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|    comp.sys.apple2    |    Discussion about Apple II micros    |    56,720 messages    |
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|    Message 55,188 of 56,720    |
|    Steve Nickolas to All    |
|    Re: ProDOS boot block?    |
|    28 Dec 21 03:11:55    |
      From: usotsuki@buric.co              Currently the most efficient x86-side code I can come up with is this:              B8 01 02 B9 02 00 30 F6 31 DB 8E C3 BB 00 7C 26       C7 06 FE 7B CD 13 EA 00 7C 00 00              That's pretty much the same code I described before, except that once the       registers are set I place an "int 13h" at 0000:7BFE and jump hard to it.       (This 8086 code could probably be done even more efficiently.)              Since I haven't yet RE'd the entire ProDOS bootloader - only as far as       $096C, and that only basically - I'm not really sure what code might be       safe to maneuver around without breaking things, other than the stuff that       I was able to identify as being part of the SOS chainloader.              Still, this seems to suggest that a 6502-8086 diglot bootloader is indeed       possible. (It would only really be feasible on a 1.44 MB floppy though       which is quite rare on the Apple ][ line!)              -uso.              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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