On Sun, 6 Sep 2015, Jay West wrote: > Here's a non-exhaustive but useful list of compatible parts for each: > > 4K parts > Signetics N82S141 > Harris 7641 > MMI 6341 You can add National 74S474 to this group. I've tried it, and they work. Mike Loewen mloewen at cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/