newman (12/03/82)
The only place I've seen a 4 mhz 6502 used is by the Spracklens in their custom tournament Othello machine. It generates so much heat they had to put a cooling unit of some kind in it (I think more than just a fan). It is possible that they just kept trying 2 meg parts until they got one that worked (or is there a real 4 meg chip?). Have they got peripheral chips (6522, 6532, ...) that run at that speed?
mclure (12/13/82)
#R:utcsrgv:-75600:sri-unix:2600004:000:594 sri-unix!mclure Dec 13 08:20:00 1982 Hadn't heard about the Othello 4mhz 6502. However, two of Fidelity's chess machines use a 4mhz 6502. The sold-out 'Elite' and the new 'Prestige'. I disassembled the latter to see what was going on. There wasn't a fan, just a gigantic heat-sink latched onto the top of the 6502. I believe Kathe Spracklen said that they select the 6502's which run a little faster than the distributed 2mhz and then turn up the clock speed and attach a heat-sink. The above products have a very good reliability record (not to mention playing the strongest chess of commercially available units). Stuart