Re: ra disks - VMS

This is a discussion on Re: ra disks - VMS ; On Tue, 24 May 2005, Douglas A. Gwyn wrote: > Bill Gunshannon wrote: > > As long as you've brought it up, anybody have any RA7x or RA9x disks > > they don't need that they would like to donate ...

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Thread: Re: ra disks

  1. Re: ra disks

    On Tue, 24 May 2005, Douglas A. Gwyn wrote:

    > Bill Gunshannon wrote:
    > > As long as you've brought it up, anybody have any RA7x or RA9x disks
    > > they don't need that they would like to donate to my PDP-11 EDU project?

    >
    > While Pat almost certainly wouldn't give them away for free,
    > RELCOMSER seems to still have a large stock of RA71 and/or
    > RA72 drives for sale cheap. I picked up a couple when I
    > drove through IL a couple of years ago. Note that RA7x
    > seems to have a different interface than RA8x.


    No, the RA7x drives have just the same interface as any other RA drive.
    The only "problem" with RA7x drives is that you must have them in a box
    with a front panel in order to select the unit number. The only one
    having a unit number selection on the drive is the RA70.
    Without this, the drive will default to unit 0. So a maximum of one RA7x
    drive unless you have them in a box which I cannot remember the name of
    right now. That box is the same size as an RA9x drive, but fits four RA7x
    drives.

    Johnny

    Johnny Billquist || "I'm on a bus
    || on a psychedelic trip
    email: bqt@update.uu.se || Reading murder books
    pdp is alive! || tryin' to stay hip" - B. Idol
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  2. Re: ra disks

    Johnny Billquist wrote:
    > No, the RA7x drives have just the same interface as any other RA drive.


    Really? Mine seem to have DSSI instead of the SI connector.

  3. Re: ra disks

    Douglas A. Gwyn wrote:
    > Johnny Billquist wrote:
    >
    >> No, the RA7x drives have just the same interface as any other RA drive.

    >
    >
    > Really? Mine seem to have DSSI instead of the SI connector.


    Those aren't RA7x's. They are RF7x's.


    --
    John Santos
    Evans Griffiths & Hart, Inc.
    781-861-0670 ext 539

  4. Re: ra disks

    John Santos wrote:
    > Those aren't RA7x's. They are RF7x's.


    Ah, right are you.
    What RELCOMSER has are RF7x, not RA7x;
    sorry for the confusion I am.

  5. Re: ra disks

    In article , DAGwyn@null.net says...
    > John Santos wrote:
    > > Those aren't RA7x's. They are RF7x's.

    >
    > Ah, right are you.
    > What RELCOMSER has are RF7x, not RA7x;
    > sorry for the confusion I am.
    >


    I think they are very similar internally, and for all I know one
    can be converted to the other by swapping a personality module
    or cutting a jumper (maybe, wishful thinking?)

    If that's the case and someone knows how to do this, and there
    is a great surplus of one type or the other, that would be
    very useful information. (Possibly electronics could be
    salvaged from a mechanically dead RF7x to convert an RA7y to
    an RF7y or vice versa?)

    I have an RA72 that makes a loud racket and won't pass a read/write
    test... My guess is the bearings are gone and it won't track properly
    or fails to maintain constant speed (mechanical), so maybe someone
    could salvage the electronics to try to make an RF disk into an RA disk?
    Any takers? (I'm near Boston if any one wants to try their hand
    at brain surgery...)

    Or maybe both kinds are common enough not to be worth the trouble.

    The hard part for me was finding an SA7x box to hold the RA72's.


    --
    John

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