Image Map Image Map
  • jackrubin's Avatar
    Today, 05:32 AM
    jackrubin replied to a thread Unknown DEC Part in DEC
    Shipping for just the backplane shouldn't be too bad - small items below 4 pounds can go relatively reasonably by USPS First Class International.
    7 replies | 145 view(s)
  • jackrubin's Avatar
    Yesterday, 07:01 PM
    jackrubin replied to a thread Extended Bootloader Blues in DEC
    Well, the ghost came back, but I think it is now well and truly squashed. Earlier this week, the Computerarium was honored with a visit from a...
    20 replies | 748 view(s)
  • jackrubin's Avatar
    Yesterday, 06:49 AM
    I'm soldering in my sockets, but then I'm a belt-and-suspenders kind of guy.
    162 replies | 13820 view(s)
  • MattisLind's Avatar
    July 18th, 2019, 08:34 AM
    There was an ad on a Norwegian ad site site for a old computer. An ICL PERQ. It was only 75 USD so I got a friend of mine in Oslo purchase it and...
    2 replies | 53 view(s)
  • MattisLind's Avatar
    July 18th, 2019, 08:20 AM
    The horisontal scan frequency of the original HP 35731 monitor is 24.9 - 25.8 kHz. Does your Zenith cope with that? Look here for more...
    2 replies | 43 view(s)
  • m_thompson's Avatar
    July 14th, 2019, 09:06 AM
    m_thompson replied to a thread New to me PDP-11/53 in DEC
    That is the CPU that I have. The Dataram board has 4x columns of 18 RAM chips. The RAM chips are Micron 1259-12, so that makes it 1MW with parity...
    7 replies | 289 view(s)
  • m_thompson's Avatar
    July 14th, 2019, 06:25 AM
    You can find the manuals for the 8/e here: http://www.bitsavers.org/pdf/dec/pdp8/pdp8e/ You can start by removing all of the boards and testing...
    1 replies | 106 view(s)
  • m_thompson's Avatar
    July 14th, 2019, 06:18 AM
    m_thompson replied to a thread PDP-9 at the RICM in DEC
    Too many visitors yesterday to get much done on the TC02. We are still getting the END error after we send a MOVE command to the TC02 and the tape...
    62 replies | 7820 view(s)
  • m_thompson's Avatar
    July 11th, 2019, 03:08 PM
    Vincent made replacement switch and lamp PCBs for the 8/I. http://so-much-stuff.com/pdp8/frontpanel/frontpanel.php
    162 replies | 13820 view(s)
  • MattisLind's Avatar
    July 8th, 2019, 01:41 AM
    Here is the scan: http://storage.datormuseum.se/u/96935524/Datormusuem/DEC/MAINDEC-08-DIVTC-A-D_VT55_ACCEPTANCE_TEST.pdf Add the binary later on....
    13 replies | 716 view(s)
  • m_thompson's Avatar
    July 7th, 2019, 04:48 PM
    m_thompson replied to a thread PDP-9 at the RICM in DEC
    We replaced a defective S107 inverter FlipFlop. The control signals to the TU55 DECtape look better, but we are still getting the END error and the...
    62 replies | 7820 view(s)
  • m_thompson's Avatar
    July 7th, 2019, 05:31 AM
    m_thompson replied to a thread PDP-9 at the RICM in DEC
    We tried to control the TU55s through the controller. If we command the drive to move, it moves about 1mm, stops, and shows an END error. It thinks...
    62 replies | 7820 view(s)
  • m_thompson's Avatar
    July 7th, 2019, 05:21 AM
    m_thompson replied to a thread New to me PDP-11/53 in DEC
    How do I tell which version I have? I have an Emulex UC07 Dual-SCSI that I could use. I should have more memory boards too. I need to...
    7 replies | 289 view(s)
  • jackrubin's Avatar
    July 6th, 2019, 01:54 PM
    jackrubin replied to a thread New to me PDP-11/53 in DEC
    Mike - be careful with that QBUS stuff - it just works.
    7 replies | 289 view(s)
  • jackrubin's Avatar
    July 6th, 2019, 12:37 PM
    jackrubin replied to a thread Extended Bootloader Blues in DEC
    @Roland - Mike Zahorik seems to be using a combo board without any problems, but I don't know his exact setup. I certainly understand the long trace...
    20 replies | 748 view(s)
  • m_thompson's Avatar
    July 6th, 2019, 07:20 AM
    m_thompson started a thread New to me PDP-11/53 in DEC
    I picked up a BA23 based PDP-11/53 yesterday that I removed from an Ultratech wafer stepper system. It lived all of its life in a clean room, so...
    7 replies | 289 view(s)
  • m_thompson's Avatar
    July 6th, 2019, 05:30 AM
    This will help: http://www.ultimate.com/phil/pdp10/dec.disks The manual for the RF09 for the PDP-9 was first printed in July of July of 1970, so...
    5 replies | 192 view(s)
  • jackrubin's Avatar
    July 5th, 2019, 03:35 PM
    jackrubin replied to a thread Extended Bootloader Blues in DEC
    C10 is in place on both boards and didn't seem to stop the glitching. I installed the filter cap (across R_SW, not SW_RUN as I first wrote) directly...
    20 replies | 748 view(s)
  • jackrubin's Avatar
    July 5th, 2019, 03:34 PM
    jackrubin replied to a thread Extended Bootloader Blues in DEC
    I just tried the first (unmodified) Boot+Mem card with the machine closed (no cover) and the lab lights off. It ran the Accumulator Increment test...
    20 replies | 748 view(s)
  • jackrubin's Avatar
    July 5th, 2019, 02:23 PM
    jackrubin replied to a thread Extended Bootloader Blues in DEC
    I just shut the machine off - Accumulator Increment ran for over 1 1/2 hours.
    20 replies | 748 view(s)
  • jackrubin's Avatar
    July 5th, 2019, 01:38 PM
    jackrubin replied to a thread Extended Bootloader Blues in DEC
    At Roland's suggestion, I installed a 1 uF capacitor between pin 15 (SW_RUN) and pin 8 (GND) on the Atmega to reduce the chance of EMI glitches. I...
    20 replies | 748 view(s)
  • jackrubin's Avatar
    July 5th, 2019, 07:25 AM
    jackrubin replied to a thread Extended Bootloader Blues in DEC
    Moving along slowly, I built my second Mem+Bootloader card last week and brought it out to the Computerarium for testing. It exhibited the same...
    20 replies | 748 view(s)
  • MattisLind's Avatar
    July 5th, 2019, 12:27 AM
    Good work getting the 4907 working and a really nice 4054! I would like to somehow emulate the 4907. Did you do any work on this or is it me...
    14 replies | 331 view(s)
  • m_thompson's Avatar
    July 3rd, 2019, 09:17 AM
    You have an early 8/e. On the later ones the first switch position is at about 11:00 and the last at about 7:00.
    4 replies | 107 view(s)
  • m_thompson's Avatar
    July 3rd, 2019, 03:35 AM
    There have been several sold on eBay recently, but they were quite expensive.
    1 replies | 94 view(s)
  • jackrubin's Avatar
    July 2nd, 2019, 03:42 PM
    jackrubin replied to a thread Atex PDP-11/34 in DEC
    Nick, Is the machine in San Jose or Vancouver? If it's in San Jose and you haven't made much progress over the next few weeks, why not bring...
    24 replies | 888 view(s)
  • m_thompson's Avatar
    July 2nd, 2019, 03:46 AM
    m_thompson replied to a thread what switch panel is this? in DEC
    It might be from a PDP-8a. The third LED is for Battery Charge.
    9 replies | 357 view(s)
  • m_thompson's Avatar
    July 1st, 2019, 12:41 PM
    m_thompson replied to a thread PDP-9 at the RICM in DEC
    Several of the Margin Power switches were on, and we didn't have the Margin Power Supply cable installed, so there were unpowered sections of the...
    62 replies | 7820 view(s)
  • jackrubin's Avatar
    June 30th, 2019, 06:12 AM
    I'm pretty sure daver2 already pointed to them, but they're buried in the old N8VEM wiki -...
    162 replies | 13820 view(s)
  • MattisLind's Avatar
    June 30th, 2019, 04:04 AM
    I have a PDP-8 Maindec. VT55 acceptance test. Both paper tape and listing. http://www.datormuseum.se/documentation-software/paper-tapes I can...
    13 replies | 716 view(s)
More Activity
About m_thompson

Basic Information

About m_thompson
Biography:
Volunteer at the RICM. Working on a PDP-12, PDP-8/I, 8/L, 8/e, PDP-9, 11/34a, and 11/44.
Location:
Rhode Island
Interests:
Vintage minicomputers.
Occupation:
Engineer

Signature


Member of the Rhode Island Computer Museum
http://www.ricomputermuseum.org

Statistics


Total Posts
Total Posts
1,147
Posts Per Day
0.62
General Information
Last Activity
July 18th, 2019 03:46 PM
Join Date
July 8th, 2014
Referrals
0

3 Friends

  1. jackrubin jackrubin is offline

    Senior Member

    jackrubin
  2. MattisLind MattisLind is offline

    Senior Member

    MattisLind
  3. mu301 mu301 is offline

    Junior Member

    mu301
Showing Friends 1 to 3 of 3