Using the Debugger on Other Games

From: ed@iitmax.acc.iit.edu (Ed Federmeyer)
Newsgroups: rec.games.video.classic
Subject: Activision's 2600 Development Station!
Date: 21 Mar 1995 20:56:16 -0600
Organization: Illinois Institute of Technology, Chicago
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In article <3kmsu2$kn7@news.primenet.com> krishna@primenet.com (Glenn Saunders) writes:
>The mortal Scott Butler wrote:
>: It'd be interesting to try to use the emulator as the basis for a new, 
>: PC-based development platform for the 2600. I'd be very interested in 
>: developing 2600 games, if there were a good PC-based development 
>: environment around....
>
>You could use a 6502 cross compiler and download code to the Starpath 
>Supercharger.  That's what I'll encourage when the Starpath CD is released.
>
>And you'll have 6K RAM to work with rather than just the standard 4K ROM 
>and you can write multiloaders that way ;)

I finally found a copy of the 2600 action pack in the Chicagoland
area:  Babages in the North Riverside Mall to be exact.  This is a
seriously cool program!

After playing with it a bit I've found the following:

1)  You can copy 2600emu.exe to debug_x.exe (for example).  Use a HEX
editor on debug.exe to change "PITFALL.BIN" to "DEBUG_X.BIN" (again,
for example) Create a new program icon in Windows to run the new
debug_x.exe.

Now, when you run the debug_x.exe, It will give you the "debug"
pulldown menu, and load DEBUG_X.BIN instead of PITFALL.BIN.

Note:  If there is an easier way to load your own binary image instead
of PITFALL.BIN, please let me know!  My Debug/Open Cart Image...
pulldown menu doesn't do anything!

2)  To create debug_x.bin, use your favorite 6502 cross assembler to
assemble your test-2600 code.  You might need a utility of some kind
to convert the OBJECT file produced by the assembler into a raw BINARY
image, suitable for burning into a 4K EPROM. (This kind of utility
would probably come with an EPROM burner, but maybe there is something
out there you can use???)  Once you have a 4Kb EPROM image, copy it
four times!!!  Ie:  COPY /B test.bin + test.bin + test.bin + test.bin
debug_x.bin (Notice that all the .BIN files that come with the program
are 16K!)

Now you can step through your code, set breakpoints, etc.

When you run your debug_x.exe, it will create a debug_x.ini with some
minimal default values.  You can look at the other *.ini files to get
an idea of the other setup values you can play with.

I sure wish I had this when I was developing SoundX and Edtris 2600!!!

Good Luck, and have fun!
Ed Federmeyer