Subject: Re: [stella] Re: Help with efficient code From: Greg Miller <gmiller@xxxxxxxx> Date: Tue, 30 Sep 1997 05:49:51 -0500 |
Jim Nitchals wrote: > jump_table: > dc.w framistat ; your assembler may prefer .word > dc.w dohickey > dc.w whachamacallit > dc.w thingy > dc.w dodad > num_entries equ (*-jump_table)/2 ; some assemblers use $, not * > ; to refer to current address > (or if all else fails:) > num_entries equ 5 ; but it isn't as nice Small note: I'm not sure about the 6507, but the 6502 and many of its variants won't work properly, if a pointer in the table crosses a 256-byte page boundary. Make sure your tables are either word-aligned or don't cross pages, unless someone (Jim?) knows for sure whether the 6507 has this bug. -- Video games and CCGS: http://www.angelfire.com/tn/squirrels TW (online game): http://www.geocities.com/SiliconValley/Bay/1367 Magic cards: http://www.angelfire.com/tn/squirrels/magic.html ***** ATTENTION NEWBIES: Limit signatures to four lines! ***** -- Archives updated once/day at http://www.biglist.com/lists/stella/archives/ Unsubscribing and other info at http://www.biglist.com/lists/stella/stella.html
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