Subject: [stella] Supercharger Bankswitches and RAM access!|
Date: Fri, 14 Mar 1997 00:20:44 -0500 (EST)
Hi! I posted a message a few days ago. I'll try to be more specific. I think the only thing I'm doing not right yet are the RAM access routines. Poking is a two step process, something like (write enable assumed): <0xf100 ----- / \ 1.lda $f000,x (x=0xf0 for example) 2.cmp $f72b This will poke 0xf0 to to location $f72b. I need to know what kind of instructions will be used for value specification, so far I take absolut, absolut-x, absolut-y, indirect-x and indirect-y. What kind of instructions will be used for poking? (absolut, absolut-x, absolut-y, indirect-x and indirect-y) I know for sure CMP,AND,BIT,LDA, are there any others? How is the value determined using indirect-x and indirect-y? How is the address determined using indirect-x and indirect-y? Which instruction preserve the value, which instructions don't? (All implied instruction?) (for sure I know: NOP,TAX,TAY) Since address fields below 0xf000 initiate a poke, what about addresses in that region that are poked to, is it possible, if so can a poke follow directly? Bye Chris PS. My stella now runs Frogger, Dragonstomper, Rabbit and a few others It doesn't run (well) Suicide Mission, Phasor Patrol, Communists... -- Archives available at http://www.biglist.com/lists/stella/archives/ E-mail UNSUBSCRIBE in the body to stella-request@xxxxxxxxxxx to be removed.