just in an emulator.)