[TUHS] PDP-11 questions

Mark Longridge cubexyz at gmail.com
Mon Jan 25 03:37:25 AEST 2016

Ok, I got a few questions about PDP-11.

First, I was wondering when Bell Labs got that first PDP-11/20 what
software (if any) came with it? I assume when one bought a PDP-11/20
you would get some type of OS with it.

According to the folks at alt.sys.pdp11 the PDP-11 computer doesn't
have anything equivalent to a PC's BIOS. But I know a bit about what a
PC's BIOS does and that includes RAM Initialization. Wouldn't the DRAM
on the PDP-11/something need to be initialized too? Perhaps an older
PDP-11 doesn't have DRAM but surely the later models did?

Now the last question has to do with what made the PDP-11 architecture
so great. Part of that had to be the relatively affordablility of the
PDP-11 and of course it was the machine that made Unix possible. It
seems though that there should have been a PDP-11 based desktop and as
far as I can tell that didn't happen. Instead we got a bunch of micros
with 8080, z80 and 6502 cpus, but nothing that could run Unix, at
least not a Unix v7 with source code.


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