- I just tried to make a disk with ImageDisk and I am getting errors.
- I just made this disk with ImageDisk, but it won't boot.

Q: Whats wrong?

A: Lots of things can go wrong (this is not an exact science).

ImageDisk is a very powerful and flexible tool, however this capability
comes at a price - you actually have to know a little bit about what
you are doing to make effective use of the tool. I've put the information
that you need to know in the ImageDisk documentation and help files, if
you really want to make disks that work, take the time to read it and
learn about the differences between floppy drives, data rates and the
compatibility issues involved. This is the best and most complete
answer to the above question.

I've been getting more and more mail from people who have obviously
"skipped" the documentation, tried to make disk which didn't work right
away, so the next step that comes to their mind is to contact me.
Please DO NOT ask me for help if you have not read the documentation!

Here are the most common problems that people encounter, and the
suggestions I have to offer:

- Drive type does not match that in which the image was recorded.
  Most commonly occuring with 5.25" drives.
  IMDA will suggest drive types and settings which might be suitable.

  Use IMDU to determine the data rate at which the image was recorded.

  If the disk was recorded at 250kbps and you are attempting to write
  with a HD (1.2M) drive, you MUST set the 250->300kbps data rate
  translation (also, see documentation regarding other compatibility
  problems).

  If the disk was recorded at 300kbps and you are attempting to write
  with a DD (360k) drive, you MUST set the 300->250kbps data rate
  translation.

  NOTE: I try to record images on the actual drive type that is used
  in a particular system - so 5.25" DD images are recorded on a 5.25"
  DD drive at 250kbps. Most PCs of AT or later vintage with a 5.15"
  drive will have a 1.2M HD (300kbps) type and data rate translation
  will have to be used to recreate those images.


- PC is not capable of writing single-density.
  Most PC floppy disk controllers are not capable of single-density
  operation. Single-density formats have never been officially used
  on the PC, and many manufacturers do not bother to include the
  hardware necessary to support single-density operation.

  Find another PC, or an add-in floppy card which does support
  single-density operation.


- Dirty heads / drive mechanics.
  You finally got a disk image for your wunder-system from the 70's,
  so you rooted around in your basement, and found an old DD drive
  from an XT stuffed in under the bottom shelf. After blowing the bugs
  and dust out of it, you connect it to your PC - and start making disks.
  - Funny, they don't seem to be working.

  Use good clean reliable drives - any drive thats been sitting for
  "years" is likely to have collected dust and corrosion. This includes
  the drives in your classic system! - Clean up the host drive(s) before
  you try and make disks, and the system drive before you try and boot.
  ImageDisk has plenty of features to help diagnose drive problems.


- Marginal disk format.
  The PC uses a fairly inflexible floppy disk controller chip, which
  cannot handle data as close to the index pulse as the controllers
  in some non-PC systems. These system may pack extra data onto the
  disk (for example, 10x512byte sectors resulting in 400k disks).

  Some PC controllers can handle this better than others.
  You may also be able to create the disk by slowing the drive
  down by 5-10rpm, allowing extra time for the data to be written
  before the next index pulse occurs. See the ImageDisk notes.


- Target system not working
  Drives go bad, corrosion gets into sockets and connectors, and
  the computer you are trying to boot may not be as reliable as
  you think.

  - Check to make sure the boot drive selects (light comes on) and
    the motor/diskette spins when you try and boot the system. With
    some drives, you may hear a click as the head loads. If this does
    not happen, it's likely that your system isn't even running it's
    boot program.

  - With the power-off and diskette removed, try manually positioning
    the drive head out to the inside position of it's travel. When you
    power the system on and attempt to boot, you should see the head
    retract to track-0 (on a few systems, it goes to the middle of
    it's travel). If it does not move, makes funny/unexpected noises,
    or appears to move erraticly, clean and lubricate the drive
    positioner.

  - If the above looks good, make sure you have the correct/proper
    boot disk. To verify that the image was written correctly by
    ImageDisk, try reading the newly written diskette into another
    image file - then use IMDU to compare them, no differences in
    the data area should be reported.

  - Check your console connection - if it's integrated video, do
    you have a blinking cursor on the screen. If it's a serial TTY
    do you have it connected to the right port, and is it connected
    properly. Use an RS-232 "light box" to confirm that RXD, TXD and
    any control signals used are being correctly driven. Is the
    terminal set to the right mode and baud rate.

    - Most operating systems occupy more than one track of the boot
      disk, so for MOST systems, when you boot, you will see the head
      step out to the boot track, then it will step in one, two or
      more tracks, usually pausing slightly on each one as it reads
      the data from that track. On some systems, it will then seek
      around the disk, reading system files, directory entries etc.
      If you are seeing disk activity after the initial seek to the
      boot track, this is a good sign that the system may be actually
      booting.

    - With the terminal disconnected, use a light-box, and note that
      only ONE of RXD or TXD should be lit. Reconnect the terminal
      and the other (RXD or TXD) should also light. Watch the light
      that was on when only the computer was connected to see if it
      flickers during the boot process - this indicates that messages
      are being sent to the terminal - check the terminal settings
      and connections to determine why you are not seeing them.

    - If you don't see RXD/TXD activity, try all the other ports
      on the system - perhaps the boot disk assigns the console to
      a different port than you expected.

