GARTHWILSON wrote:
Oneironaut wrote:
I have decided to use an SDCard as the external cartridge as a bare SPI Flash memory is just too expensive.
There's Microchip's SST25VF064 8MB SPI flash in an SO-8 for $3.79 in singles, at
http://www.mouser.com/ProductDetail/Mic ... rUXA%3d%3d (I've used this one), and Cypress/Spansion's S25FL512S 64MB SPI flash in an SO-16 for $5.89 in singles, at
http://www.mouser.com/ProductDetail/Spa ... %2fuMH8%3d . Spansion has another one that's 128MB in an SO-16, but it has two dice, so I think you'd handle it like two separate 64MB flash memories. I suspect 64 megabytes will be plenty for a 6502 system though.
The SPI has the advantage of lesser boot code on the Diode Matrix, but the SDCard option allows easy cross development on the PC.
With the SDCard, you can just save images and graphics directly to the card and then drop it into the Vulcan Cartridge Port.
It would also be cool to see the 6502 handle FAT32 and exFAT.
Another option I am tossing around is having a "KickStart" SDCard. Here is how that would work...
1) On power up, Vulcan loads the Diode Matrix Micro-Boot program and lets the 6502 start running.
2) The Micro-Boot program reads 64K worth of Program Memory code in RAW mode from a FAT16 formatted SDCard.
3) Vulcan would then display "Insert Cartridge" and wait for a large SDCard (FAT16, 32, or EX) to be inserted.
4) From there, Vulcan has full access to the entire SDCard using a proper file system.
The KickStart plan removes all speed issues, and offers unlimited storage.
Vulcan-74 has more than enough power to play fullscreen video and stream 4 channal audio, so extra storage space is good!
Just an idea.
Brad