willmurray461
Experienced Member
I bought this manual a while back from a seller on eBay thinking it was for my IBM 3270 PC, but after reading it, I found out it was for a rare IBM card that I had never heard about before. It's called the IBM 3270 Personal Computer Attachment, and allowed you to use a 3278 terminal as a monitor and networking device for your 5150, along with allowing a 3278 keyboard to be used with your PC. The adapter connected to a breakout box which split three ways. Cables would attach on one end to the breakout box and to the terminal in two places and the 3278 keyboard on the other. The 3278 terminal needed to have the special IBM 3278 Personal Computer Adapter option installed in order to communicate with the card. The manual seems to be a very old one from the early days of the PC. It came in a light gray binder like other early IBM documentation, only references PC DOS 1.1, and all pictures of the 5150 are the early revision A models with the (RS-232? I think it is.) port cover. My guess is it was immediately replaced by the 3278 emulation cards. It came with some software labeled "Data Transfer: VM/CMS," "Data Transfer: TSO," and "Customization." All are version 1.00 copyright IBM 1982. The manual also has some schematics which detail exactly how the card works. If someone wanted to, it looks like they could recreate the card if they wanted from the documentation in this book. There's a lot of other technical documentation I can't understand, diagnostics, data transfer, translation, and encoding, but maybe someone else could understand it when I convince myself to scan the whole thing. I would love to see one of these things one day. Hopefully the vintage computer community can track one of these down. Or maybe, someone already has one of these. It sounds pretty awesome to be able to use a 3278 as a display, and a "beamspring" keyboard with a 5150.