Here is a experience from DK forum members who made this possible about how to reflash CARPROG Mcu AT91SAM7S256
Tool use: Carprog clone v8.21 firmware
We need the stuff:
2- Jtag programmer
3- Jtag software
We need to prepare the Carprog to connect to Jtag programmer but first the flash need to be erased, the Jtag function in mcu is disabled, you can’t connect to the mcu before erase the flash. Remove the AT88SC eeprom from the board, please note where is the pin 1 in eeprom before remove:
Carefully lift the pin 55 (reset) of the mcu and solder a wire and secure it with a small ammount of silicone (you don’t want to broke the pin in the process).
Connect the Carprog (with the pin 55 dissconected) to the 12v supply, wait about 10 seconds and connect the wire from pin 55 to Vcc (3.3V) in Carprog:
Wait from 5 to 10 seconds after connect the 12v supply, the flash content will be erased and the Jtag option of the Mcu will be enabled now. If not work leave connected for about 3 to 5 minutes. Disconnect the 12v supply from CarProg full and remove the pin 55 wire from vcc. The pin 55 must remain disconnected until the programming process is done.
Ok, that’s it. I make it; and you try on you risk.