I have a few weeks to kill until my Handheld PC's PCB's arrive from the manufacturer so I decided to get a Raddica to hack up while I wait.
I got the thing open and was about to remove the Rom and wire up a Cartridge port, when I was reminded of an old project I did a few years back ...
A few years ago I replaced the EPROMS on an old ARCADE (Jamma) PCB with a DIY PCB that emulated the EPROMS with a number of battery backed SRAM's, at the time I just used a small CPLD that connected to a standard Parallel port of a PC. I produced a small DOS application clocked out the contents of Binary ROM files down the Parallel port to the FPGA that clocked the data into the battery backed SRAM's, after the data was sent down, the board was inserted into the Arcade PCB EPROM sockets and the SRAM's looked like EPROM. now you may be wondering what the hell this had got to do with the Radica GOAC, well I was just wondering if I could make up a small PCb to take the Radica rom onto a small connector and have a small PCB with SRAM and a 3V lithium (for Sram backup) and do the same thing to emulate the standard Genesis cartridges but with SRAM. This way you can have a really small cartridge for genesis games instead of having to use the original carts.
You would have to have a better way of programming the SRAM card. a PIC micro connected to a PC serial port would do the job.
If you are still wondering why use SRAM, well you can program it very quickly. This is just like that way a Flash linker cartridge works on a GBA but with Battery backed SRAM instead of FLASH.
Something like a 256K x 16bit SRAM (AS7C34098-10JC 4mbit) would do the job -
http://www.datasheetarchive.com/datashe ... 38649.html
Anyone think this is worth doing ? or am I just going way too far
?Cheers,
hand_held
