Subject: Aw: Re: [stella] Bit flip From: cybergoth@xxxxxxxx Date: Mon, 10 Sep 2001 11:00:20 +0200 (CEST) |
Hi Andrew! > Table-lookup, 256 bytes. Index your original value to get the bit-flipped > value :) > Somehow I think that's not what you were asking. Uh... something like that was asked for? Hm... straightforward I'd say a loop like this: LDX #$07 LDA value loop ROR ROL value DEX BPL loop should do... For the table: Since only 1 bit is set, some memtable wouldn't need to waste a whole page, something like this'd be enough: ORG FX01 .byte $80 ORG FX02 .byte $40 ORG FX04 .byte $20 and so on... messes up the page, but leaves room for another 248 bytes :-) Greetings, Manuel ----------------------------------------------------------------------- Keinen grünen Daumen? Individuelle Angebote zu Dachbegrünungen und Blumendekorationen. http://www.nexgo.de/c/pub/redir.php/yo6 ----------------------------------------------------------------------- - Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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