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floppy drive emulator — Parallax Forums

floppy drive emulator

ArchiverArchiver Posts: 46,084
edited 2003-12-03 22:29 in General Discussion
I am trying to find a way to emulate (in software or hardware, using
BS2 or PC or both) an old 8 inch floppy drive.

My reason is this, I have an old machine tool with an old
control ,that is not a PC, that has a floppy disk controller (I can
get more details) and this 8 inch drive attached to it, but the drive
is failing and I don't want to replace the drive unit.

What I want to do is remove the drive, keeping the controller card in
the machine) and connect "something" to the card that fakes out the
controller card into thinking it is reading and writing from the
dirve when it is really "interfacing" with a BS2 and/or PC.

I need to be able to read in the data that the old control is
writing, once I get the file, I don't have to be able to "give it
back" via the controller card, I can actually give it back via a
paper tape reader that is also on it (although writing back to teh
controller would be a plus).

I havn't yet been sucessful in finding any way to emulate this drive,
no one that I have spoken or typed to has given me any hope, they all
say it can't be done, but I think it is possible.

Any suggestions?

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-12-03 19:43
    Hmmmmm.....

    A very long time ago I actually built an interface board for an 8" floppy
    drive (for an Ohio Scientific Computer), so I remember some of the internal
    workings of the beast...

    You not only need to emulate the data stream for the operating system and
    driver, but the mechanicals of the drive as well. For instance, on
    initialization, the floppy drive seeks back its stepper motor until the zero
    track switch is made good. This tell the driver its ready to go. Then it
    seeks forward one pulse at a time, reading each track once the little hole
    in the media goes past another optical sensor. Then the floppy drive streams
    out one block/track worth of information to the interface. The controller
    steps forward one track, the drive waits for the hole to go past the sensor,
    and the next track streams out. Besides the initialization/track-0 feedback,
    you should be able to increment blocks of memory and feed them out to the
    controller. As I remember, this was basically TTL level logic. Figuring out
    your block sizes and such is the trick though, since in the early days every
    manufacturer did his own thing.

    What sort of Operating System is this thing using????

    Mike Sokol
    www.modernrecording.com
    mikes@m...


    " One should not increase, beyond what is necessary,
    the number of entities required to explain anything"...
    -William of Occam-


    Original Message
    From: "xutsim" <xutsim@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Wednesday, December 03, 2003 11:21 AM
    Subject: [noparse][[/noparse]basicstamps] floppy drive emulator


    > I am trying to find a way to emulate (in software or hardware, using
    > BS2 or PC or both) an old 8 inch floppy drive.
    >
    > My reason is this, I have an old machine tool with an old
    > control ,that is not a PC, that has a floppy disk controller (I can
    > get more details) and this 8 inch drive attached to it, but the drive
    > is failing and I don't want to replace the drive unit.
    >
    > What I want to do is remove the drive, keeping the controller card in
    > the machine) and connect "something" to the card that fakes out the
    > controller card into thinking it is reading and writing from the
    > dirve when it is really "interfacing" with a BS2 and/or PC.
    >
    > I need to be able to read in the data that the old control is
    > writing, once I get the file, I don't have to be able to "give it
    > back" via the controller card, I can actually give it back via a
    > paper tape reader that is also on it (although writing back to teh
    > controller would be a plus).
    >
    > I havn't yet been sucessful in finding any way to emulate this drive,
    > no one that I have spoken or typed to has given me any hope, they all
    > say it can't be done, but I think it is possible.
    >
    > Any suggestions?
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-12-03 22:29
    For more information, you might want to contact:
    http://pluto.njcc.com/~hjohnson/s_drives.html

    He may even have an 8" floppy drive to sell
    you -- certainly, he has LOTS of manuals.

    Also check: http://www.classiccmp.org/pipermail/cctech/2003-
    August/017711.html
    (reassemble link in notepad)

    --- In basicstamps@yahoogroups.com, "Mike Sokol" <mike.sokol@m...>
    wrote:
    > Hmmmmm.....
    >
    > A very long time ago I actually built an interface board for an 8"
    floppy
    > drive (for an Ohio Scientific Computer), so I remember some of the
    internal
    > workings of the beast...
    >
    > You not only need to emulate the data stream for the operating
    system and
    > driver, but the mechanicals of the drive as well. For instance, on
    > initialization, the floppy drive seeks back its stepper motor until
    the zero
    > track switch is made good. This tell the driver its ready to go.
    Then it
    > seeks forward one pulse at a time, reading each track once the
    little hole
    > in the media goes past another optical sensor. Then the floppy
    drive streams
    > out one block/track worth of information to the interface. The
    controller
    > steps forward one track, the drive waits for the hole to go past
    the sensor,
    > and the next track streams out. Besides the initialization/track-0
    feedback,
    > you should be able to increment blocks of memory and feed them out
    to the
    > controller. As I remember, this was basically TTL level logic.
    Figuring out
    > your block sizes and such is the trick though, since in the early
    days every
    > manufacturer did his own thing.
    >
    > What sort of Operating System is this thing using????
    >
    > Mike Sokol
    > www.modernrecording.com
    > mikes@m...
    >
    >
    > " One should not increase, beyond what is necessary,
    > the number of entities required to explain anything"...
    > -William of Occam-
    >
    >
    >
    Original Message
    > From: "xutsim" <xutsim@y...>
    > To: <basicstamps@yahoogroups.com>
    > Sent: Wednesday, December 03, 2003 11:21 AM
    > Subject: [noparse][[/noparse]basicstamps] floppy drive emulator
    >
    >
    > > I am trying to find a way to emulate (in software or hardware,
    using
    > > BS2 or PC or both) an old 8 inch floppy drive.
    > >
    > > My reason is this, I have an old machine tool with an old
    > > control ,that is not a PC, that has a floppy disk controller (I
    can
    > > get more details) and this 8 inch drive attached to it, but the
    drive
    > > is failing and I don't want to replace the drive unit.
    > >
    > > What I want to do is remove the drive, keeping the controller
    card in
    > > the machine) and connect "something" to the card that fakes out
    the
    > > controller card into thinking it is reading and writing from the
    > > dirve when it is really "interfacing" with a BS2 and/or PC.
    > >
    > > I need to be able to read in the data that the old control is
    > > writing, once I get the file, I don't have to be able to "give it
    > > back" via the controller card, I can actually give it back via a
    > > paper tape reader that is also on it (although writing back to teh
    > > controller would be a plus).
    > >
    > > I havn't yet been sucessful in finding any way to emulate this
    drive,
    > > no one that I have spoken or typed to has given me any hope, they
    all
    > > say it can't be done, but I think it is possible.
    > >
    > > Any suggestions?
    > >
    > >
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the
    Subject and
    > Body of the message will be ignored.
    > >
    > >
    > > Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
    > >
    > >
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