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Thread: can anybody identify this old disk drive and/or tape drive?

  1. #1

    Default can anybody identify this old disk drive and/or tape drive?

    I can get lots more photos if it might help somebody.
    This disk unit is part of a large pdp8/i rack. Fixed disk, 19" rack mounting about 8" in total height. The disk containing cylinder is LIKE that of a RS03/04 - about 16" in diameter and perhaps 4" high.
    Very little on it by way of labels (that are readable). I have not opened the unit yet - nor gone looking for circuit board names etc.

    All clues welcome:
    IMG_20191127_202618.jpg
    I can tell this is an IBM spool on the tape drive, any more clues?
    IMG_20191127_202653.jpg
    The front panel:
    IMG_20191127_202550.jpg

    All clues welcome?

  2. #2
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    I would like more pictures. British repackaging of early DEC hardware? Guessing that from the use of "disc" on the label. Seems likely to have an interesting story behind it.

    The tape drive looks to be a 9-track model but one from before anything I have worked with. I think I have seen a picture of that exact drive previously but I can't remember where or a model number.

    Given the apparent age of the tape drive, I would expect the drive would be something like the DF32 i.e. amongst the first drives DEC offered or a third party equivalent. But that is guesses on top of guesses and very likely to be wrong.

  3. #3
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    Is the disk manufactured by Data Disc Inc or possibly Scientific control corp?

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    Quote Originally Posted by iainmaoileoin View Post
    I can get lots more photos if it might help somebody.
    This disk unit is part of a large pdp8/i rack. Fixed disk, 19" rack mounting about 8" in total height. The disk containing cylinder is LIKE that of a RS03/04 - about 16" in diameter and perhaps 4" high.
    Very little on it by way of labels (that are readable). I have not opened the unit yet - nor gone looking for circuit board names etc.

    data disc 7200, ca. 1972

    kennedy tape drive. count the heads to see if it's 7 or 9 or look at the part number tag on the back
    it's probably a model 3112 read after write model

  5. #5

    Default mair photos

    I was in the bunker tonight, dug oot ra disks and got youz mair photos:
    IMG_20191128_181444.jpg
    IMG_20191128_181414.jpg
    IMG_20191128_181454.jpg
    IMG_20191128_181425.jpg
    IMG_20191128_181737.jpg
    IMG_20191128_181728.jpg

    krebizfan I did not spot the spelling of DISC this kit came to me from the States - not from the UK - I see the mfr is in palo alto. So indeed the name is strange. When I started Uni (Scotland) disc was the common spelling of what is now disk.

    Al + PG31 spot on. Will there be any manuals on bitsavers I wonder?
    What capacity are they on the erb I find "Data Storage - this system is to provide mass storage for the con* densed data streams emanating from the Patient Computers. The initial system is composed of a PDP-8L to serve as a data buffer and controller for two Data Disc 7206 magnetic disc memories with a storage capacity of 12.6 mega BITS". 6.3 mega BITS per disk? being about 800Kbytes or 500K pdp8 words?

    Do you think I should ever apply power to these - or will the magic smoke appear and ruin the kit forever ;-(

    The controller for the 4 drives is here:
    IMG_20191128_181643.jpg
    IMG_20191128_181700.jpg

  6. #6

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    I found this in a 1970s report on the web
    "A disc-oriented system has been constructed for mass data storage and retrieval to aid on-line evaluation of the Argus algorithms. A fixed* head, 64-track, 6.4 megabit disc (Data Disc 7206) was interfaced to an 8K, 1.6 VB processor (DEC PDP-8L) via the single-cycle data break channel. Each disc track contains 32 blocks of 256 thirteen-bit words (twelve data bits plus parity), providing a total disc capacity of 2048 blocks, the equivalent of four standard LINC tapes.

    An lOT instruction initiates reading or writing of one block of disc data whose address is specified by the contents of the PDP-8 accumulator (0-3777(base)' A separate lOT instruction is used to set the initial data transfer core location (modulo400(base). A program interrupt is generated upon completion of disc transfer and additional lOT instructions test for parity error and transfer comple* tion. Worst case access time for a block of data is 33.3 ms and the transfer time is 1,024

    The maximum attainable data transfer rate is 16 blocks in 33.3 ms and occurs when requested block addresses are sequentially increased by two (modulo 40(base )' In order to allow concurrent processing and disc transfer, the interface contains a four-word circular buffer between disc and core memory. This buffer allows operation under worst case conditions when a data break request occurs shortly after the beginning of an lOT instruction which is followed by a memory reference instruction with indirect addressing."
    Washington University 1971 Progress Report No. 7 Biomedical Computer Laboratory

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