Image Map Image Map
Page 1 of 2 12 LastLast
Results 1 to 10 of 14

Thread: Odd floppy drive / single dentisty drives and diskettes

  1. #1

    Default Odd floppy drive / single dentisty drives and diskettes

    I bought this floppy drive long time ago and I tought it was regular one mounted in IBM's computers. I think I was asking about this drive some time ago but noone replied.



    It's manufactured by Siemens, there's date - 10-1982. I've connected it to PC computer and tried to write some data on DD disc formatted as 160KB (the drive has one read/write head) sometimes I could save and read the data but only few times. I'm pretty sure it isn't PC drive, it has vired height (about 3/4 of full height one). I guess it can be single density drive.

    Are such drives and diskettes common?
    And what systems used single density?

    Luke

  2. #2

    Default

    Quote Originally Posted by Luke View Post
    It's manufactured by Siemens, there's date - 10-1982. I've connected it to PC computer and tried to write some data on DD disc formatted as 160KB (the drive has one read/write head) sometimes I could save and read the data but only few times. I'm pretty sure it isn't PC drive, it has vired height (about 3/4 of full height one). I guess it can be single density drive.
    This appears to be a Siemens FDD-100. A variant of these drives was used in the Osbornes (though not this particular model).

    Quote Originally Posted by Luke View Post
    Are such drives and diskettes common?
    And what systems used single density?
    Single-density refers to disk formats that store less than 100k of data. No PC ever used them, although PC floppy controllers are supposed to support SD. Because it was not a standard format, many controllers did not implement SD support. That's probably why it doesn't work correctly in your machine.

    A number of systems used SD drives, including the Osborne and various other CP/M boxes. The TRS-80 Model I also used them, as well as the Atari 810 drives.

  3. #3
    Join Date
    Apr 2003
    Location
    Saginaw, MI, USA 48601
    Posts
    8,763
    Blog Entries
    9

    Default

    The only machine that pops into my head is the Morrow MD-x CP/M boxes, which used those 3/4 high drives. I have a HH drive here with 3/4 high faceplate that came out of a Burroughs external enclosure, but it's DSDD.

    --T
    Teach your children how to think, not what, and hold 'em close, not tight.
    _____________________________________________

    Please visit the Vintage-Computer Wiki. Contributers welcome.

  4. #4
    Join Date
    Apr 2005
    Location
    Stevens Point, Wisconsin
    Posts
    2,315

    Default Fdd-100

    Doesn't single density typically refer to FM recording and double density to MFM ?

    The FDD-100's were actually capable of either FM,MFM, IBM System 3740, IBM System 32 formats, depending on what options the were shipped with, and of course the controller.

    The drive looks more like a 100-8 than a 100-5 (at least to me) the -5 don't have that big 40-pin pseudo-pal sitting on it.
    Here's a link to the 100-5 manual with pictures.
    http://www.pestingers.net/PDFs/Disk_...100-5_vol1.pdf
    patscc

  5. #5

    Default

    Quote Originally Posted by patscc View Post
    Doesn't single density typically refer to FM recording and double density to MFM ?
    Yes, as I understand it the density is not so much related to the drive, but rather the disk controller. I have an old Tandon single sided 40 track drive that writes single density in my System 80 and double density in the Kaypro. It's a matter of what it's attached to.

    Tez
    ------------------------------------------------
    My vintage collection: https://classic-computers.org.nz/collection/
    My vintage activities blog: https://www.classic-computers.org.nz/blog/
    Twitter: @classiccomputNZ ; YouTube Videos: (click here)


  6. #6
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    30,680
    Blog Entries
    20

    Default

    Quote Originally Posted by tezza View Post
    Yes, as I understand it the density is not so much related to the drive, but rather the disk controller. I have an old Tandon single sided 40 track drive that writes single density in my System 80 and double density in the Kaypro. It's a matter of what it's attached to.
    Exactly. (Legacy) floppy drives (and for that matter "MFM"/ST506/ST412 interface hard drives) are brain-dead. They record what you tell them to, be it FM, MFM, MMFM, GCR, or anything else. Basically, heads write drivers/read amp circuitry, positioner and a spindle motor.

    You could probaby record PPM audio on a floppy if the itch struck you.

    There are some 8" drives with built-in FM data separators, but those are always optional in their application.

  7. #7

    Default

    Quote Originally Posted by Luke View Post
    And what systems used single density?
    The TRS-80 Model 1 originally did. Many people upgraded to double-density and a more reliable data separation though.

    I think the Osborne 1s were originally single density too. (but don't quote me on that).

    Tez
    ------------------------------------------------
    My vintage collection: https://classic-computers.org.nz/collection/
    My vintage activities blog: https://www.classic-computers.org.nz/blog/
    Twitter: @classiccomputNZ ; YouTube Videos: (click here)


  8. #8
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    30,680
    Blog Entries
    20

    Default

    What brand of 5.25" drives are these?

    Last edited by Chuck(G); February 1st, 2009 at 11:02 PM. Reason: Okay, no hotlinking to other folks' sites...

  9. #9

    Default

    That's major LOL time. The guy at that website doesn't want you hotlinking to his site. It's a funny warning, as in humorous.

    www.ex-astris-scientia.org

  10. #10
    Join Date
    Apr 2005
    Location
    Stevens Point, Wisconsin
    Posts
    2,315

    Default Sd

    The Osborne 1 did in fact ship with single-density drives.
    The original BBC micro comes to mind and the early Atari's had a SS/SD format.
    patscc

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •