Fwd: [roys-tech-chat] Building replacement for TTL counter DM8552 (National Semiconductor)

It should be in the National Semiconductor 1974 (IIRC) "Logic" databook. I don't have mine handy, but one could probably get a photocopy at Halted in Sunnyvale. National Semiconductor, Signetics, Motorola, and probably other vendors had their own proprietary series of TTL chips before it became apparent that the 7400 series was going to win. It was a source of considerable confusion that the Motorola TTL parts were the MC4000 series, which was completely different from the RCA CD4000 series CMOS (and its equivalents). Because Motorola was already using 4000 series numbers for their TTL, when they added CD4000 equivalent CMOS parts to their product line, they added a leading one, making it the MC14000 series. I've long wondered how much money one could get for the MC4040 on eBay: "rare Motorola 4040 chip" :-)