Subject: Re: [stella] a $16 question... From: Greg Troutman <mor@xxxxxxx> Date: Fri, 30 Jan 1998 09:01:25 -0800 |
Chris Wilkson - MCD wrote: > > > Maybe. At any rate, 100 boards is enough interest for me to do the design. > > The cost of a bare board shouldn't be terrible. And I think I can get away > > with only 2 chips...I'll hafta dig out my bank switching info to verify that. > > At any rate, I'll have an estimate for a EPROM-less board by Monday... > > 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 ;) -- mor@xxxxxxx http://www.crl.com/~mor/ -- 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!! | +-----------------------------------------------------------------------+
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
Re: [stella] a $16 question..., Chris Wilkson - MCD | Thread | Re: [stella] a $16 question..., Chris Wilkson - MCD |
Re: [stella] a $16 question..., Chris Wilkson - MCD | Date | Re: [stella] a $16 question..., Chris Wilkson - MCD |
Month |