I thought I did, but what I have is the HP 12845B Line Printer interface card, for which I could find the documentation. Unfortunately, looking at the schematics, it does not seem to be based on a 12566B interface. Reading some more, it is meant for the 2607/261x series of printers, which apparently use a narrower 7 bit interface (the 12566 is a 16 bit interface card). But maybe you can inspire yourself from it. Marc
-----Original Message----- From: cctech [mailto:cctech-boun...@classiccmp.org] On Behalf Of J. David Bryan via cctech Sent: Wednesday, July 05, 2017 2:36 PM To: Classic Computing List Subject: HP 12653A line printer interface Does anyone have an HP 12653A line printer interface? It is used to connect an HP 21xx/1000 CPU to an HP 2767A line printer. I am unable to find a manual for this card, but the HP "General Purpose Register Diagnostic" manual suggests that it is a modified HP 12566B Microcircuit interface. I'm trying to determine what modifications were made, so that I can model it accurately in the SIMH/HP2100 simulator. If anyone has this card and wouldn't mind sending me high-resolution photos of the front and back, I'd be most grateful. -- Dave