1 Mar
2005
1 Mar
'05
10:53 p.m.
The PDP-1 Restoration Project is still far from complete, but we hit
a major milestone tonight. When we last tried to run Spacewar,
the sun and player ships would not display correctly, though the
starfield and torpedos seemed to be fine. We ran the DEC instruction
diagnostics and they failed on the shift/rotate test, though all
the diagnostics had passed a few months earlier.
This week we wrote a more specific diagnostic program and determined
that left shifts and rotates of the I/O register were not doing anything,
though right shifts and rotates of the I/O register were fine, and all
shifts and rotates of the accumulator were fine. After a little study of
the print set, we identified two system modules that could cause the
observed behavior. We tried replacing one of them, a 1607 pulse amplifier.
After replacing the 1607, our own diagnostic and the DEC diagnostic
both passed. Some of the team wanted to go home without trying out
Spacewar, but the rest of us nagged until they gave in. We loaded it,
and it ran correctly.
Spacewar on the real Type 30 display with long persistence phosphor
is a thing of beauty!
Some of the tasks remaining to be done:
* build new Spacewar control boxes
* continue repair/testing of Soroban console typewriter
* adjust Type 30 display to factory specs (linearity is poor)
* adjust paper tape reader sensitivity/threshold
* diagnose & repair suspected flaky memory "module" 0
* voltage margin checks, run all diagnostics
* install new belt and test BRPE tape punch
Eric
1 Mar
1 Mar
11:59 p.m.
It was indeed thrilling to play Spacewar tonight on the PDP-1 - although I
have to admit I was one of the team members who wanted to stop at the very
positive note of having fixed the left shift/rotate bug - It was getting late
and I was worried that Spacewar wouldn't run - and we'd have to leave tonight
feeling slightly discouraged...
I had played Spacewar in the early sixties at Stanford University and many
years later (in the mid-70's) I ran Spacewar on my own PDP-12. But seeing it
run tonight on the PDP-1 was amazing and exciting - a forty year old machine
playing a spacewar game on a persistance-seven-screen was a sight to see and
a great experience to feel!!!!! It, for sure, makes all the hours of labor
and TLC spent on the PDP-1 worth it :-)
Lyle
On Tuesday 01 March 2005 22:53, Eric Smith wrote:
The PDP-1 Restoration Project is still far from
complete, but we hit
a major milestone tonight. When we last tried to run Spacewar,
the sun and player ships would not display correctly, though the
starfield and torpedos seemed to be fine. We ran the DEC instruction
diagnostics and they failed on the shift/rotate test, though all
the diagnostics had passed a few months earlier.
This week we wrote a more specific diagnostic program and determined
that left shifts and rotates of the I/O register were not doing anything,
though right shifts and rotates of the I/O register were fine, and all
shifts and rotates of the accumulator were fine. After a little study of
the print set, we identified two system modules that could cause the
observed behavior. We tried replacing one of them, a 1607 pulse amplifier.
After replacing the 1607, our own diagnostic and the DEC diagnostic
both passed. Some of the team wanted to go home without trying out
Spacewar, but the rest of us nagged until they gave in. We loaded it,
and it ran correctly.
Spacewar on the real Type 30 display with long persistence phosphor
is a thing of beauty!
Some of the tasks remaining to be done:
* build new Spacewar control boxes
* continue repair/testing of Soroban console typewriter
* adjust Type 30 display to factory specs (linearity is poor)
* adjust paper tape reader sensitivity/threshold
* diagnose & repair suspected flaky memory "module" 0
* voltage margin checks, run all diagnostics
* install new belt and test BRPE tape punch
Eric
--
Lyle Bickley
Bickley Consulting West Inc.
http://bickleywest.com
"Black holes are where God is dividing by zero"
2 Mar
2 Mar
11:15 a.m.
On Tue, 1 Mar 2005, Eric Smith wrote:
After replacing the 1607, our own diagnostic and the
DEC diagnostic
both passed. Some of the team wanted to go home without trying out
Spacewar, but the rest of us nagged until they gave in. We loaded it,
and it ran correctly.
Spacewar on the real Type 30 display with long persistence phosphor
is a thing of beauty!
Congratulations!
2:06 p.m.
Tom Jennings wrote:
On Tue, 1 Mar 2005, Eric Smith wrote:
Same here. Now we all need a nice photo of it action.
Ben alias woodelf
After replacing the 1607, our own diagnostic and
the DEC diagnostic
both passed. Some of the team wanted to go home without trying out
Spacewar, but the rest of us nagged until they gave in. We loaded it,
and it ran correctly.
Spacewar on the real Type 30 display with long persistence phosphor
is a thing of beauty!
Congratulations! 
3 Mar
3 Mar
4:37 p.m.
On Wed, 2005-03-02 at 15:06 -0700, woodelf wrote:
Tom Jennings wrote:
That's just amazing... congratulations!
I'll come someday. Again, congratulations, and keep up the excellent
work!! If I had half the skills you guys have, the PDP-7 would be
calculating primes by now :)
--
Tore S Bekkedal <toresbe at ifi.uio.no>
On Tue, 1 Mar 2005, Eric Smith wrote:
Same here. Now we all need a nice
photo of it action.
Ben alias woodelf Spacewar on the real Type 30 display with long
persistence phosphor
is a thing of beauty!
Congratulations!
5 p.m.
Tore replied to my message about the PDP-1 finally running
Spacewar successfully:
I'll come someday. Again, congratulations, and
keep up the excellent
work!! If I had half the skills you guys have, the PDP-7 would be
calculating primes by now :)
Although I don't want to downplay the skills of any of the team
members, the main thing that was required was a lot of hours of
volunteer effort. I'm not sure of the current total but I think it's
well over 1000 volunteer-hours. If you had that much time available
you'd probably have the PDP-7 working.
Eric
6 p.m.
We should have the actual number of hour when the CHM issues their "volunteer"
hour awards. But my guess is: 3-3.5 hours per person (6-7) per week for one
year is about 1,250 hours - and the project has been active for over a year!
I also think there is a lot of serendipity that occurs when you have a group
of folks who have varied skill sets in restoration working as a team. I'm
confident that none of the individual team members could have made the
progress that we made as a team - even if that individual dedicated the full
1,250 man hours to the project. (And we all think we are GOOD ;-)
Lyle
On Thursday 03 March 2005 17:00, Eric Smith wrote:
Tore replied to my message about the PDP-1 finally
running
Spacewar successfully:
--
Lyle Bickley
Bickley Consulting West Inc.
http://bickleywest.com
"Black holes are where God is dividing by zero"
I'll come someday. Again, congratulations,
and keep up the excellent
work!! If I had half the skills you guys have, the PDP-7 would be
calculating primes by now :)
Although I don't want to downplay the skills of any of the team
members, the main thing that was required was a lot of hours of
volunteer effort. I'm not sure of the current total but I think it's
well over 1000 volunteer-hours. If you had that much time available
you'd probably have the PDP-7 working.
Eric
7234
days inactive
7236
days old
6 comments
5 participants
participants (5)
-
bfranchuk＠jetnet.ab.ca -
eric＠brouhaha.com -
lbickley＠bickleywest.com -
tomj＠wps.com -
toresbe＠ifi.uio.no