On 30 Dec 2008 13:59:20 -0800, Chuck Guzis wrote: Indeed they do. Six months ago I was given a DOA Rockland-Wavetek 5820B spectrum analyzer that had a disconnected power supply lead. Fixing that brought up the unit sans random pixels on the displayed alpha-numerics. I finally traced the problem to a 8S115 PROM that was feeding a 8X300 (two other CPUs in the beast - Z80s). After decoding the ROM I began editing the data to restore the missing 1-bits and reprogrammed the very same chip. After the first half of the alphabet, the remainder of the letters magically appeared. Once the bit "heals" it is possible to reblow it. How long this fix is going to last is anyones guess - probably another 20 years... CRC