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 to convert and add/update to a SOS.DRIVER file:

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. Note 'add' will check to see if the drivername already exists, and then only add if it does not. Once a driver exists in a SOS.DRIVER file, then the 'update' command can be used.

python 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 A3Driverutil.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%