On 2/10/22 09:11, dwight via cctalk wrote: > I hope you are not thinking it would test an Intel 4004 or a 8008? That would > be a stretch. For the 4004, there is only a narrow range of frequencies it > runs under. I'm not that familiar with the 8008 but suspect it has similar > restrictions. Both use dynamic registers. Both use PMOS voltage levels( 15V > ). A 4008 RAM chip is not the same as an intel 4008 chip. > It is conceivable to use a logic tester to test a i4004 but it would be a lot > of effort. Each instruction does unique operations inside of the i4004. One > would have to have 256^2 inputs to fully test a i4004 from the pins. Even > then there are a similar number of replies that would have to be checked. One > could at best have a simple confidence test that it appeared to be working, > as most failures of IC cause complete failure of the chip. Even Intel never > fully tested parts going out the door. Even for a processor as simple as the > 4004, a complete test is not practical. There are not test circuits built > into it either. > Erturk Kolcalar makes a retro processor exerciser. It basically runs through > a USB port from a PC. In its current form, it can't fully test a i4004 > because it doesn't meet the proper frequency ( some will work but others > won't, but still be functional i4004s ). It runs code loaded from the PC. He > currently has the code for the Busicom calculator running. > I don't recall if he has one for the 8008?
Is it safe to assume that the chip tester works with TTL-level signals only? So no ECL or PMOS, for example? --Chuck
