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Recent content by Old Computers

  1. O

    Maintenance Documentation Service

    I ordered a part for my PDP-11 and the seller included two sets of CDs titled: "Maintenance Documentation Service on CD-ROM". The only issue is that the CD-ROM sets are formatted for openVMS and the search program included is for openVMS. Windows nor Linux (Ubuntu) recognize the disks. I did...
  2. O

    PDP-11/44 Restoration (part 2)

    After having put this project on a long hiatus I have finally decided to try and finish up my PDP-11/44 restoration. So a quick recap of what was being done: The system would initially not turn on. A capacitor was replaced on the Bias and Interface board, and then the system would power on...
  3. O

    Apple II plus issue

    I did go ahead and replace B10 with a new chip and that did not appear to do anything. I also shorted out the two pins mentioned earlier, the text got messed up on the screen but nothing else happened the scrolling effect was not there. As for the Applesoft issue I am completely unable to...
  4. O

    Apple II plus issue

    I took a picture of the screen after pins 3 and 4 were briefly shorted on B2. The appearance of the screen slightly changes over time, and the beeping is still the same pattern that is present at start-up. The chip that gets warm is B1, not B2. Based on my IR thermometer it reads about 90...
  5. O

    Apple II plus issue

    I just checked pins 2,4, 6, and 40. They all read about 5.8-6V. I used the metal base of the computer for the ground, and I also used the ground part of the video connector and the voltages all read the same using both. Is having that high of a voltage something to be concerned of? I also...
  6. O

    Apple II plus issue

    I just double checked the ROMs and according to the chart I found, the chips all appear to be in their correct places. There does not appear to be any heavy oxidation on the ROMs' pins. Here is the order of the ROMs in my system: F8: 341-0020 F0: 341-0015-00 E8: 341-0014-00 E0: 341-0013-00 D8...
  7. O

    Apple II plus issue

    I recently acquired an Apple II plus with a few cards. When I proceeded to power it up, the display was all ?'s and it kept beeping. The pattern of beeping was the typical start up beep, then several beeps very close together (it almost sounded like a continuous tone), and then it would...
  8. O

    Heathkit Octoport Troubleshooting

    I recently purchased a piece of equipment called Heathkit Octoport. It is serial switch box that is software controlled and configurable. You send commands to it to link a serial port to another serial port, or link to one of the two parallel ports for printing. When I purchased it, the...
  9. O

    Qualstar 9 Track Tape Drive Take Up Reel

    I was using my tape drive today, and I stepped away for a moment. When I came back the tape had somehow come off of the transport, and a portion of it had wrapped itself around the spindle of the take-up reel. After removing the tape, the rubber ring around the take-up reel had come loose, and...
  10. O

    PC-Bubble Bubble Memory ISA Card

    Here is a picture of the board: Thanks for all the information about bubble memory. It is quite fascinating. And the card is still working. It has been about a week now and still doing just fine!
  11. O

    PC-Bubble Bubble Memory ISA Card

    I have recently obtained an Intel iPCB-76 PC-Bubble card. From the documents I have received with the card it appears to be the same as an iPCB-75 but with a BIOS extension for it to act as a fixed disk. After double checking the settings specified in the manual and the errata pages that came...
  12. O

    VIC-20 Issues

    I recently obtained a VIC-20, and I have found that the 2 key does not function at all, and that the 4 key displays the $ when pressed without the shift key. Also it will display 4 when the Commodore key is pressed with it. It also displays other characters at times. All the other keys work...
  13. O

    ALPS P200G Printer Error

    I have an ALPS P2000G dot matrix printer. When I turn it on it the error light flashes continuously and the internal speaker beeps 5 times. When I remove the interface cartridge there are no errors. Searching for this printer model online only produces links to stuff for sale for other ALPS...
  14. O

    DEC Rainbow HDD problem

    I recently acquired a DEC Rainbow computer, and it worked perfectly, including the hard drive. Today the computer froze, and I had to turn it off (the setup screen wouldn't even show up to do a reset). I did receive error message 16 Interrupts off, and another message regarding the main board...
  15. O

    Molecular Computers board

    A while back I started a thread (http://www.vintage-computer.com/vcforum/showthread.php?32921-Single-Board-Computers&highlight=single+board+computer) regarding a couple of single board computers. One of them has a brand name of Molecular computers, but I could find no information about it at...