28 Oct
2014
28 Oct
'14
1:22 p.m.
On Oct 27, 2014, at 10:06 PM, Clem Cole
<clemc(a)ccc.com> wrote:
yes: http://repository.cmu.edu/cgi/viewcontent.cgi?article=3241&context=comp…
<http://repository.cmu.edu/cgi/viewcontent.cgi?article=3241&context=compsci>
I had a 60 running v7 years later. we also toyed with adding CSV/CRET but never did it
because we got an 11/70
Problem with the 60 was it lacked Split I/D (as did the 40's). We kind of relied
on that for the kernels towards the end of the PDP-11 days,
We struggled with the lack of I/D on the 11/34 and 11/23 at BRL but finally gave up when
TCP came along. We just didn't have enough segments to handle all the overlaying
needed to do. I recycled all the non split-I/D machines into BRL GATEWAYS.
Of course, there was the famous (or imfamous) MARK instruction. This thing was sort of a
kludge, you actually pushed the instruction on the stack and then did the RTS into the
stack to execute the MARK to pop the stack and jump back to the caller. I know of no
compiler (either DEC-written or UNIX) that used the silly thing. It obviously
wouldn't work in split I/D mode anyhow. Years later while sitting in some DEC
product announcement presentation, they announced the new T-11 chip (the single chip
PDP-11) and the speaker said that it supported the entire instruction set with the
exception of MARK. Me and one other PDP-11 trivia guy are going "What? No mark
instruction?" in the back of the room.