Image Map Image Map
Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 40

Thread: Tool For Floppy Drive

  1. #21
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    27,006
    Blog Entries
    20

    Default

    There are the so-called "digital alignment" disks made by Dysan and others back in the day. Basically, it involves sectors (or at least ID headers) with various displacements. When you're centered on track, basically you can read the same number of offset IDs in either direction. A similar scheme is used to check azimuth, although generally, there's not much one can do about it.

    I remember working with early Micropolis 5.25" drives. Micropolis was very proud of their multistep-per-track precision-ground leadscrew. And generally, those drives held radial alignment quite well, particularly when compared with garbage like the Shugart SA400 series (cam and follower arrangement). Regardless, we ended up sending a lot of drives back when we checked azimuth. Eventually, they got their act straightened out.

  2. #22

    Default

    Quote Originally Posted by Chuck(G) View Post
    Let me see if I understand:

    DS2D floppy formatted as 720K reads as 720K
    DSHD floppy formatted as 720K does not read as 720K (unless the density aperture has been covered)
    DS2D floppy formatted as 1.44M does not read (there is no HD hole).

    Some early machines did not use "media sense" drives; that is, drives that use the density aperture in the floppy to determine mode, but rather use what the host controller says the density is (like 5.25" media). Most notorious for this were some IBM PS/2 models.

    Have I summarized correctly?
    It was corrected and I put on the floppy tape to close the right side.

    Quote Originally Posted by Malc View Post
    Yup it seems that has been done though, Post #9

    @aesis What XT's do you have, IBM 5160 or Clones
    Maybe I had an IBM-XT..., no I have 2 XT:

    Philips NMS TC100
    Philips PCD100

    But what has the problem with the Panasonic JU-253-073P is the Philips NMS TC100.

    Quote Originally Posted by MicrocomputerSolutions View Post
    You can't just swap parts in any floppy drive without aligning it afterwards. Floppy drives do not automatically center heads over the written tracks like some/most hard drives.

    After swapping heads from one floppy drive to another, you must adjust the head alignment, and the index pulse timing. Otherwise, while you may be able to format, write and read a disk on that drive, another drive may not be able to use that disks and a disk that is written on another drive may get corrupted if you try writing on it with your repaired drive.

    As floppy drives moved from 8" to 5.25" to 3.5" the manufacturers stopped building the drives so they could easily be serviced. Modern 3.5" drives don;t have test points to connect test equipment for alignment/servicing purposes like the 8" drive had. On the other hand, modern 3.5" and smaller floppy drives are much less expensive than the 8" floppy drive were, even though they are less reliable than the old 8" floppy drives.
    Quote Originally Posted by Chuck(G) View Post
    There are the so-called "digital alignment" disks made by Dysan and others back in the day. Basically, it involves sectors (or at least ID headers) with various displacements. When you're centered on track, basically you can read the same number of offset IDs in either direction. A similar scheme is used to check azimuth, although generally, there's not much one can do about it.

    I remember working with early Micropolis 5.25" drives. Micropolis was very proud of their multistep-per-track precision-ground leadscrew. And generally, those drives held radial alignment quite well, particularly when compared with garbage like the Shugart SA400 series (cam and follower arrangement). Regardless, we ended up sending a lot of drives back when we checked azimuth. Eventually, they got their act straightened out.
    So if I understand correctly the heads read and can format but may not be aligned well?
    I understood correctly MicrocomputerSolutions ??
    If so, how do I perfectly align the floppy heads?

    I wanted a software just to adjust the radial position with the lower head, then later the upper head.

  3. #23
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    27,006
    Blog Entries
    20

    Default

    If a drive is misaligned, you can always format and read on the same drive because formatting lays down the basic "pathway" for data.

    The purpose of aligning a drive is to be able to exchange disks between drives by bringing the drive into conformance with a standard alignment.

  4. #24
    Join Date
    Aug 2006
    Location
    Chicagoland, Illinois, USA
    Posts
    5,015
    Blog Entries
    1

    Default

    So, what is a good procedure to follow for someone who has several drives that all appear to work, one drive that works only marginally, and only has access to blank floppies and commercially-duplicated software?
    Offering a bounty for:
    - A working Sanyo MBC-775
    - Documentation and original disks for: Panasonic Sr. Partner, Zenith Z-160 series
    - Music Construction Set, IBM Music Feature edition (has red sticker on front stating IBM Music Feature)
    - Any very old/ugly IBM joystick (such as the Franklin JS-123)

  5. #25
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    27,006
    Blog Entries
    20

    Default

    Depends what your criteria for "good enough" alignment are.

    You can use the commercial software floppies as an ersatz calibration standard, but I wouldn't try to publish any disks created with those drives. If you're going to give other people disks that you write, you want to adhere to a tighter standard, say +/- 1 mil or better on a 48 tpi drive.

    Since what I do primarily is read floppies and not write them, I've got a couple of drives that I tweak the alignment on, just to get a good read. I'd never distribute anything written with those.

  6. #26

    Default

    Unfortunately I also thought that I would leave as it was but...
    I formatted a floppy with the panasonic JU-253 from HD to DD and completed 100% formatting,OK!
    I'm going to insert the floppy on a modern PC with USB floppy drive,he sees it very well despite being formatted with the Panasonic,I extract the folder AVSCAN with all its files on the floppy,work properly!
    I take the floppy with the AVSCAN program in the I insert it on the XT and I do DIR,quickly see all the files and I say... "Perfect everything went smoothly"
    Start AVSCAN.EXE and after a few seconds I feel the head of the Floppy Drive that always sounds the same way that is the classic sound of the up and down,after a few seconds here is the usual message:

    error in reading the unit,general error impossible to continue,cancel,retry,returns.

    So conclusion of the result is that I can format with this panasonic but I can not read files extracted from other units.

    I'm desperate and I'm sure the reader is half-buried!

  7. #27
    Join Date
    Aug 2006
    Location
    Chicagoland, Illinois, USA
    Posts
    5,015
    Blog Entries
    1

    Default

    Quote Originally Posted by Chuck(G) View Post
    If you're going to give other people disks that you write, you want to adhere to a tighter standard, say +/- 1 mil or better on a 48 tpi drive.
    Is a commercial alignment disk is the only way to achieve this?

    (I actually am going to be giving people disks that I write next year as part of a project)
    Offering a bounty for:
    - A working Sanyo MBC-775
    - Documentation and original disks for: Panasonic Sr. Partner, Zenith Z-160 series
    - Music Construction Set, IBM Music Feature edition (has red sticker on front stating IBM Music Feature)
    - Any very old/ugly IBM joystick (such as the Franklin JS-123)

  8. #28
    Join Date
    Jan 2007
    Location
    Pacific Northwest, USA
    Posts
    27,006
    Blog Entries
    20

    Default

    DIR only reads the directory of the drive, not the files.

    On your XT you may want to verify the readability of the files with the command:

    COPY /B A:*.* NUL

    Which will read all files in a directory (but not those in a subdirectory) and drop the data in the bit-bucket.

  9. #29

    Default

    IT IS NOT FAULTY... IT IS NOT FAULTY!!! :urlo:

    I could read floppy new MF2HD formatted to DD!!!! : D
    The problem was to set the radial point track:0 with the head unit rotating the motor.., by virtue of trying I managed to get over the problem.
    Then I scanned with AVSCAN and found in addition to the Jerusalem virus (5/6 infected files) all the operating system with the Dark Avenger virus (out of the 50 infected files).
    I had to format!!!

    Anyway thanks to everyone for the interest,Thanksss!!!

  10. #30
    Join Date
    May 2006
    Location
    Hamilton, Ontario, Canada
    Posts
    3,680

    Default

    Quote Originally Posted by Chuck(G) View Post

    Mike:

    It depends on the drive and the application. Some systems require the "Drive Ready" signal, which not all HD have available, usually substituting the "DIsk Changed" signal on pin 34. However, some HD drives are very configurable, such as the Samsung SFD-321B. I've routinely modified those for 1.6MB operation with Ready on pin 34 and disk changed on pin 2 (some Japanese-made gear requires this).
    Chuck,

    Can this drive be hard-wired to work as a 720K drive or does it depend on what "class" of machine it's being used in?

    Does it require a driver like some of the 3 mode drives I've seen?

    Thanks.
    Legacy Computers and Parts

    Sales of, parts for, and repairs to, Vintage and Legacy computers.

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
  •