Image Map Image Map
Results 1 to 10 of 10

Thread: Pdp-11/23

  1. #1

    Default Pdp-11/23

    I found a vintage DEC PDP-11 system that I'm interested in purchasing. It has a model # of 11C23-H, which I believe is a PDP-11/23 Qbus system. It also says "Micro PDP-11" on the section w/ the power button and other function buttons. It has a hard drive and a tape drive. But on the back it dose not have any serial ports, it has what looks like the AT style keyboard connections(maybe old audio ports). The price seems a bit high for the condition its in.

    Here is a link to the listing: https://www.ebay.com/itm/Digital-Mic...53.m1438.l2649

    Let me know what you think?

  2. #2

    Default

    I agree the price is too high. You're bound to find something more reasonable if you wait a bit. I have a nice 11/84 that I would like to sell. I can no longer
    lift it so it needs to go. Has a nice UC17 SCSI interface and a UDA50. Full 4MW memory. I run RSTS and Unix on it. I am in Colorado right now. Will be
    moving to Texas in Feb. Plan a trip to the east coast sometime May/Jun to the eastern Pa area.

  3. #3
    Join Date
    Jan 2010
    Location
    Central VA
    Posts
    4,093

    Default

    Yeah, price is high on that 11/23. That breakout panel with the DIN-looking connectors is probably some custom breakout for the serial console.

  4. #4

    Default

    The CPU board shown is not an 11/23 CPU, it is a KDJ11-Bx board so possibly an 11/73. It is in the 3rd slot, so maybe it is an 11/83 that has lost its PMI RAM boards. Can't really see what other boards are in the backplane.

  5. #5
    Join Date
    Feb 2011
    Location
    Salisbury Maryland
    Posts
    752

    Default

    Way too much for what’s there, its not a 23 or a 23+ , the TK drive is no prize and its missing the case. Wild speculation but almost looks like someone took a Microvax frame and stuffed cards in it to build some form of an eleven. Certain several people on here have more for sale for less if you want one.
    If there was a clear view of the power switch you can see if it was a MicroVax or a real PDP-11, not that this is an issue being later elevens came in the same frame.

  6. #6

    Default

    Actually, the label on the back of the BA23 says it originally was an 11C23-H (3rd photo). The power switch can be seen well enough in the 5th photo to see that it says "Micro PDP-11". But who can tell what is in the box and whether or not it runs? I suspect this will sell at a lower price.

  7. #7
    Join Date
    Jan 2010
    Location
    Central VA
    Posts
    4,093

    Default

    Yeah, that's a totally appropriate chassis for a MicroPDP series PDP-11. My MicoPDP-11/73 is in a similar chassis, with the deskside pedistal stand enclosure. You could install the same basic enclosure in a rack mount as well. The badge orientation suggests it was in fact rack mounted.

    With the RD52, TK50, and KDJ11, it is in fact almost the exact same factory configuration that my MicroPDP-11/73 came with. It could be an 11/53 or 11/83. With a configuration like that, if it was demonstrated to be actually working, it'd probably be worth around $1000, at least on eBay. But, yeah, who knows what its operational condition is.

  8. #8
    Join Date
    Feb 2011
    Location
    Salisbury Maryland
    Posts
    752

    Default

    Yea I know that’s the same frame and power supply as the 11/53,73 or 83 but not a 11/23. noticed after I saw the post that it says PDP-11 on the power switch and the card in the system looks like a 53/73 but no way is it a 11/23, also no matter how you look at it the TK-50 is still a dog. If you want a basic 11/23 you can do better for less.

  9. #9

    Default

    Agreed that the price is not good for what is offered.

    But your assertion that DEC never sold 11/23 systems in BA23 boxes is plain wrong. For example, see ED-25116-18_PDP-11_Systems_and_Options_Catalog_Jul83.pdf, especially pages 1-7 (page 27 of the pdf) through 1-9. The later DCJ11-based CPUs did not exist at the time, so all Micro PDP-11 systems at that time were, in fact, 11/23 systems. As shown in the catalog, the CPU used at that time was a KDF11-BE, listed as a "11/23-PLUS
    CPU".

    The sticker on the back of the system in the ebay photos shows a packaged system designation of 11C23-H, but that must have been from a later catalog than the one I could find on BitSavers.

    I think you will find that the BA23 was first shipped with the Micro PDP-11 product line because the first MicroVAX products were not released until 1984.
    Last edited by Uniballer; September 3rd, 2018 at 02:11 PM.

  10. #10

    Default

    Yeah, my 11 started life as an 11/23 in a BA-23.
    Computers: Amiga 1200, DEC VAXStation 4000/60, DEC MicroPDP-11/73
    Synthesizers: Roland JX-10/SH-09/MT-32/D-50, Yamaha DX7-II/V50/TX7/TG33/FB-01, Korg MS-20 Mini/ARP Odyssey/DW-8000/X5DR, Ensoniq SQ-80, E-mu Proteus/2, Moog Satellite, Oberheim SEM
    "'Legacy code' often differs from its suggested alternative by actually working and scaling." - Bjarne Stroustrup

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •