Well maybe not, but the first in the 23-001A1 sequence of part numbers was used in the PDP-8/e EAE. I was troubleshooting a problem with an EAE in which the step counter wouldn't load. There are 2 fusible PROMs in the circuit and I noticed they are 23-001A1 and 23-002A1. Maybe there is a 23-000A1.