8 inch floppy drives interchangeable? - DEC

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  1. 8 inch floppy drives interchangeable?

    Hello everyone,

    I'm in the process of buying a legendary piece of (musical) hardware,
    which uses minicomputer age 8 inch floppy drives The system reportedly
    works, the only issue is its floppy drive, which needs to be fixed or
    replaced.

    Does anyone know if 8 inch floppy drives are interchangeable the same
    way as newer 3.5 inch ones are? Can I just get any other 8 inch floppy
    drive off eBay for $40-$50, plug it in and see things work? Or would
    it have to be the exact same rare model.

    Thank you in advance for all the help

    Keoki

  2. Re: 8 inch floppy drives interchangeable?

    [Please do not mail me a copy of your followup]

    Keoki spake the secret code
    thusly:

    >Does anyone know if 8 inch floppy drives are interchangeable the same
    >way as newer 3.5 inch ones are? Can I just get any other 8 inch floppy
    >drive off eBay for $40-$50, plug it in and see things work? Or would
    >it have to be the exact same rare model.


    I'm not an expert but my understanding is that some drives are
    interchangeable, but not all drives are interchangeable. You'll have
    to find a drive that is compatible with the one you have. How easy
    that is to do is impossible to say without knowing the drive.
    --
    "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download


    Legalize Adulthood!

  3. Re: 8 inch floppy drives interchangeable?

    On Jun 29, 6:27 pm, Keoki wrote:
    > Hello everyone,
    >
    > I'm in the process of buying a legendary piece of (musical) hardware,
    > which uses minicomputer age 8 inch floppy drives The system reportedly
    > works, the only issue is its floppy drive, which needs to be fixed or
    > replaced.
    >
    > Does anyone know if 8 inch floppy drives are interchangeable the same
    > way as newer 3.5 inch ones are? Can I just get any other 8 inch floppy
    > drive off eBay for $40-$50, plug it in and see things work? Or would
    > it have to be the exact same rare model.
    >
    > Thank you in advance for all the help
    >
    > Keoki


    What Richard said - it's potentially a lot more complex than today's
    3.5" floppies.

    8inch floppies were available in various densities (eg single and
    double), and sidedness (single or double), and interoperability of
    drives and media was not guaranteed. There's also the small matter of
    soft sectoring (sector timing is derived from timing info recorded on
    the media when it was formatted) vs hard sectoring (sector timing is
    derived from holes punched in the media in the factory).

    Assuming you aren't the only person in the world with one of these
    legendary but as yet unnamed boxes, are the other owners willing to
    share experiences eg wrt drives and media ? If not, are you confident
    that your machine will arrive with an appropriate but broken drive
    (rather than an inappropriate one added in eg a botched repair
    attempt)? If you have the real thing, there should be enough info to
    start looking for compatible replacements.

    Is http://www.torlus.com/floppy/forum/v...fb425e8feb6948
    relevant?

    Regards
    John

  4. Re: 8 inch floppy drives interchangeable?

    > Ishttp://www.torlus.com/floppy/forum/viewtopic.php?p=413&sid=c47c7ac232...
    > relevant?


    Hello John,
    You were close... the page is about a Fairlight, while the machine I'm
    concerned with is a Synclavier.

  5. Re: 8 inch floppy drives interchangeable?

    In article
    <12978d8a-5ec2-42a0-ac25-ce11cdd0ad31@w5g2000prd.googlegroups.com>,
    Keoki writes:

    > > Ishttp://www.torlus.com/floppy/forum/viewtopic.php?p=413&sid=c47c7ac232...
    > > relevant?

    >
    > Hello John,
    > You were close... the page is about a Fairlight, while the machine I'm
    > concerned with is a Synclavier.


    Aaahh yes, the Synclavier. I have a brochure and demonstration record
    (vinyl). My impression is that while the technology is probably dated
    by now, i.e. one could probably implement the whole thing on a PC now,
    musically it is still state-of-the-art. Correct?

    What did one cost new? $100,000?


  6. Re: 8 inch floppy drives interchangeable?

    On Jul 5, 7:31*am, hel...@astro.multiCLOTHESvax.de (Phillip Helbig---
    remove CLOTHES to reply) wrote:

    > Aaahh yes, the Synclavier. *I have a brochure and demonstration record
    > (vinyl). *My impression is that while the technology is probably dated
    > by now, i.e. one could probably implement the whole thing on a PC now,
    > musically it is still state-of-the-art. *Correct?


    Hello Phillip,

    I don't know, I'm hoping to find out by fixing up a unit :-) There is
    a discussion going on another thread whether the Timbre Frame
    Resynthesis the Synclavier offers (a type of wavetable synthesis) is
    related to the Korg Wavestation's wave sequencing. So far we did not
    find any poster who had enough experience with both to offer an
    educated answer.

    It's like the trivia I read in the papers the other day. Turns out,
    the closest living relative to the mighty, terrifying dinosaurs is the
    home chicken. Now here is a relation neither of the two would be in a
    hurry to advertise! In the same vein, for all we know, the
    Synclavier's Timbre Frame Resynthesis function could be the closest
    relative (the grandpa?) of the Korg Wavestation's wave sequencing. I
    don't know if it is or not. But if it is, I can see why neither the
    Synclavier, nor the Korg coders would be in a hurry to advertise
    it. :-)

  7. Re: 8 inch floppy drives interchangeable?

    >> Aaahh yes, the Synclavier

    googling around found
    http://www.500sound.com/workshop/syn...r_restore.html

    Unless you already have floppy disks for it
    or intend to use pre-recorded floppy disks,
    it may be in your interest to use a newer device.
    I think that web site notes their retrofit to newer drives.

    Most of the 8" drives I've handled (full or half height,
    single or double sided) use a rather standard 50 pin interface
    that's ALMOST identical to today's floppy interface.
    Tracing out the disk select lines seems to be a sure way
    to clarify the interface (it's possible some were sasi or scsi).

    -- Jeffrey Jonas
    jeffj@panix(dot)com
    The original Dr. JCL and Mr .hide

  8. Re: 8 inch floppy drives interchangeable?

    Jeff Jonas wrote:
    (snip)

    > Unless you already have floppy disks for it
    > or intend to use pre-recorded floppy disks,
    > it may be in your interest to use a newer device.
    > I think that web site notes their retrofit to newer drives.


    > Most of the 8" drives I've handled (full or half height,
    > single or double sided) use a rather standard 50 pin interface
    > that's ALMOST identical to today's floppy interface.


    The 50 pin interface is pretty usual for 8 inch drives.
    The power supplies are less standard. Many use 115VAC for
    the drive motor, and 24VDC for the stepper motor. Later
    drives used the 24VDC for the drive motor, also.

    > Tracing out the disk select lines seems to be a sure way
    > to clarify the interface (it's possible some were sasi or scsi).


    It is fairly easy to interface to 5.25in HD drives, which are
    pretty much a scaled down version of the 8 inch drive.
    (80 tracks instead of 77, but the data rate and rotation
    rate are the same.) For 3.5in HD the rotation rate was
    reduced from 360RPM to 300RPM. Most can probably survive
    that, with a large gap at the end of each track. Some may
    time out as the index pulse arrives later than expected.

    If you actually want to use the device, I would recommend
    going to 5.25in HD or 3.5in HD, the latter disks are still
    readily available. If you have existing 8in floppies, copy
    the data over when you do get an 8in drive.

    8in double side drives should be backward compatible
    with single side systems.

    -- glen


  9. Re: 8 inch floppy drives interchangeable?

    On Jul 19, 7:00*am, glen herrmannsfeldt wrote:

    > If you actually want to use the device, I would recommend
    > going to 5.25in


    Sounds good, but does anyone know which third party 5.25 floppy drive
    is compatible, format and connector-wise with the "original" N.E.D.
    Synclavier floppy drive?

  10. Re: 8 inch floppy drives interchangeable?

    Keoki wrote:
    > On Jul 19, 7:00 am, glen herrmannsfeldt wrote:


    >>If you actually want to use the device, I would recommend
    >>going to 5.25in


    > Sounds good, but does anyone know which third party 5.25 floppy drive
    > is compatible, format and connector-wise with the "original" N.E.D.
    > Synclavier floppy drive?


    It isn't hard to make a cable that will connect the appropriate
    pins on the usual 50 pin cable for an 8 inch floppy to the pins
    on a 34 pin cable for the 5.25 inch floppy.

    There is probably someone in this group that would make such
    a cable and sell it to you for a reasonable price. If not,
    try comp.os.cpm.

    If it isn't the popular 50 pin cable pinout then you
    are probably stuck.

    -- glen


  11. Re: 8 inch floppy drives interchangeable?

    On Sep 5, 6:33*am, glen herrmannsfeldt wrote:
    > Keoki wrote:
    > > On Jul 19, 7:00 am, glen herrmannsfeldt wrote:
    > >>If you actually want to use the device, I would recommend
    > >>going to 5.25in

    > > Sounds good, but does anyone know which third party 5.25 floppy drive
    > > is compatible, format and connector-wise with the "original" N.E.D.
    > > Synclavier floppy drive?

    >
    > It isn't hard to make a cable that will connect the appropriate
    > pins on the usual 50 pin cable for an 8 inch floppy to the pins
    > on a 34 pin cable for the 5.25 inch floppy.


    Format-wise, are all double density (DD) 5.25 floppy drives the same,
    or are there possible incompatibilities when reading a Synclavier
    double density OS floppy on a third party 5.25 DD floppy drive ?

  12. Re: 8 inch floppy drives interchangeable?

    On 2008-09-09, Keoki wrote:
    > Format-wise, are all double density (DD) 5.25 floppy drives the same,
    > or are there possible incompatibilities when reading a Synclavier
    > double density OS floppy on a third party 5.25 DD floppy drive ?


    No, but since we're talking about 8" here, you'd be looking for an HD
    5.25" drive rather than a DD drive.

    Since I'm reading this on comp.sys.dec, I probably ought to point out
    that there's a big difference between the way DEC did HD (RX31) and the
    way IBM did it. A DEC drive will change speeds; at high density, it runs
    at 360 RPM and it runs at 300 RPM at low density. An IBM-compatible drive
    doesn't change speeds; it always runs at 360 RPM. This is why PCs have
    to have three data rates: 500KHz (HD disk in HD drive), 300KHz (DD disk
    in HD drive), and 250KHz (DD disk in DD drive).

    3.5" drives always run at 300 RPM, which is why a high-density 3.5"
    floppy has 1.44MB instead of the 1.2MB of the 5.25" drives.
    --
    roger ivie
    rivie@ridgenet.net

  13. Re: 8 inch floppy drives interchangeable?

    In article <6b8214b1-ad7f-4196-b4bd-8cf29df549ef@r15g2000prd.googlegroups.com>,
    Keoki writes:
    > On Sep 5, 6:33*am, glen herrmannsfeldt wrote:
    >> Keoki wrote:
    >> > On Jul 19, 7:00 am, glen herrmannsfeldt wrote:
    >> >>If you actually want to use the device, I would recommend
    >> >>going to 5.25in
    >> > Sounds good, but does anyone know which third party 5.25 floppy drive
    >> > is compatible, format and connector-wise with the "original" N.E.D.
    >> > Synclavier floppy drive?

    >>
    >> It isn't hard to make a cable that will connect the appropriate
    >> pins on the usual 50 pin cable for an 8 inch floppy to the pins
    >> on a 34 pin cable for the 5.25 inch floppy.

    > Format-wise, are all double density (DD) 5.25 floppy drives the same,
    > or are there possible incompatibilities when reading a Synclavier
    > double density OS floppy on a third party 5.25 DD floppy drive ?


    I have seen numerous formats that were unreadable even at the sector level
    on common 8" systems. Immediate examples that come to mind as Tektronix
    Terminals (which could do CPM format but also had their oen format), Univac
    UTS-100 and some of the older Word Processors, like Xerox. I am sure there
    were many other incompatable formats as well. I have been called upon on
    a number of occaisions to read (or try to read) old 8" disks as I still
    have a number of different systems with working 8" floppies. It can be
    an adventure!! :-)

    bill

    --
    Bill Gunshannon | de-moc-ra-cy (di mok' ra see) n. Three wolves
    billg999@cs.scranton.edu | and a sheep voting on what's for dinner.
    University of Scranton |
    Scranton, Pennsylvania | #include

  14. Re: 8 inch floppy drives interchangeable?

    On Sep 8, 4:56 pm, Roger Ivie wrote:
    > On 2008-09-09, Keoki wrote:
    >
    > > Format-wise, are all double density (DD) 5.25 floppydrivesthe same,
    > > or are there possible incompatibilities when reading a Synclavier
    > > double density OS floppy on a third party 5.25 DD floppy drive ?

    >
    > No, but since we're talking about8" here, you'd be looking for an HD
    > 5.25" drive rather than a DD drive.


    The seller of the Synclavier system emailed he has a 5.25 DD operating
    system floppy as well, so I *was* talking about reading a genuine 5.25
    DD Synclavier floppy on a third party 5.25 drive. (A slight change of
    topic, I guess :-)

    He might have identified a 5.25 HD floppy wrongly as a 5.25 DD, but a
    good third party 5.25 HD floppy drive will probably handle both HD and
    DD formats, I presume. (I might be wrong.) The main gist of my last
    question was if anyone knows whether it's possible to read a 5.25 DD
    Synclavier floppy in a generic 5.25 drive, or do Synclavier floppies
    use some peculiar sector size, allocation table, or whatever else that
    prevents this.

    Although Synclavier did built a lot of custom sound generating
    hardware, I doubt they went into the costly floppy drive building
    business too just for the sake of it; they probably used some third
    party FD mechanism and relabeled it. Anyone knows?

  15. Re: 8 inch floppy drives interchangeable?

    Keoki wrote:

    > On Sep 8, 4:56 pm, Roger Ivie wrote:


    >>On 2008-09-09, Keoki wrote:


    >>>Format-wise, are all double density (DD) 5.25 floppydrivesthe same,
    >>>or are there possible incompatibilities when reading a Synclavier
    >>>double density OS floppy on a third party 5.25 DD floppy drive ?


    Format wise, all you need to know for the drive is DD or HD.
    (SD will work in DD drive.) The drive converts the disk data
    to a digital signal independent of the format. The controller
    will have to understand the sector length and format, and there
    are a few choices for those. Most systems use one of the
    original IBM standards. Apple until they started using HD
    disks had all their own formats. DEC used the IBM format
    for single density, but their own special format for double
    density.

    >>No, but since we're talking about8" here, you'd be looking for an HD
    >>5.25" drive rather than a DD drive.


    > The seller of the Synclavier system emailed he has a 5.25 DD operating
    > system floppy as well, so I *was* talking about reading a genuine 5.25
    > DD Synclavier floppy on a third party 5.25 drive. (A slight change of
    > topic, I guess :-)


    The usual PC floppy controller will read a variety of sector
    lengths, but not all software (OS) know how to do that.
    That is, for making a bitwise (actually blockwise) copy
    of a disk. Unix/Linux can usually do it.

    > He might have identified a 5.25 HD floppy wrongly as a 5.25 DD, but a
    > good third party 5.25 HD floppy drive will probably handle both HD and
    > DD formats, I presume. (I might be wrong.) The main gist of my last
    > question was if anyone knows whether it's possible to read a 5.25 DD
    > Synclavier floppy in a generic 5.25 drive, or do Synclavier floppies
    > use some peculiar sector size, allocation table, or whatever else that
    > prevents this.


    I don't know this one at all.

    > Although Synclavier did built a lot of custom sound generating
    > hardware, I doubt they went into the costly floppy drive building
    > business too just for the sake of it; they probably used some third
    > party FD mechanism and relabeled it. Anyone knows?


    -- glen


  16. Re: 8 inch floppy drives interchangeable?

    Keoki wrote:

    > The seller of the Synclavier system emailed he has a 5.25 DD operating
    > system floppy as well, so I *was* talking about reading a genuine 5.25
    > DD Synclavier floppy on a third party 5.25 drive. (A slight change of
    > topic, I guess :-)


    http://www.mixfoundation.org/hof/04techof.html

    seems to indicate 5.25in drive. That would have been
    before HD, maybe even before DD.

    -- glen


  17. Re: 8 inch floppy drives interchangeable?

    A hindsight note to those who might end up in a similar situation:
    don't mess with a Synclavier. (Unless you don't care for it.)

    I bought a well preserved 5.25 replacement FD mechanism that came from
    an other Synclavier. Once we peeked into our Synclav floppy drive, we
    discovered that even to swap this *genuine* mechanism isn't a plug and
    play affair. A Synclavier tech will still have to redo some of the
    electrical wiring for the slightly different replacement mechanism to
    work with the enclosure and its red load button.

    I was warned already that inside a Synclavier every single card,
    memory chip and other doohickey is a world to itself, and often
    incompatible with the same card or chip or doohickey in another
    Synclavier of same year and model. Got that. But that even frigging FD
    mechanisms differ from each other and require rewiring of the FD
    enclosure... now who would have expected this. Apparently this is the
    case.

    So a word to the wise, if you think you can easily replace *any* part
    in a Synclavier yourself, you are about to get more experience :-)
    (And/or a big bill, like the one I'm about to get hit with)

    Thank you all for your suggestions, though
    Keoki

    On Sep 16, 5:04*pm, glen herrmannsfeldt
    wrote:
    > Keoki wrote:
    > > The seller of the Synclavier system emailed he has a 5.25 DD operating
    > > system floppy as well, so I *was* talking about reading a genuine 5.25
    > > DD Synclavier floppy on a third party 5.25 drive. (A slight change of
    > > topic, I guess :-)

    >
    > http://www.mixfoundation.org/hof/04techof.html
    >
    > seems to indicate 5.25in drive. *That would have been
    > before HD, maybe even before DD.
    >
    > -- glen



  18. Re: 8 inch floppy drives interchangeable?

    Keoki wrote:
    > A hindsight note to those who might end up in a similar situation:
    > don't mess with a Synclavier. (Unless you don't care for it.)


    > I bought a well preserved 5.25 replacement FD mechanism that came from
    > an other Synclavier. Once we peeked into our Synclav floppy drive, we
    > discovered that even to swap this *genuine* mechanism isn't a plug and
    > play affair. A Synclavier tech will still have to redo some of the
    > electrical wiring for the slightly different replacement mechanism to
    > work with the enclosure and its red load button.

    (snip)

    > So a word to the wise, if you think you can easily replace *any* part
    > in a Synclavier yourself, you are about to get more experience :-)
    > (And/or a big bill, like the one I'm about to get hit with)


    I would only recommend someone with some electronics experience
    work on most electronic systems.
    (snip)

    >>Keoki wrote:


    >>>The seller of the Synclavier system emailed he has a 5.25 DD operating
    >>>system floppy as well, so I *was* talking about reading a genuine 5.25
    >>>DD Synclavier floppy on a third party 5.25 drive. (A slight change of
    >>>topic, I guess :-)


    I don't know about that one. I was suggesting a possible replacement
    for the 8in drive that would use the same format on an HD 5.25in drive.
    That may or may not be related to the official one. Even better
    (easier to find) 3.5in HD.

    -- glen


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