Our group here in NJ + surroundings now has monthly-ish repair workshops
(vs. a few times per year before). At the workshop this past weekend,
David Gesswein continued restoring our PDP-8.
David summarized: "I fixed the known fault of accumulator bit
going to zero when it was rotated left. This was a bad diode on one
of the accumulator boards. I also replaced two bad bulbs and a third
that died during the repair. Since one that died was one I previously
replaced I'm going to use the not quite matching bulbs with heavier
wires for future repairs. The wires are just too thinn on the 1762 bulbs
and now that they have aged they break too easy. I then found that the
teletype interface wasn't working and replaced a diode on a R220 to fix
output. Input is not working properly. I have traced it to a particular
flip flop on a R220 where when the data changes it feeds through to the
output without the clock active. I ran out of time to identify the
component that needs replacing."
Here's a little video of the computer chasing its lights. :)
http://www.vcfed.org/evan/pdp8lights.mp4
>Ulrich Tagge wrote:Hi Glen,
> [Snip]
>
> List/change parameters in the Setup table
>
> A - ANSI Video terminal (1) 0=No, 1=Yes = 1
> B - Power up 0=Dialog, (1)=Automatic, 2=ODT, 3=24 = 1
> C - Restart 0=Dialog, (1)=Automatic, 2=ODT, 3=24 = 1
> D - Ignore battery 0=No, 1=Yes = 0
> E - PMG 0-(7) 1=.4us, 2=.8, 3=1.6, 4=3.2,...7=25.6 = 7
> F - Disable clock CSR 0=No, 1=Yes = 0
> G - Force clock interrupts 0=No, 1=Yes = 0
> H - Clock 0=Power supply, 1=50Hz, 2=60Hz, 3=800Hz = 1
Does anyone have an idea as to how the choice of the 800Hz
option was made?
I could understand 1000Hz or perhaps 1200Hz which allows
division by both 50 and 60. But 800Hz seems like such an
unlikely value.
On the other hand, on the PRO350, the clock rate was 64Hz
and every 16 ticks, I assume that one tick was discarded so
as to support the appearance of a 60 Hz clock.
Jerome Fine
I successfully imaged OS revs E0, F0, F1, G0 and H0 of the Pascal
Microengine from the original
distribution media this morning with the application of cyclomethicone
as Chuck suggested. I
was worried since they were 79'ish vintage BASF media, but the
lubrication did the trick and
they read without errors.
http://bitsavers.org/bits/WesternDigital/microengine_distributions_E0-H0.zip
THAT IS WHAT WE USED TO CALL THE CYLON EYE PROGRAM!
eD# _WWW.SMECC.ORG_ (http://www.SMECC.ORG)
In a message dated 2/2/2016 1:27:02 P.M. US Mountain Standard Time,
cctalk at snarc.net writes:
Our group here in NJ + surroundings now has monthly-ish repair workshops
(vs. a few times per year before). At the workshop this past weekend,
David Gesswein continued restoring our PDP-8.
David summarized: "I fixed the known fault of accumulator bit
going to zero when it was rotated left. This was a bad diode on one
of the accumulator boards. I also replaced two bad bulbs and a third
that died during the repair. Since one that died was one I previously
replaced I'm going to use the not quite matching bulbs with heavier
wires for future repairs. The wires are just too thinn on the 1762 bulbs
and now that they have aged they break too easy. I then found that the
teletype interface wasn't working and replaced a diode on a R220 to fix
output. Input is not working properly. I have traced it to a particular
flip flop on a R220 where when the data changes it feeds through to the
output without the clock active. I ran out of time to identify the
component that needs replacing."
Here's a little video of the computer chasing its lights. :)
http://www.vcfed.org/evan/pdp8lights.mp4
Hi List,
I have a working 11/84, and I have decidec, to test some of my spare
cards, starting with: KDJ11-B.
I see the following error, when powering up the system, which points me
to the Clock.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Error 61
M8190 clock Error
See troubleshooting documentation
Command Description
1 Rerun test
2 Loop on test
Type a command then press the RETURN key:
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Any hints, what the problem could be? Is the clock in this new PDP's
still generated out of the line frequency? Could it by, that the KDJ11-B
is configured to a wrong HZ value?
Many Greetings
Ulrich
While browsing various 8 inch floppies I have found a couple of disks that
seems to contain ISIS-II stuff.
I discovered a document specifying the format of the disk and managed to
extract the contents:
Disk1:
arbetsrumsdatorn:ISIS mattis_lind$ ls UNKN2
ATTRIB DSPERR ICE80.OV1 ISIS.LAB PLM80.OV0 PLMCOD.CSD
COPY EDIT ICE80.OV2 ISIS.MAP PLM80.OV1 PLMNOC.CSD
DELETE FORMAT ISIS.BIN ISIS.T0 PLM80.OV2 RENAME
DIR ICE80 ISIS.CLI PLM80 PLM80.OV3 SUBMIT
DSP ICE80.OV0 ISIS.DIR PLM80.LIB PLM80.OV4 SYSTEM.LIB
Disk2:
arbetsrumsdatorn:ISIS mattis_lind$ ls DISK2
ALIAS DEBUG EXEC LINK RELEAS TTY
ALLOC DELETE FORMAT MDUP REMAP TXT
ANALYZ DGEN FRAPP MEMDMP RENAME TXW
ASM DIR HEXBIN MOVE RESCUE XREF
ASSIGN DIRPAC INIT MYLOAD SEDIT
ATTRIB DROP ISIS.DIR O SYS
DCONVA DRSTC ISIS.ERR PAGE SYSTEM
DCOPY EDIT ISIS.LAB PROM T2
DDUMC ETX ISIS.MAP RASM TPGEN
If someone is interested in these I put them here:
http://www.datormuseum.se/documentation-software/isis-ii-floppy-disks
There were also a DSDD format on some disks which seemed a little bit
different. The ISIS.DIR used 32 byte entries rather than 16 byte entries
and the directory linkage block structure seemed to be different. I didn't
spend any time other than recognize the difference.
Is there any documentation that specify the various ISIS disk formats there
is?
/Mattis
> From: Dale H. Cook
> I have spare IDE drives for my 98SE laptops.
Might want to drag them out once a year and run them, to prevent anything
sticking over time. (I should take my own advice, here.... :-)
Noel
On Sun, 31 Jan 2016, Pete Lancashire wrote:
>> On Sun, Jan 31, 2016 at 1:24 AM, Henk Gooijen <henk.gooijen at hotmail.com> wrote:
>>
>> Spend the extra few dollars (or what your currency is) and pack it in a
>> very strong box. I've actually had EPROMs show up cracked in half
>
>Seconded. The machines the USPS uses for automated sorting of mail are not
>gentle on parcels.
>
I'd rather strongly suggest you not us the USPS period. In the last 6
months or so they've flat out lost 4 items either destined to or
shipped by me, and one item apparently (according to the tracking web
site) sat in a sorting facility in Utah for nearly a month before
magically showing up. Glad it wasn't perishable.
KJ
While I was reading through the HP 200/300 BASIC Manual I came across some
interesting points I hadn't considered in the past.
I thought HP manuals were dry and hard to read, but I was wrong. See for
yourself...
Installing, Using, and Maintaining the BASIC 5.0 System
=============================================
Loading BASIC, page 1-16
-------------------------------
If You See Nothing on the Monitor Screen
Here are some possible explanations:
- The monitor's brightness is not turned all the way up.
- The monitor is not plugged in.
- The computer is not plugged in.
- Your eyes are not pointed in the right direction, or are obscured by your
eyelids.
Other Maintenance Tasks, page 17-1
--------------------------------------------
The following list mentions some things users take for granted or tend to
forget.
...
- ...
- ...
- Rotate your tires and otherwise examine your system to see that it is
performing nicely.
Maybe the author had a good friend in final quality control of the manuals.
Martin