Subject: Re: [stella] a $16 question... From: Chris Wilkson - MCD <cwilkson@xxxxxxxxxxxxx> Date: Fri, 30 Jan 1998 09:20:43 -0800 (PST) |
> > The info I have doesn't say anything about initialization. Is this handled > > by software? Ie. are the last few bytes of each 4K page identical...same > > RESET/SWI vectors, etc? (This is what I think) Or does the cartridge always > > powerup to the same 4K page? > > Random startup is not a big problem. Besides the reset/swi vectors you > need to duplicate a bank-switch to get the game started: > > org $x000 > sta $FFF9 ;switch to main startup bank, in this case $F000 > > bankXcode: ;in $F000, this is the actual game startup routine > ... > > org $xFFC ;reset/swi vectors in case we start in this bank > dc.w #$x000 > dc.w #$x000 > > I think that's how it was actually done in Atari carts, but even if not > it should always work anyway through the magic of software ;) This is what I thought. Although it's just as easy to designate a startup pa page and force it during the powerup sequence. With no extra parts required. But doing this only saves 12 bytes. Not a huge gain with 16K on hand. :) -Chris -- Stella list is Administered by krishna@xxxxxxxxxxxx <Glenn Saunders> Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/stella.html +-shameless plugs-------------------------------------------------------+ | Stella documentary at http://www.primenet.com/~krishna | | Nick's VCS links via http://www.primenet.com/~nickb/atariprg.htm | | Write the best game, win framed autographs of famous Atari alumni!! | +-----------------------------------------------------------------------+
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