Re: Redesigning a new PROM for //e and //c hardware

[BLuRry <brendan.robert@gmail.com>]

On Tuesday, November 6, 2012 10:46:43 PM UTC-6, mspa...@gemsi.com wrote:
> On Monday, November 5, 2012 4:23:34 AM UTC-8, Benoit0123 wrote:
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> > My asking is for the existence of a project which goal is to rewrite the
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> > PROM content, by "refactoring" Applesoft code so that this code could
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> > benefit for a potential enhanced CPU within the host (either CMOS 65C02 or a
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> > 65802).
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> > The code space reduction could benefit for implementing more features for
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> > the monitor or for Applesoft itself.
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> The debug ROM is available out there somewhere. I found a copy, but I'm not sure where at this point. 
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> I was undertaking a project to make the IIe rom do proper disassembly of  65C02 code. I mostly succeeded, but finding the room was quite an exercise. I had to replace the slot-3 check, and do some fancy vectoring. In the enhanced IIe ROM the disassembler is scattered all over. 
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> That was the second half of the project. The first half was to put several of the Beagle Basic routines in ROM to replace the cassette port routines. I have the Else, Tone, Swap, and a Repeat Until (which was not Beagle Basic), and I converted USR() to readkey to save having to peek whatever that was. There was also enough room to have Timer (or Wait) but then I had to sacrifice Flash to get a spare token. 
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> The changes to the token lookup table broke Program Writer,  but GPLE still seemed to work.

The ][db rom is bundled with Jace and you can enable it from the computer options screen (you can in fact do this without rebooting or restarting -- the effect is usually seamless but sometimes you might crash to the monitor because of it)

The disassembly looks almost 1:1 the same as the //gs monitor.

-B