> On Jul 24, 2020, at 2:28 PM, David Gesswein <d...@pdp8online.com> wrote: > > On Fri, Jul 24, 2020 at 06:12:17PM +0000, Paul Moore wrote: >> Not helped by not knowing what KSR really means. >> > > Keyboard send receive. A model 33 teletype without paper tape. > ASR was the model with paper tape, Automatic send receive. > > DEC used teletype's that generated mark parity. From the manuals keyboards > were > available to generate other parity. A reasonable amount of old code for > PDP-8's assumed mark parity. Later code ignores the upper bit. > > I thought the high bit setting would be turned off if you used set tti 7b or > 8b but never verified.
7b, yes. But that only helps with software that sets the top bit on output, as some old Unices do. It doesn't help with the problem Paul M raised, which is software that insists on mark parity input. The right answer would be a tweak to the console emulation in SIMH pdp11. I wonder if this was done for PDP8 and not PDP11 because it was known to be needed on the one but people hadn't run into it for the other. paul _______________________________________________ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh