A3Driverutil

Python program to convert o65 relocatable binary files for use as Apple /// drivers, plus support for adding/updating and removing drivers from the sos.driver file.

The normal procedure for assembling Apple /// drivers is to load the assembler source file into either an emulator or real Apple II or /// computer. And then use the Pascal assembler to assemble and create the required relocatable PCD object file that the Apple /// System Utilities SCP accepts. I bumped into the o65 relocatable binary format while looking around the internet and then noticed that the ca65 assembler includes support for this. I wondered if this could be used and converted for use in driver development.

The spec for the o65 file is available here, plus detail on the usages, etc. : http://6502.org/users/andre/o65/

I've been trying to learn python more, so this seemed like a good excuse to delve into it a bit more. The resultant program has expanded quite a bit on the original idea, and its added a bit of scp functionality to it, eg list, add, delete, update and extract drivers from a SOS.DRIVER file.

Usage:

The ca65 source file needs the comment in the 'TEXT' segment, and the code in the 'DATA' segment. An example skeleton source file is shown below:

        .setcpu "6502"
        .reloc
;
;driver comment field
;this is put in the TEXT segment so we can get the length and output it ok
;
        .segment "TEXT"
        .word   $FFFF               ;Comment follows..
        .word   12                  ;12 bytes long
        .byte   "Test Driver."

;
;Driver code part
;this is put in the DATA segement
;
           
        .segment "DATA"
DIB:    .word   0000                            ; link
        .word   START                           ; entry point
        .byte   05                              ; name len
        .byte   ".TEST          "               ; device name

........rest of the code

        .endproc

Then we assemble and link this with ca65 and ld65 using the Apple3_o65.cfg file (see src folder)

ca65.exe test.s -l test.lst
ld65.exe test.o -o test.o65 -C Apple3_o65.cfg

once we have the binary, then we can convert it and add to an existing SOS.DRIVER file

python -f A3Driverutil.py add test.o65 SOS.DRIVER

Then we can use the disk util of choice to add to a dsk image and run in an emulator or a real machine.

I have used a windows batch file to automate this process to enable quick driver testing, example of mine is shown here:

@REM Driver make/update
@REM Variables
SET FILENAME=grafix
SET DISKIMAGE=C:\Storage\Projects\o65\batchtest\grafixtest.dsk

@REM assemble and link source file
ca65.exe %FILENAME%.s -l %FILENAME%.lst
ld65.exe %FILENAME%.o -o %FILENAME%.o65 -C Apple3_o65.cfg

@REM extract existing SOS.DRIVER file from disk image
java -jar ac.jar -g %DISKIMAGE% SOS.DRIVER > SOS.DRIVER#0c0000

@REM convert the o65 and update existing driver in the SOS.DRIVER file
C:\python27\python.exe o65convert0.5.py update %FILENAME%.o65 SOS.DRIVER#0c0000

@REM delete and then add updated SOS.DRIVER file to the disk image
java -jar ac.jar -d %DISKIMAGE% SOS.DRIVER
java -jar ac.jar -p %DISKIMAGE% SOS.DRIVER SOS $0000 < SOS.DRIVER#0c0000

@REM run the disk image in 
C:\Storage\_emu\Mess\mess.exe apple3 -rompath C:\Storage\_emu\Mess\roms -skip_gameinfo -resolution 640x480 -window -nothrottle -flop1 %DISKIMAGE%