Component suppliers such as Mouser, Farnell, Digikey and RS sell 74LS logic, you don't have to use Texas Instruments, the N of the part just means plastic DIL package. Come to think about it, there is another 74LS245 driving the 1MHz bus, if that's in a socket you could try that one and see if anything changes.
It's best to look the circuit over with an oscilloscope, a multimeter won't help much. Don't try to use other families of logic for IC14 as it's part of an assumption made by the designer of the circuitry to have the timing response of a 74LS245 in that spot.
I've tried with various levels of success and failure 74F, 74S, 74HCT, 74ACT and 74FCT with faster logic there's a possibility of glitches being taken seriously by the system and lock ups, corruption and burn outs. I've had a lot of laughs building Beebs from scratch using different combinations of logic and seeing how squirrelly things get![:lol:]( "Laughing")
It's best to look the circuit over with an oscilloscope, a multimeter won't help much. Don't try to use other families of logic for IC14 as it's part of an assumption made by the designer of the circuitry to have the timing response of a 74LS245 in that spot.
I've tried with various levels of success and failure 74F, 74S, 74HCT, 74ACT and 74FCT with faster logic there's a possibility of glitches being taken seriously by the system and lock ups, corruption and burn outs. I've had a lot of laughs building Beebs from scratch using different combinations of logic and seeing how squirrelly things get
Statistics: Posted by maniacminer — Mon May 06, 2024 2:23 am