Posts: 29
Threads: 7
Joined: Jan 1970
From my 75C manual, page 128.
Command "assignio" will tell you how many devices are on the loop.
This will respond with "Device # 1=': " with the cursor after the :
You can enter pr for the printer.
Command "list io" will show the devices assigned.
I tried this on an HP-75D (nameplate shows AT&T) and it found the printer, but I couldn't get it to print. With my HP-75C and the Extended IO ROM, printing works great. If I figure it out later, I'll send more information. The Extended IO ROM should have been standard. It makes many things easier to deal with on the 75 series.