Brad> Does anyone know how to run maindec-11 diagnostic paper tapes? Brad> Say I wanted to run maindec-11-dfkaa-b1-pb which is an 11/34 Brad> cpu test. Brad> I know I could run xxdp, but if I had no disk and I wanted to Brad> run the test from paper tape, what's the procedure? Brad> Naturally I'd like to try it on simh first... It's been 25 years, but what I recall is: 1. Load the papertape bootstrap loader. 2. Use that to load the regular papertape loader. (Or am I mixed up with the RIM and BIN loaders on the PDP-8?) 3. Use that to load the diag. It may start automatically. I think the papertape format has a transfer address mechanism. Failing that, I think all old diagnostics start at the same start address. 200? 400? Some low number like that. You may need to set the switch register to all zeroes before starting (I'm pretty sure that's it -- maybe all ones but that sounds wrong). The switches control certain common low level things, like "scope loop" or "halt on error". paul