smaller HP 82166A with 32-pin connector

[KimH]

This TTL Versions should help with the differences.

Also for those of us dealing with OLD gear, this video might be helpful Logic IC Pitfalls

74HCT74 is ordered, didn't have any in my drawer

(09-09-2021 04:56 AM)Dave Frederickson Wrote:  

(09-08-2021 04:51 PM)Klaus Overhage Wrote:  While looking for a 74LS74, I came across a 7474 with no letters in between. Didn't know that these TTL-ICs are also available without letters, is probably an early version, but behaves exactly like a 74LS74.

No, a standard TTL 7474 does not behave exactly like a Low-Power Schottky device. The std TTL part outputs can sink 16mA while the LS device outputs can only sink 8mA. See the datasheet.
https://www.ti.com/lit/ds/symlink/sn54ls74a-sp.pdf

Dave