> They can be replaced by 27128 EPROMs (or 27256 with the data in the > upper half) if one little detail is fixed. The 27128 expects Vpp on > pin 1 and, in normal operation would like to see Vcc (+5V) there. The > ROM sockets on the C16 and C116 PCB take this in account and have pin > 1 connected to +5V. The ROM sockets in the Plus/4 do not (all 4 of > them) and it look like the cartridge you photographed doesn't either. > Usually the EPROMs work anyway, but it's not according to spec. So if > you do your own layout, it would be a good idea if you'd connect Pin 1 > of each ROM socket to +5V on your board. > Hi, pin 1 is connected to +5v on the standard +4 cartridge boards, like Didiers. You can't see the trace though as it's on the top side hidden under the ROM's. Rob Message was sent through the cbm-hackers mailing listReceived on 2012-04-26 21:00:03
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