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Work in progress free firmware substitute
- Subject: Work in progress free firmware substitute
- From: lyricalnanoha@dosius.ath.cx (Steve Nickolas)
- Date: Wed, 3 Mar 2010 15:45:14 +0000 (UTC)
- Newsgroups: comp.sys.apple2
- Organization: Mac GUI
- User-agent: Mac GUI City Usenet Posting
- Xref: g2news1.google.com comp.sys.apple2:14477
This is based on some stuff I did a couple years back in C, and then I
rewrote it in ASM. (A couple short functions are lifted from actual
firmware; it's pretty hard not to copy them though.) It's horribly buggy,
but is a semi-passable replacement for the F8 portion of an Apple ][+ ROM.
Some software actually *works*.
http://usotsuki.hoshinet.org/gameware-0.01.zip
The "black code" is "delay" and "pdl" from SimSystem IIe, and "inno" and
"prno" from the Apple ][ monitor.
The debugger is not present in the code. It's very poorly written and only
supports a minimal amount of mostly documented entry points (I'm not sure
CALL -1184 and CALL -1370 are documented. Both of them work.)
My ultimate goal would be to create a complete firmware substitute for use
with emulators, to be "clean". Prolly futile, but meh. At least I got this
far; 4 years ago when I wrote SDDapple BWOR, I don't think I could have
written this much in 65C02 assembly. (It does make heavy use of 65C02
opcodes, mostly to save space.)
Also - Although the comments say ProDOS-8 2.x does not work, in the last
test, I *was* able to get it to boot successfully.
-uso.