Hi, My KA10 implements the TM10 this way. Also it appears that the dumps on pdp10.trailing-edge.com etc are written this way.
Rich > Rich Alderson wrote: > > On 9-track tape, in the default mode for all PDP-10 operating > > systems, referred to as core-dump mode, 36 bit words are stored > > into 5 8-bit frames (with logical parity) as follows: > > > > bits 0-7 x x x x x x x x P > > bits 8-15 x x x x x x x x P > > bits 16-23 x x x x x x x x P > > bits 24-31 x x x x x x x x P > > bits 32-35 0 0 0 0 x x x x P > > I thought so too. But I had a reason to look into chapter 3 of the > TM10 maintenance manual, and I saw something interesting. > > Apparently, the TM10 does a slight variation (or is this the canonical > version?) of the core dump format. It writes the last *six* bits to > the last frame, so bits 30 and 31 are actually written to two places: > > > bits 24-31 x x x x x x y y P > > bits 32-35 0 0 y y z z z z P > > When reading, it inclusive-ors the overlapping bits. > > _______________________________________________ > Simh mailing list > [email protected] > http://mailman.trailing-edge.com/mailman/listinfo/simh -- ========================================================================== Richard Cornwell [email protected] http://sky-visions.com LinkedIn: https://www.linkedin.com/in/richard-cornwell-991076107 ========================================================================== _______________________________________________ Simh mailing list [email protected] http://mailman.trailing-edge.com/mailman/listinfo/simh
