Nagered hard drive;'(..

Discussion in 'Computer Information' started by tony sayer, Jun 22, 2010.

  1. tony sayer

    Bob Eager Guest

    Yes, I remember ours. There's a working one at Bletchley Park.
     
    Bob Eager, Jun 24, 2010
    #41
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  2. tony sayer

    Bob Eager Guest

    I used to have to USE 5 track paper tape.
     
    Bob Eager, Jun 24, 2010
    #42
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  3. tony sayer

    Bob Eager Guest

    The disks on the ICL 4130 at Kent were initially 2MB, latre upgrade to
    4MB. Alan Ibbetson and I hand punched a paper tape to patch the operating
    system...

    Think they were four platters, so 0.66MB per platter...
     
    Bob Eager, Jun 24, 2010
    #43
  4. tony sayer

    Tim Streater Guest

    Well it had to. The machine was too slow to read the tape continuously.

    The console had three mechanical buttons, only one of which was supposed
    to be latched down at any one time (you pressed another and it went
    down, and the first one popped up).

    Of course I pressed all three down - and guess what - I couldn't get
    them back up again. I think that involved a long service call but
    curiously I didn't get a wigging.
     
    Tim Streater, Jun 24, 2010
    #44
  5. tony sayer

    Tim Streater Guest

    I must see that next time I'm there.
     
    Tim Streater, Jun 24, 2010
    #45
  6. tony sayer

    Bob Eager Guest

    It's on the 803, strangely enough!
     
    Bob Eager, Jun 24, 2010
    #46
  7. tony sayer

    Bob Eager Guest

    Indeed. Which reminds me...I have two single-platter 10MB drives in my
    workshop that I need to get going - DEC RL02s...
     
    Bob Eager, Jun 24, 2010
    #47
  8. Just shows how little you ever really knew about anything.
     
    The Natural Philosopher, Jun 24, 2010
    #48
  9. My first machine had a tape drive, the twin 5 1/14" floppy disks were extra.
     
    The Natural Philosopher, Jun 24, 2010
    #49
  10. I remember drives that were sensitve to changes in orientation. My DVR
    claims to be sensitve to changes in orientation. My cable provider says the
    DVR won't work right if it's not laying flat. My last DVR had a sticker on
    it warning me that it absolutely must not be tilted or tipped -- the
    difference is lost on me, but the sticker was there.

    I remember that the HDD had to be set in the orientation it was to be used
    in, then formatted or the formatting would not work.
     
    Jeff Strickland, Jun 24, 2010
    #50
  11. tony sayer

    Roland Perry Guest

    There weren't many hard drives of the sort the public might buy, before
    then. If Jules was referring to ones you'd only find in a computer room,
    it wasn't an especially helpful remark to make to an end user.
    In mid 70's I worked on ICL drives, including something they called a
    "drum", which was a single-platter mounted vertically.

    My first programming (around 1968) was done on hand-punched cards, which
    I preferred to paper tape as it was both easier to edit and faster to
    create (I could hand-punch cards faster than the CPS of the teletype
    you'd use to make the paper tape).
    Somewhere I have an early "PROM", you programmed it by soldering diodes
    in, and the foot-square PCB probably has a couple of dozen bytes
    capacity.
     
    Roland Perry, Jun 25, 2010
    #51
  12. tony sayer

    Roland Perry Guest

    The first computer I owned - bought new and belonging entirely to me -
    in about 1975, was shipped as standard with 128bytes of memory (a 1kbit
    chip arranged 128x8). But I splashed out and bought two more, so I had
    384bytes to play with.
     
    Roland Perry, Jun 25, 2010
    #52
  13. tony sayer

    Roland Perry Guest

    In message <>, at
    By around 1981 I was the UK distributor for the Micropolis range of
    drives, which were originally in the same form factor as an 8" floppy
    drive. The most capacious was 33MB, and cost about the same a small
    family car.

    One of my customers was the BBC newsroom, who bought one to store
    digitised images to project behind the newsreader's head - to replace
    the infamously unreliable slide projector they used to have. In those
    days it was difficult to find people who thought they needed that much
    storage (outside of a classic mainframe scenario).
     
    Roland Perry, Jun 25, 2010
    #53
  14. tony sayer

    Roland Perry Guest

    In message <>, at
    Other way round, surely? It was a coding method to make sure you never
    had too many of the same polarity bits "in a row", which risks
    unreadability. What makes a magnetic storage medium work is *changes* in
    polarity.
     
    Roland Perry, Jun 25, 2010
    #54
  15. tony sayer

    Bob Eager Guest

    The important point about the ICL drum was that (like the real drums
    before it) it had one head for each track, thereby reducing the seek time
    to the electronic switching time. They were mainly used for paging, but I
    seem to recall that the ICL ones were let down by a sluggish transfer
    rate.
    Same here....my first three years (1970-73) were nearly all on punched
    cards. I still have a few as bookmarks!
     
    Bob Eager, Jun 25, 2010
    #55
  16. tony sayer

    Tim Streater Guest

    Sorry - I meant I must see the *803* when I'm next there.
     
    Tim Streater, Jun 25, 2010
    #56
  17. tony sayer

    Roland Perry Guest

    True, they didn't float over the surface, and that's one reason the
    capacity was poor.
    The ICL "drums" I worked on were actually discs.
    I was the runner who took the cards from school each day to the
    (different) college on my way home, and brought back the previous day's
    output. Talking to the operators, and being allowed into the computer
    room to help them, was one of the things that motivated me more than
    just the programming.
     
    Roland Perry, Jun 25, 2010
    #57
  18. tony sayer

    baron Guest

    Roland Perry Inscribed thus:
    Couldn't resist, :)
    I still have my first ever hard disk drive, purchased in 1983/4. It has
    four 5.25" platters and a linear stepper driven head. A whopping 5Mb.
    Well in was in those days ! It still functions, though its more of a
    showpiece nowadays.
     
    baron, Jun 25, 2010
    #58
  19. tony sayer

    baron Guest

    Andy Champ Inscribed thus:
    I would argue that that the speed has increased markedly simply because
    the storage density has improved dramatically. 15K spindle speeds and
    360Gb plus on a single platter. Add to that on board two way cache, on
    some drives 32Mb, means that the bottleneck is moving back to how fast
    the mainboard circuits can handle the data stream.
     
    baron, Jun 25, 2010
    #59
  20. tony sayer

    baron Guest

    [email protected] Inscribed thus:
    A similar "core" based memory was used in a "Seeburg" Jukebox to store
    record selections in the late fifties early sixties.
     
    baron, Jun 25, 2010
    #60
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