16 Dec
2012
16 Dec
'12
10:20 a.m.
I'm not sure what "standard SLUs" means
across different architectures
and buses and such. The standard PDP-11 SLU, to the extent that there
is such a thing and to the extent that the info I've found is accurate,
Actually, the original PDP11 character devices -- the SLU, paper tape,
punched card reader, etc were remarkably similar at the register level.
In general there were 4 registers, receiver CSR (Command/Statues regiater
(or control/status register), receiver data. transmitter CSR and
transmitter data,
A curiousity is that the Inmos Trnaputer link ionterface chip (C011) has
a similar programming itnerface too...
is a subset of the VAX console: the status bits that
both machines have
have the same values in their registers, and the VAX MTPR/MFPR
registers correspond 1:1 to the PDP-11 SLU registers (the PR numbers
are even in the same order as the PDP-11 addresses). So if there's a
chip designed for a PDP-11 SLU, it may well be what the KA620 and/or
I beleive therere was, bit i was designed by DEC and is thus semi-custom.
It was used on soem of the QBUS SLUs (DLV11-J ?) to save board space.
KA630 uses.
None of the UART chips I am (even vaguely) familiar with, like the
8530, fit this description. However, a serial line such as the VAX
uses is not a complicated device; I could probably put one together
from discrete logic in no more than an hour or two. It could very well
You could. The first PDP11 SLU was the KL11 AFAIK. That is a dual-hieght
board fo TTL and does current loop only. It was used with a separate
(single height each) M105 address decoder and M782 interrupt controller.
The later DL11s were gernally quad cards includign the address decoder
and interrupt logic. They used a 40 pin dumb UART chip with TTL glue.
be just a small section of one of the custom chips
involved.
Indeed it might. I've not seen any prints of the MicroVaxen. Are they on
bitsavers?
-tony