On 5/29/2013 9:55 AM, Gerrit Heitsch wrote: > On 05/27/2013 07:57 AM, Baltissen, GJPAA (Ruud) wrote: >> Hallo JG, >> >> >>> Something I'd find useful is being able to have more than 16K >>> available in the 16K cartridge slot, and to be able to page >>> the cartridge out. Then I could copy greater than 16K code >>> from the cartridge to RAM, than page out the cartridge. >> >> A 27512 EPROM can handle 64 KB. A 74LS273, a resetable latch, can >> handle the pages plus 'paging out' the cartridge. > > Another useful TTL in that respect is the 74LS175. It's used in the > banking logic of the 264 series. It only has 4 Bits instead of 8 but > all of them are available as normal and inverted. > > Gerrit > > > > > Message was sent through the cbm-hackers mailing list Speaking (writing) of bank registers, anyone know of a TTL option that has a falling edge trigger? Yes, I can do an inverter, but would rather not. Use case is VIC-20, which won't work on rising edge of Phi, because not all of the data is valid on rising edge. Jim -- Jim Brain firstname.lastname@example.org www.jbrain.com Message was sent through the cbm-hackers mailing listReceived on 2013-05-30 07:00:02
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