On 5/14/22 15:35, dwight via cctalk wrote: >>> You are stuck with using an original 7474 family assuming this is driving >>> other early TTL. 74LS74, and others simply don't have the drive capability >>> to work. >> I know LS has less fanout, but is it not able to drive plain 74xx at all? >> That doesn't sound right. If the circuit in question runs near the fanout >> spec of plain 74 the yes, 74LS won't work. >> >> Spec sheets and the actual schematic will give a definitive answer. >>
I've got a whole parts drawer full of 74S74s, which I believe exceed the output current capabilities of the original 7474. There's also the 74ABT74, if you want a beefer BiMOS version. Heck, I can probably come up with a couple of crufty old 74H74s... --Chuck