Hello! Anders Carlsson wrote: > Somehow it sounds like you're describing a C64 version of the VIC-20 > Final Expansion? Yes, it is definitely going in this direction. But as I reviewed all the "final", "universal" and "ultimate" cartridges already available, I noticed that they are based on similar approaches: * Stash as much FLASH as possible to store cartridge images. * Provide the method of flashing the images from PC, and a menu to choose an image from the computer. * Attach some useful circuitry such as SD-card interface for added value. This is a nice approach, but severely limited to just emulating cartridge images plus whatever extra circuitry is glued in. What I want to do now is another step further: * Instead of Flash, use a reprogrammable FPGA chip. * Provide a solution to connect a SD-card. * The boot ROM will load selected FPGA image from SD-card and put it into the FPGA. This way the cartridge will not be limited to emulating just other ROM cartridges. The FPGA can do anything we program it to. If we just want to emulate a cartridge, then FPGA has memory so it will just serve as a ROM chip. But it can be programmed to act as REU as well. Or an Ethernet interface, or USB host, a Z80 card even. It can be anything. As I checked part prices, the cost of building the card with one FPGA, one CPLD, 5V to 3.3V interface, SD-card connector, 512k SRAM plus some glue should be about $50 apiece. Not very bad. I envision then a website where you can buy one item (the board), and then download all kinds of FPGA images and simply put them on the SD-card to reuse. Maximum user-friendly - no flashing the FLASH memory in the card, just a matter of copying one file. Regards, Michau. Message was sent through the cbm-hackers mailing listReceived on 2012-05-09 10:00:09
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