Zeroing core. 2575
MOV -(PC), -(PC)
IIRC
It didn't leave zeros behind. I'm not sure what happened at address zero.
Which reminds me of the time we went to a certain military establishment which was having troubles with their PDP-11 at the time. It was one of those rooms where they changed all the line printer paper for stock of a different colour before we were allowed in.
I agree is doesn't matter how it's scrubbed. I'm having problems figuring out how one can verify that the 1000 randomly set bits in the memory page (I'm looking...
We loaded the diagnostics from paper tape, and ran them. It looked as if it might be either a memory board error or a backplane problem. We powered down, swapped a couple of memory boards, powered back up, entered the PC and ran the program again. One of the staff pointed out that we hadn't re-loaded the paper tape. "No", we said "it's core store, and it doesn't lose the data when it's powered off". "Oh dear", he said, as he realised that there was probably top secret data still in the memory boards, and that not only were we in the room with it, but he might well have let us or the DEC field circus technician walk out of the room carrying it.
Various procedures were revised as a result of that incident, and IIRC a small program had to be written to erase the contents of memory.
-- "Perfection in design is achieved not when there is nothing left to add, but rather when there is nothing left to take away." -- Antoine de Saint-Exupery
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