From: Marko Mäkelä (marko.makela_at_hut.fi)
Date: 2003-01-25 20:18:28
Hi all, I have made some experiments with the VIC-20 cartridge prototype, which only has 512 kilobytes of flash ROM. I've started writing a flashing utility that can successfully clear the chip. (I've verified it by reading 8 kilobytes of $ff from the chip.) However, when I program 8 kilobytes of the chip (that would be random locations in the chip, since I have shuffled the address lines to simplify the circuit board), some bytes that should be $ff are instead $fe or $fd. The embedded programming algorithm in the chip does not report any errors, and my program also checks that after programming a byte, it must read back the same within 256 retries. I also tried a modification that would skip any $ff bytes, but it didn't change anything. All other bytes than these $ff's are programmed correctly. Has anyone else had similar experience? Any ideas or suggestions? The next logical step is to read the whole chip (off the system) and check if the remaining 512-8 kilobytes of the chip are $ff, as they should. I hope they are, since anything else would indicate a hardware problem. Marko Message was sent through the cbm-hackers mailing list
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