18 Sep
2015
18 Sep
'15
2:42 p.m.
On 2015-09-18 18:21, Jon Elson wrote:
On 09/18/2015 08:45 AM, tony duell wrote:
The 11/780 has a PDP11 to load the microcode
(I think) but the 11/730
makes do with an
8085. After booting I think that handles the console port still.
-tony
780's had a board of fixed microcode, and then a WCS board was added in
later revisions (and all machines in the field had to be upgraded) to
add some additional code to handle added instructions used by the OS (at
least for VMS, don't know if BSD used it). The WCS microcode was in a
file on the LSI-11's floppy, and it was called in at a certain point of
the VMS boot sequence. That caused a line to print during the boot.
The typical dot matrix printer console on the 780 was also connected
to/through the LSI-11.
The normal WCS option for the 11/780 was an option. Not everyone had it.
Were there another option with some WCS that actually everybody had?
Johnny
As far as I know, the VAX11/730 (There is one next to
me waiting for
me to have time
to restore it) has the microcode entirely in RAM. Classic PERQs (3
in the next room) have
The PDP-11 console loads the microcode from disk then
mostly just
sits there
looking pretty whilst the VAX runs.