[Coco] Portal-9 disassembler

Bob Devries bdevries at gil.com.au
Mon Dec 27 18:31:34 EST 2004

Roger that sounds like magic.

Would that I had it yonks ago when I was trying to add things to a number of 
utility programmes that were for example, hard coded for single sided 
drives, or 600bd printer. SIGH.
Regards, Bob Devries. Dalby, Queensland, Australia.
Faith isn't faith until it's all you're holding on to.

----- Original Message ----- 
From: "Roger Taylor" <rtaylor at bayou.com>
To: <coco at maltedmedia.com>
Sent: Tuesday, December 28, 2004 8:15 AM
Subject: [Coco] Portal-9 disassembler

>I am starting on the disassembler tool for Portal-9 tonight.  What I'll be 
>aiming for is the ability to start a project, load in any binary CoCo 
>binary as a component, click Unbuild, and an .asm file will pop up in it's 
>own window.  If you then tag the .asm file as assemblable, a Build of the 
>same project will produce the binary again.  The new binary won't overwrite 
>the original one since project files are kept in one directory while the 
>output files are kept in another one.
> A grid will be used for tweaking subsequent unbuilds.  The grid will look 
> similar to a spreadsheet layout and let you define where opcodes and data 
> are, the starting address for execution, etc.  The disassembler will 
> follow the code's branches and jumps to help automatically separate code 
> and data.  You'll be able to give predefined label names to certain 
> addresses, so the next unbuild won't automatically assume something like 
> L000100 for an address if it's already defined.  So, a disassemble session 
> will eventually turn into two files; the original binary and the tweaker 
> file (grid).  Everything is saved as the project automatically so you can 
> work on it again another day, or whatever.
> The goal is to let novice and experts both take all of the old CoCo games 
> and programs out there, convert them back to source code, and use Portal-9 
> to rebuild the programs.  Ofcourse, you'll be able to do what you want 
> once the program is in source code form.
> I think a typical session for taking an old popular game, and rewriting 
> it, etc. would be:
> 1) create project (like Pitfall 2005)
> 2) open binary component (like PITFALL.ROM)
> 3) click Unbuild
> 4) observe grid and reports therein, make changes where needed
> 5) observe the produced .asm file (pops up in it's own window)
> 6) repeat #3 until no mysteries are reported about the original binary or 
> the produced source code looks promising
> -- 
> Roger Taylor
> -- 
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