Apple II Programmer's Aid ROM

From: Mike Ford <mikeford_at_socal.rr.com>
Date: Thu Oct 31 03:35:01 2002

>On Tue, 29 Oct 2002, Mike Ford wrote:
>
>> Someplace in my office I have a old program by Laser Systems that
>> reads the rom and makes a "clean" commented disassembly listing of
>> it. Randy Hyde wrote it as a kind of exercise for his disassembler,
>> so its pretty complete as I remember with proper variable names etc.
>> Apple didn't let it stay long on the market though.
>
>What kind of "comments" can it make on the disassembly??
>
>; loads the Accumulator with $#00
>; jumps to location $0800

Randy Hyde liked tools, and LISA, the Laser Interactive Symbolic
Assembler, was his favorite to mess with, so when he added
disassembly to it, he made it so that you could quickly go back and
forth between source code and binary files, with all the comments etc
preserved. How I think it worked was to have 3 files, Source, binary,
and essentially all the text you need to go from binary back to
source. Over a LONG period of time Randy made his own version of the
ROM source files, and made them as accurate as he could using the
same subroutine names and variables as Apple used internally (that he
could find out). Randy's version of the source files may well have
been better and more accurately documented than what Apple had
internally.

He knew he could never get away with selling a full commented etc
listing of the Roms, but figured selling a program that would
disassemble them on the owners own machine and print out the results
with comments etc. would be OK. Apple didn't see it that way.
Received on Thu Oct 31 2002 - 03:35:01 GMT