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OS ROM FastChip source code released by Charles W. Marslett

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Hi together!


Charles W. Marslett has released the FastChip source code, the rewritten ATARI Floating Point ROM routines!!!


I am speechless and so lucky, that a pictues says more than thounds words:




Charles, in the name of the community, thank you so much for your work, your contribution, your help and so much more. We are really deep in your obligation!


More from Charles:





Edited by luckybuck
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And thank you luckybuck for dropping goodies like these in our laps, it's as if Charles Marslett has given us the keys to the candy factory himself. It's most appreciated here.

Right off I find one horrible mistake in the source code offered however - it's so bad it won't work at all if that particular section of bad code is run. How it got to be called version C would be a nice story to hear indeed. But my main interest all along is the FastChip.rom code as it exists in the wild so to speak. Omnimon has it and so does the UltraSpeed Plus OS offered by Bob Puff at CSS. I just happened to notice that between these two versions there is one byte different. Bob spotted a mistake and fixed it in his offering. Both of these offerings carry a 1984 copyright notice within the assembled code itself and the source code posted above is clearly dated 1981 while it doesn't have any notice in the result code at all. They clearly are different then.

Then I wonder how far off the 84 version is from the 81 version. And to this end I start altering the above source code to produce the 84 version of the FastChip.rom code as found in the wild. I offer the results hoping that those that actually understand the finer points of floating point math can have a look and determine if this is indeed the better way to do it. Perhaps improvements are also possible?

So we have the above source code cleaned up a touch to make it easier to read, we have a listed altered 84 version with line numbers much as the above source code has ('ENTER' this), we have the same in a tokenized .m65 version ready to 'LOAD' and assemble, we have the FastChip.rom itself as fixed by Bob Puff, and finally we have a full assembly report. It was some work getting it to fly right.

All lines altered by me will contain a semi-colon followed immediately by a star - ;* Search for that character combo and find only the lines altered by me, the rest of it is as posted above originally. Large sections are unchanged, some parts are a nightmare to follow with all the changes done - it is what it is.

You will have troubles assembling the original code as it doesn't lay down in a contiguous block. As such, file header strippers will not strip stepped over file header blocks of rom code which makes the burning of such eprom code a bit troublesome until you fill in the spaces yourself somehow. Absolutely no sense in posting broken code of the original as it needs fixed first.



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@1050: Wow! Thank you so much. Charles told me, that due to some data disk damages he had, the version was fixed. Will dig into that later (very later), because 1st I would like to finish the source code page on the AtariWiki. If we have all source codes of all languages, the new Atari Age can begin. The fast chip issue would then be a major topic. As we have seen in November with Bill Wilkinson, we really have to hurry...

May I put your changes in the AtariWiki? Please let me know, whether with full name, nickname or none of both.


@tebe: Maybe I am just too stupied, but what path? I can't see anything regarding fastchip under your given address above.

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Thanks flashjazzcat, so we now have proof, I am stupied or it is just again too late at night... ;-)


Great! Out of this the read me:


These are the files provided in this
ARChive of the FASCHIP by Charles

MAC/65 Tokenized source. Load the
header file, and assemble from it.

Object file produced from above
files, when assembled at $D800.

Original AMAC source file (LISTed

MAC/65 Tokenized source for a
program to load D1:FASTFP.OBJ into
the RAM under the OS in XL/XE

Original AMAC source for above.

Original document file listing the
routines contained in the faschip.

This file.


Yes, indeed I will enjoy this. Further, another good thing for the Wiki. :-)))

Double joy! :-))

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