On 21/09/15 14:15, Noel Chiappa wrote:
> From: tony duell> In some cases it should be possible to write a machine code program > that executes on 2 processors with wildly different instruciton sets. I have this bit set that I was told (or something, the memory is _very_ vague) that early versions of the KL-10 had this hack; the root block on the disk was the boot block both the PDP-10 and the PDP-11 front end machine, and the first instruction or two was very cleverly construced and sent the two machines different ways. Alas, I looked in the front-end PDP-11 code (in the KLDCP; directory) and saw no signs of this, so maybe it was an urban legend?
I can't find a definitive reference right now, but I *think* that the ODS-1 disk format was first used on the PDP-11 and then later used in early versions of VMS. I *think* that it was arranged such that a PDP-11 booting and a VMS system booting could be done from the same disk by arranging for each to interpret the boot block in
a way that each was happy with. Antonio arcarl...@iee.org
