Re: COMMODORE ROM PROJECT

From: Gábor Lénárt <lgb_at_lgb.hu>
Date: Fri, 3 Feb 2012 08:16:58 +0100
Message-ID: <20120203071658.GA31654@vega.lgb.hu>
Hi Ed, Ruud, others! :)


On Fri, Feb 03, 2012 at 07:28:32AM +0100, Baltissen, GJPAA (Ruud) wrote:
> Hallo Ed,
>  
> 
> Some questions:
> - Is there enough room left in the ROM for those goodies? 

Hmm, some may sacrifice the tape routines (well I wouldn't use tap ever
again - some may won't agree with me, for sure ...), so you'll have some
space then to "play".

I just mention it because AFAIK C64-DTV does this; it has got a C64 kernal
but tape routines are removed (and replaced routine loads from the flash,
even with autoboot stuff called "INTRO" from the flash). So it should be a
similar issue what Ed wanted to do, so it can help to get ideas as well,
even if it's not directly usable for a stock C64 of course.

Information:

http://picobay.com/dtv_wiki/index.php?title=DTV2_Kernal_disassembly

It can give some hints how kernal was modified for the DTV, maybe it is
helpful for custom modification for a non-DTV project as well!

Btw it'd be interesting to have a "stock" C64 with some kind of CF/SD etc
card interfaced with (not through IEC though, speed etc, sd2iec can help if
eic is a must); so then DTV's kernal is even much more valuable to try to
use its internals (but not save on dtv ....), filesystem, compression, etc,
I guess only the access of the content on flash, and addressing (dtv uses an
emulated cpu feature to implement MMU, also maybe DMA) should be modified
for the "new environment, and removing user port based madnesses from the
kernal used there :) Which is removed by DTV owners as well anyway, since
then it can be used for other purposes, maybe kernal patchers for DTV are
helpfull to study as well!!!

http://picobay.com/dtv_wiki/index.php?title=Kernalpatcher

> - Are there sources available at all? I do have some, partly commented,
> but for my own assembler.

I guess it's a bit overkill to have a compilable (and working!) source of
the kernal just to recompile it :) Some modifications are simply done by
patching the binary, of course with keeping one eye on the disassembly list,
but not with full recompiling.


> - Which brings me to this one: what assembler should be the base for the
> sources?
> 
> 
> -- 
>      ___  
>     / __|__ 
>    / /  |_/     Groetjes, Ruud 
>    \ \__|_\ 
>     \___|       http://www.Baltissen.org 
> 

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Received on 2012-02-03 08:00:03

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