Hi guys, Love watching all this R&D in real time. Love the idea of the Final Cart version for the Vic-20. I've been meaning to order from Mr Brain for some time now. I'll be sure to add one of these to the list when they are available. AU$ is too weak currently (69 cents) but hopefully in the future it will recover some. Wondering about adding a faster CPU to the mix? I would think such things are quiet cheap now. Or even just a spot on the board for it so a user can add it later if wanted. I know it's the whole Super CPU saga of needing support firmware but if the hardware exists perhaps people will write for it later? Just an idea. :) Keep up the great work! ~Ken .-.-. On 25/09/2015 10:20 AM, Terry Raymond wrote: > Wow I didnt realize it was that many years ago either where do they go. > > Terry Raymond > > On Thursday, September 24, 2015, Pasi 'Albert' Ojala <email@example.com > <mailto:firstname.lastname@example.org>> wrote: > > On 09/24/15 21:48, Anders Carlsson wrote: > > Pasi Ojala wrote: > > However, if the memory were visible to VIC-I > > > Doesn't it take internal modifications to make any sort of > memory available to the VIC-I, or can it somehow be achived > through the expansion bus? > > Yes, and it was one thing xvic had wrong at some point. > > There is VR/W signal on the expansion port. > > Now, where are the schematics... Here, but where's the cartridge > port.. > > Only CA0 to CA15 appear in the cartridge port, not VA0 to VA15. > 65245 buffers allow CA (6502 address) to drive VA (VIC-I address) > and it is strictly one way. The internal RAM is connected to the > VA bus. So, VIC-I can only access internal memory, not any > expansion memory. > > Can the VIC-I read from memory connected to I/O blocks 2 and 3 > ($9800 - $9FFF if I recall correctly) if that memory is > connected from the cartridge? > > VIC-I can't provide the address. Another buffer connects CD (6502 > data) and BD (VIC-I data) buses. This one had direction controlled > by CR/W, and while CR/W is high during video access, VIC-I can't > see the data on the CD bus (cart port). Unless you force the CR/W > low from the cartridge port... > > > I believe the VIC-20 scene in latter years has developed a > couple more image formats since Pasi's format 15+ years ago, > but I believe those are even more CPU intensive with increased > FLI like colour resolution. > > Time flies... :D > > -Pasi > > > Message was sent through the cbm-hackers mailing list > > > > -- > Sent from Gmail Mobile Message was sent through the cbm-hackers mailing listReceived on 2015-09-25 01:00:56
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