Re: [TUHS] Spacewar at Bell Labs [ really paper tape readers and tangentially related things ]
15 Jan
2020
15 Jan
'20
10:46 p.m.
From: Clem Cole
So WD designs and builds a few LSI-11 as a sales demo
of what you could
do
...
he put it on the QBUS which DEC could not lock up because they did not
create it as WD had.
Wow! WD created the QBUS? Fascinating. I wonder if DEC made any changes to the
QBUS between the original demo WD boards and the first DEC ones? Are there any
documents about the WD original still extant, do you know?
(FWIW, it seems that whoever did the QBUS interrupt cycle had heard about the
metastability issues when using a flop to do the grant-passing arbitrations;
see here for more:
https://gunkies.org/wiki/Bus_Arbitration_on_the_Unibus_and_QBUS#QBUS_Interr…
DEC had previously bent themselves into knots trying to solve it on the UNIBUS:
https://gunkies.org/wiki/M782_Interrupt_Control#Revisions
so it would be interesting to know if it was WD or DEC who did the DIN thing to
get rid of it on the QBUS.)
Noel
16 Jan
16 Jan
12:35 a.m.
New subject: Spacewar at Bell Labs [ really paper tape readers and tangentially related things ]
On Wed, Jan 15, 2020 at 11:47 AM Noel Chiappa <jnc(a)mercury.lcs.mit.edu>
wrote:
Wow! WD created the QBUS? Fascinating. I wonder if DEC
made any changes to
the
QBUS between the original demo WD boards and the first DEC ones?
I can not say I know and I would suspect they peed on it in some manner,
that *was the DEC culture*. I've just sent a note to Mr. BI to see if he
knows and I'll pass back anything I learn if I do. Sounds like the sort of
thing they might have gotten changed before it was release.
Are there any documents about the WD original still
extant, do you know?
I'm pretty sure we had some stuff from WD at CMU, because CM* was made out
of a lot of them, and CMU did custom microcode so they could talk to the
capabilities and K.map HW. I remember seeing some prints with WD markings
on it, but I was not heavily involved other than working the new
distributed front-end which we did with LSI-11s.
Somebody from the CMU HW lab like Jim Teter might know, although he did the
11/40e for C.mmp, I'm not sure who was the microcode guru on CM* as that
was all happening as I was leaving. I sent a couple of emails to folks
like Danny Klein, Mike Liebensberger, and Tron McConnell. Danny and Mike
are SW folks, Tron was a EE/HW type but mostly worked on other stuff at
Mellon Institute in those days. But, IIRC, Tron was worked on a 3Mbit
Xerox board for the LSIs, so he might have had something. We all did some
stuff with CM* (Mike more than any of us). FWIW: Tron was (is) a bit of
packrat and if he ever had anything like that, he might still have it.
30 Jan
30 Jan
2:25 a.m.
New subject: Spacewar at Bell Labs [ really paper tape readers and tangentially related things ]
On Wed, 15 Jan 2020, Noel Chiappa wrote:
Wow! WD created the QBUS? Fascinating. I wonder if DEC
made any changes
to the QBUS between the original demo WD boards and the first DEC ones?
Are there any documents about the WD original still extant, do you know?
Which reminds me: I heard a story that DEC did not implement the Unibus as
specified, in order to lock out 3rd-party vendors; apparently the timing
was not quite right. You couldn't complain to DEC because it was not
their gear, and you couldn't complain to the vendor because they followed
the spec...
-- Dave
1788
days inactive
1802
days old
2 comments
3 participants
participants (3)
-
Clem Cole -
Dave Horsfall -
jnc＠mercury.lcs.mit.edu