info-atari@ucbvax.UUCP (01/21/86)
-------------------------- Re: messages 1219, 1272-- > > On the subject of bank switching in the supercartridges, does anyone > know the software proceedure for getting the cartridge to swap? > Perhaps writing to a particular address in the cartridge address > space? Below is what OSS says about turning their bank-select ROM cartridges (BASIC XL, MAC/65, Action) on and off (uncovering RAM) without confusing the OS. Note that remarks about location 3FAh may not be needed for other than DOS/XL; it is not mentioned in my OS documentation and I have not experimented. If you are using DOS XL with the option that puts most of DOS in the address space occupied by the cartridge, then you better not select out the cartridge and mutilate that RAM! ---------------------------------------------------------------------- Bruce Langdon L-472 langdon%lll-lcc@lll-crg.ARPA Physics Department "langdon#bruce%d"@lll-mfe.ARPA Lawrence Livermore National Laboratory Livermore, CA 94550 (415) 422-5444 UUCP: ..{gymble,ihnp4,seismo}!lll-crg!lll-lcc!langdon ----------------------------------------------------------- >From OSS bbs (408) 446-3451: Re: Turning Our Carts ON/OFF (S. Grimm) 9/16/85 12:00:00 size: 772 Sorry that it took so long Steven, but we've finally compiled the right way to turn the carts on and off: To Turn a SuperCartridge OFF: 1 Close Channel 0 2 Wait for the LSB of the clock (20) to change value. 3 Do an SEI 4 Save $AFFF so that you can restore the cart to its previous state. 5 STA $D508. This turns cart off. 6 Poke $3FA,0 to tell OS that there is no cart. 7 Poke $6A,$C0 (RAMTOP) to tell OS that more RAM is available. 8 Do a CLI 9 Open #0,12,0,"E:" To Turn a Supercartridge back ON: 1 Perform steps 1-3 from above. 2 LDX with value saved in 4 above. 3 STA $D500,X. This turns cart on. 4 Poke $3FA,1 to tell OS that there is a cart. 5 Poke $6A,$A0 to tell OS that less RAM is available. 6 Perform steps 8-9 from above. ---------------------------------------------------------