We used to do that on our 360/67 (read dials into memory during IPL) until we got a machine check for a storage error (dusty contacts IIRC).
Mike At 03:44 PM 5/25/2015 -0400, you wrote: >You might also like to know of an undocumented instruction specific to the >360/20. >This was a form of the Diagnose (opcode X'83') which allowed me to read the >hex dials >on the console into storage. > >This was extremely useful as I had the job of converting 1401 Autocoder into >360/20 Assembler >and this instruction enabled me to replace the sense switches. > >On later machines under DOS I used the UPSI card. > >Forgive me, but it's 50 years since I coded one of those and I can't remember >the operand, but >I'm sure someone will.
