









                                   ImageDisk

                                       A
                                Diskette Imaging
                                    program
                                      for
                                  Soft-Sector
                                    Formats





                                  Version 1.11

                              Revised 16-Feb-2006










                       Copyright 2005-2006 Dave Dunfield
                              All rights reserved.



                                   ImageDisk

                               TABLE OF CONTENTS


                                                                         Page

     1. INTRODUCTION                                                        1

        1.1 License                                                         2
        1.2 System Requirements                                             3
        1.3 Command Line Options                                            4

     2. MAIN MENU COMMANDS                                                  5

        2.1 (S)ettings                                                      5
        2.2 (R)ead                                                          9
        2.3 (W)rite                                                         9
        2.4 (A)lign/test                                                    9
        2.5 (C)lean                                                        10
        2.6 (T)est RPM                                                     10
        2.7 Track e(X)clusion map                                          11
        2.8 (F)ormat                                                       11

     3. FLOPPY DRIVE TYPES                                                 12

        3.1 5.25" Double Density                                           12
        3.2 5.25" Quad Density                                             12
        3.3 5.25" High Density                                             13
        3.4 3.5" Double Density                                            13
        3.5 3.5" High Density                                              14
        3.6 8" Floppy Drive                                                14
        3.7 Writing 40 track disks on 80 track drives.                     14
        3.8 Easy/Cheap 8" drive adapter                                    15

     4. TIPS AND TRICKS                                                    18

        4.1 PC floppy controllers are DIFFERENT!                           18
        4.2 Slowing the drive                                              18
        4.3 Identifying an image                                           19
        4.4 Writing a 250kbps image on a HD drive                          19
        4.5 Writing a 300kbps image on a DD drive                          19
        4.6 Reading DD/QD images on HD drives                              19

     5. MISC. Topics                                                       20

        5.1 PC Diskette Drive Types                                        20
        5.2 DD Transfer Rate (250kbps <> 300kbps)                          20
        5.3 Double Stepping                                                20
        5.4 Gap Lengths                                                    21
        5.5 Differences from TeleDisk                                      21
        5.6 256 Tracks / 255 Sectors?                                      21
        5.7 Aligning a drive                                               22


    ImageDisk                                              Table of Contents

                                                                         Page
     6. IMAGE FILE FORMAT                                                  23

        6.1 Mode value                                                     23
        6.2 Sector size                                                    23
        6.3 Head value                                                     23
        6.4 Sector numbering map                                           24
        6.5 Sector Cylinder Map                                            24
        6.6 Sector Head map                                                24
        6.7 Sector Data Records                                            24

     7. IMDU: ImageDisk Utility                                            25

        7.1 Introduction                                                   25
        7.2 Command line options                                           25

     8. BIN2IMD: Binary to Image utility                                   27

        8.1 Introduction                                                   27
        8.2 Command line options                                           27
        8.3 Mixed format disks - Command option files                      29
    ImageDisk                                                        Page: 1


    1. INTRODUCTION

       ImageDisk is a program which reads entire diskette images into  files
       and can later recreate exact copies of the diskettes in order to:

        - Archive diskette images for long term storage.
        - Make it possible to transfer diskettes via the internet.

       Unlike DISKCOPY,  ImageDisk is not limited to PC format disks and  PC
       type diskette drives.  It has been designed to handle any drive  type
       and disk format possible with the PCs disk controller hardware.

       ImageDisk was created to address the problem of preserving system and
       application diskettes for classic computers.  Floppy disks are rarely
       used with modern PCs,  however they are the  "bread  and  butter"  of
       classic  systems.  Without  the  system/application  diskettes  these
       important artifacts of our digital history will become silent.

       ImageDisk was created by:

                Dunfield Development Services
                115 Manion Heights Cres.
                RR#2 Carp, Ontario Canada
                K0A 1L0

                tel: 613-256-5820               fax: 613-256-5821

                http://www.dunfield.com         <=  Visit my collection
                                                    of classic computers.
    ImageDisk                                                        Page: 2


       1.1 License

          This ImageDisk package is Copyright 2005-2006 Dave  Dunfield,  who
          grants the following free license for non-commercial use. You may:

          - Use the package for personal/hobby purposes for as long  as  you
            wish, on as many computers as you wish.

          -  Redistribute  copies  of  the  package  provided  none  of  the
            copyright  material  has  been  altered  or  omitted  from   the
            distributed version.  Additions to the package must  be  clearly
            marked as such.

          - Create/manipulate .IMD files with no restriction. The disk image
            file format specification  is  hereby  placed  into  the  public
            domain.

          All  rights  and  permissions  not  listed  above  are  explicitly
          reserved by the author.

          Use of this software is entirely at  your  own  risk.  The  author
          makes no guarantee of the suitability of  this  software  for  any
          particular purpose.

          Copyright law prohibits duplication of material so  protected.  It
          is your responsibility to determine the legality of any particular
          use of this software.  This package is NOT intended as a means  to
          bypass software copy protection.

          By using this software,  you accept all responsibility of any kind
          which may result from such use.  You agree to indemnify  and  hold
          harmless the author and his agents from any action which may arise
          from your use of the software.
    ImageDisk                                                        Page: 3


       1.2 System Requirements

          ImageDisk  requires  a  DOS  based  PC  with  an  AT  type  floppy
          controller.  Although ImageDisk will run on a 4.77Mhz  PC/XT  type
          machine,  some of the analysis functions are  real-time  intensive
          and best results will be obtained with  a  486  class  machine  or
          better.

          ImageDisk *MAY* run under versions of Windows which provide direct
          access to hardware  (Win9x),  however a pure  DOS  environment  is
          highly recommended. TSRs or other drivers which interfere with the
          real-time  operation  of  the  system  may  cause  problems   with
          ImageDisk.

          ImageDisk will NOT run  under  operating  systems  which  prohibit
          access  to  the  floppy  disk  controller   hardware,   such   as:
          WinNT/2000/Xp.

          1.2.1 Floppy Diskette Controller

             ImageDisk assumes that you have an AT  compatible  floppy  disk
             system.  Ie: one on which the data rate can be set.  If you use
             ImageDisk with a PC/XT type diskette controller,  you MUST  use
             the command line  option  LR=250  to  lock  the  data  rate  at
             250kbps.  If you do not,  then Image files will have  incorrect
             transfer rate values encoded within them.

             Without this option,  ImageDisk might  "try"  a  data  rate  of
             500kbps or 300kbps and find that  it  works  -  because  it  is
             actually is fixed at 250kbps in hardware,  and happily write an
             image file indicating the wrong value.

             NOTE:  A PC/XT controller will NOT be able to  read  HD  or  8"
             disks. It is NOT recommended to use ImageDisk with a PC/XT type
             floppy disk system.

             Also note: Many floppy controllers are limited designs which do
             not work well with non-PC formats. All PCs are NOT THE SAME!
    ImageDisk                                                        Page: 4


       1.3 Command Line Options

        Use: IMD [CMDfile] [options]

            /4                  - Assume 4 drives/FDC           [2] *
            /B                  - select drive B                [A]
            /C                  - select drive C                [A] *
            /D                  - select drive D                [A] *
            /F                  - perform Full analysis         [off]
            /H                  - inhibit initial Help screen   [enabled]
            /M                  - force Monochrome video        [color]
            /N                  - force Non-deleted data        [off]
            /S[addr]            - use Secondary FDC at [372]    [pimary/3F2]
            C=1-255             - set number of Cylinders       [80]
            CP=[1-9]            - number of Cleaning Passes     [3]
            D=path              - default read/write Directory  [current]
            DS=0-1              - Double-Step (0=OFF, 1=ON)     [Original]
            FF=00-FF            - Format Fill value             [E5]
            GF=0-255            - Format Gap                    [Calculated]
            GW=0-255            - Write Gap                     [Calculated]
            IL=[1-99]           - InterLeave (blank=BestGuess)  [As read]
            LR=250/300/500      - Lock data Rate                [off]
            P=1-3[,cyl[,wf,wr]] - enable Parallel-port          [Off]
            R=0-255             - select Retries                [5]
            S=1-2               - set number of Sides           [Original]
            SD=0-2000           - Delay after Step (ms)         [55]
            SR=1-16             - Step Rate (ms)                [8]
            HL=2-254            - Head Load time (ms)           [254]
            HU=16-240           - Head Unload time (ms)         [240]
            T5=250/300/500      - 500khz Translate              [500]
            T3=250/300/500      - 300khz Translate              [300]
            T2=250/300/500      - 250khz Translate              [250]
            X=track[,to_track]  - eXclude entire track(s)       [None]
            X0=track[,to_track] - eXclude track(s) side 0 only  [None]
            X1=track[,to_track] - eXclude track(s) side 1 only  [None]

    '*' options require FDC supporting four physical drives (most don't)

          Details of the meaning of most command line options can  be  found
          in  "MAIN MENU COMMANDS / Settings"  in  the  description  of  the
          corresponding Settings menu options.

          1.3.1 Command Files

             You can place commonly used command line options  into  a  file
             with a .CMD extension,  and activate all of the options in that
             file by specifying the file name on the command  line.  Options
             must occur one per line.  Blank lines, and lines beginning with
             ';' (comment) are ignored when the .CMD file is processed.

            eg: ; Sample command file for DS in HD drive
                ; 40 Cylinders, double-step, translate 250<>300 kbps
                C=40
                DS=1
                T3=250
                T2=300
    ImageDisk                                                        Page: 5


    2. MAIN MENU COMMANDS

       The following commands are available from the ImageDisk main menu, by
       pressing the bracketed letter in the command name:

       2.1 (S)ettings

          The  Settings  menu  allows  you  to  change   various   ImageDisk
          operational settings.  Use the Up/Down arrow keys to select one of
          the following settings, and press SPACE to change it's value.

          2.1.1 Drive

             Controls which physical  floppy  diskette  (A  or  B)  will  be
             accessed by ImageDisk.

          2.1.2 Cylinders

             Sets the maximum number of cylinders which ImageDisk  will  try
             to access.

             In general:  CYLINDERS should be set to the maximum  number  of
             tracks which can be stepped on your drive.

             During Reading,  ImageDisk will not attempt to analyze or  read
             past this setting.  Note that reading will still end if a track
             is found with no data before then.  (hint:  If you need to skip
             blank tracks, use the eXclusion map)

             During Writing,  this setting has  no  effect.  ImageDisk  will
             attempt to recreate all cylinders that are defined  within  the
             image.

             During Align/Test,  this setting has  no  effect  (stepping  is
             controlled manually).

             When cleaning the heads, this setting controls the range of the
             "scrubing" motion throughout which the heads are moved.
    ImageDisk                                                        Page: 6


          2.1.3 Sides

             Controls how ImageDisk treats the the disk as single or  double
             sided during an analysis. Has effect only for Analysis, Reading
             and manual Formatting of a disk. During Writing, ImageDisk will
             recreate both sides if present in an image.

             Available settings are:

             AS ORIGINAL :  ImageDisk will examine the disk to determine  if
             the second side contains data.

             ONE : Useful to prevent ImageDisk from detecting Side1 data for
             previously used disks with valid  but  unrelated  data  on  the
             second side. Also speeds up analysis of single sided disks.

             TWO :  Use this to force ImageDisk to try  and  read  a  second
             side.

          2.1.4 Double-Step

             Setting this option ON causes ImageDisk to  step  two  physical
             tracks for each logical track on the disk.  This  is  necessary
             when reading 48tpi (40 track)  5.25" disks on 96tpi  (80 track)
             drives.  QD/HD drives have twice as many tracks within the same
             diskette area as DD drives.

             Setting the option  OFF  causes  ImageDisk  to  step  a  single
             physical track for each logical track in the image.

             The setting AS ORIGINAL means that ImageDisk will  examine  the
             disk and determine if  double-stepping  is  required.  This  is
             available for READING only - when WRITING a disk,  you MUST set
             this option to either  ON  or  OFF.  (The  correct  setting  is
             determined by the type of drive you  are  using  and  the  disk
             image you are writing - in general,  if the disk image  has  40
             tracks in it, and you are using a QD/HD floppy drive,  you will
             need to turn this option ON - you may also  need  to  select  a
             data rate translation).
    ImageDisk                                                        Page: 7


          2.1.5 R/W gap & Format gap

             The GAP lengths cannot be read from the  disk,  and  using  the
             wrong length can result in an unreadable  copy.  Unfortunately,
             determining the correct gap length can be "magic science".

             CALCULATED will use suggested values from the NEC  databook  if
             it exists for the disk format being used, otherwise an estimate
             is made based on the total track data  size,  sector  size  and
             number of tracks/sector.  This may  not  be  correct,  and  may
             result in a bad disk,  or one which cannot be written.  I  have
             therefore provided the option  to  force  specific  gap  length
             settings.

             If you have problems,  try increasing/decreasing the calculated
             value Note that in general,  the R/W gap must be less than  the
             FORMAT gap. FORMAT = total gap between sectors, R/W = gap after
             READ/WRITE - and should fall somewhere in  the  middle  of  the
             FORMAT gap.

             Sometimes when a disk is made with  an  incorrect  inter-sector
             gap size, it will read fine, however attempts to write the disk
             will corrupt it.  This is because the inter-sector gap  is  too
             small,  and the partial gap written at  the  end  of  a  sector
             overflows into the next sector.

             If you find this is happening,  and you are unable to determine
             good gap size values,  another solution is to simply  copy  the
             entire disk on the target system - this should restore  all  of
             the gaps to the correct sizes as  determined  by  your  systems
             disk driver.

          2.1.6 Format Fill

             This is the byte value used to fill freshly formatted  sectors.
             Normally,  this gets replaced when the sector data is  written,
             howver any sectors marked as  "unavailable"  in the image  will
             remain filled with this value when it is written to a disk.

             This setting also establishes  the  sector  content  for  disks
             which are low-level formatted (only) with the Format command.
    ImageDisk                                                        Page: 8


          2.1.7 Full Analysis

             To save time, normally when ImageDisk has analyzed a track,  it
             performs only a  "quick check"  when moving to the next track -
             If the transfer rate, density and sector size are the same,  it
             assumes the track will be the same as the last and proceeds  to
             read the sectors.  It will perform a full analysis only if  the
             parameters change,  or it encounters read errors on the  sector
             data.

             This option causes ImageDisk to perform a full analysis on each
             track - This increases the time needed to read a disk,  but may
             be required for disks with missing or oddly-numbered sectors on
             some tracks,  or sector head/cylinder values which do not match
             the physical track position on the disk.

          2.1.8 Interleave

             This controls how ImageDisk determines the Interleave factor of
             the disk being read or  written.  ImageDisk  trys  to  discover
             Interleave factor by reading the sectors ids passing under  the
             head  after  an  index  pulse,  however  for  disks  which  are
             difficult to read, this is not reliable.  The following options
             are available:

             AS READ :  Sectors are read/written in exactly the  order  that
             was encountered on the original disk/image file.

             BEST  GUESS  :  Examines  sector  order  and   determines   the
             interleave factor which most closely  matches.  Writes  sectors
             from lowest with this calculated interleave.

             1-99 : Writes sectors from lowest with specified interleave

             2.1.8.1 Interleave factor (skew) explained

                Many systems offset the physical sectors written to a track,
                so that extra sectors occur  between  sequentially  numbered
                sectors,  providing extra time for the CPU to  process  data
                between sequential reads.  For example,  consider a 9-sector
                disk:
                    1:1 Interleave:   1   2   3   4   5   6   7   8   9
                    2:1 Interleave:   1   6   2   7   3   8   4   9   5

                The 1:1 interleave disk will require only one disk  rotation
                to read all sectors,  but only if the CPU is fast enough  to
                be ready for a new  sector  IMMEDIATELY  after  reading  the
                previous one.  If the CPU is not that fast,  it will take  9
                revolutions.  The 2:1 interleave disk takes two  revolutions
                to read all sectors,  but it allows an extra "sectors worth"
                of time between reads.
    ImageDisk                                                        Page: 9


          2.1.9 Retries

             This controls the number of times that a disk operation will be
             retried.

             After one set of retries,  ImageDisk will  normally  re-analyze
             the  disk  to  determine  of  the  track  format  has  changed.
             Retries=0 is a special case which prevents this from happening.
             This is useful if you want to quickly scan the disk to  extract
             readable sectors only.

          2.1.10 Data rate translations

             Data rate translation allows you to try to recreate a disk on a
             different drive type from that on which it was originally read.

             The most common/useful translations are:

                250 -> 300      = Read on 5.25 DD, write on 5.25 HD **
                300 -> 250      = Read on 5.25 HD **, write on 5.25 DD

            ** Normally you would also enable Double-Step on the HD drive.

             You can see the transfer  rates  in  an  image  with  the  IMDU
             utility.

       2.2 (R)ead

          Prompts for an image filename,  and a comment record,  then  reads
          the disk as defined by current settings into the image file.

       2.3 (W)rite

          Prompts for an image filename,  then writes the disk as defined by
          current settings from the image file.

       2.4 (A)lign/test

          Performs diagnostics by continuously reading  sector  IDs  passing
          under the drive head. For each sector ID, outputs:

                <cylinder>  <head>  <sector>  <#match>  <#fail>

          #match and #fail are updated after each full revolution  and  show
          the number of ID's on the track which MATCH the physical cylinder,
          and the number of ID's which DO NOT MATCH the physical cylinder.

          At each revolution,  a tone also sounds which is higher  in  pitch
          when more matching ID's are found. This allows you to adjust drive
          alignment by ear.

          The following indicators are updated in real-time at  the  top  of
          the screen:
                    F=fault         R = ready       D = double-sided
                    W=write-protect Z = track-0
    ImageDisk                                                        Page: 10


          2.4.1 Alignment/test Commands

             The  following  command  characters  can  be   entered   during
             Align/Test:

                A   - re-Analyze track
                B   - toggle Beep on/off
                D   - read Data from all sectors on track
                F   - Format diskette track
                H   - toggle Head 0/1
                I   - write $CnHn.IMD with track data (must do 'D' first)
                P   - set format/write Parameters
                R   - recalibrate to track zero/Reseek current track
                S   - toggle single/double Stepping
                W   - Write data to all sectors on track
                Z   - recalibrate to track Zero (and stay there)
               0-9  - seek to track 'n'*10 (00 to 90)
               +/-  - seek +/- one track from current position
                X   - eXit disk alignment/test function.

       2.5 (C)lean

          Although I do not generally recommend the use of "Cleaning Disks",
          sometimes you don't have time to remove and disassemble the  drive
          and these are a required immediate solution to dirty heads.

          When prompted, insert a "wet" cleaning disk and press ENTER.

          This function will  "scrub"  the disk head back  and  forth  in  a
          zigzag pattern.

          NOTE:  Make sure that CYLINDERS under Settings is set to match the
          number of physical cylinders on your drive.

       2.6 (T)est RPM

          This  function  calculates  the  revolutions  per  minite  of  the
          diskette drive.  Note that this is a simple function which employs
          only the standard DOS 55ms timer tick - The  results  will  become
          more accurate the longer you allow the test to run.

          Note that the  result  is  cumulative,  and  will  not  accurately
          reflect changes to the drive  speed.  If  you  are  adjusting  the
          drive,  press  SPACE  to  restart  the  calculation   after   each
          adjustment.
    ImageDisk                                                        Page: 11


       2.7 Track e(X)clusion map

          Sometimes it is desirable to exclude certain tracks  when  reading
          an  image  (Unreadable,   Unformated,   incompatible   with   your
          controller).

          This function allows you to select  tracks  to  exclude  from  the
          image when reading/writing.  Note that tracks not occurring in  an
          image will NOT be formatted or written when the disk is recreated.

          Use the arrow keys to position the cursor on the track you wish to
          exclude, and then press SPACE to toggle between:
              = Exclude side 0 only
              = Exclude side 1 only
              = Exclude both sides (entire track)

       2.8 (F)ormat

          Performs a low-level format of a diskette.

          Drive, Sides, Step, Format-fill and Interleave must be established
          via Settings.

          Number  of  sectors/track,  starting  sector  number,  data  rate,
          encoding (FM or MFM) and sector size will be prompted for.

          NOTE: This is a LOW LEVEL format only. ImageDisk does not know how
          to establish a file system  (high level format)  for any operating
          system.  If you want to automatically create high-level  formatted
          disks for a certain system the easiest thing to do is  to  Read  a
          freshly formatted disk and create copies from that image.
    ImageDisk                                                        Page: 12


    3. FLOPPY DRIVE TYPES

       There are many drive types that can be connected to a PC.  Aside from
       physical media,  the charactistics which affect how a disk is read or
       written are: Number of Cylinders, Rotation speed and Transfer rate.

                    Drive type      Cyls    Rpm     Rate
                    ---------------------------------------
                    5.25" DD        40      300     250
                    5.25" QD        80      300     250
                    5.25" HD        80      360     500/300
                    3.5"  DD        80      300     250
                    3.5"  HD        80      300     500/250
                    8"              77      360     500

       Understanding these parameters and how they relate to  the  different
       drive types is very important to using ImageDisk effectively.

       3.1 5.25" Double Density

          This is the standard 5.25"  drive on most classic systems.  It has
          40 tracks,  rotates at 300 RPM,  and transfers at a  rate  of  250
          kbps.

          This  gives  it  a  normal  formatted  capacity  of   about   4600
          bytes/track,  which  gives  a  total  disk  capacity  of:  4600  x
          40(Tracks) x 2(heads) = about 360k bytes.

       3.2 5.25" Quad Density

          This drive is  very  simlar  to  the  5.25"  DD  drive,  the  only
          difference being that it  has  80  cylinders  instead  of  40.  It
          rotates at 300 RPM, and has a data transfer rate of 250 kbps. This
          makes it electrially identical to the 3.5" DD drive.

          This  gives  it  a  normal  formatted  capacity  of   about   4600
          bytes/track,  which  gives  a  total  disk  capacity  of:  4600  x
          80(Tracks) x 2(heads) = about 720k bytes.

          The 5.25" QD drive is quite uncommon on PCs, however it does occur
          on some classic systems.

          This drive can read 5.25" DD format disks by enabling Double-Step.
          Please read the note regarding track width when writing.
    ImageDisk                                                        Page: 13


       3.3 5.25" High Density

          This drive has 80 cylinders, rotates at 360 RPM,  and transfers at
          a rate of 500 or 300 kbps.

          At 500kpbs it has a formatted capacity of about 7600  bytes/track,
          which gives a total disk capacity of 7600 x 80(Tracks)  x 2(Heads)
          = about 1.2M bytes.

          The 300kbps data rate is for compatibility with DD/QD drives.  Due
          to the higher rotational speed  (360 RPM),  300kbps results in the
          same bit density as 250kbps on the slower (300 RPM) drives.

          At 300kpbs it has a formatted capacity of about 4600  bytes/track,
          which gives a total disk capacity of 4600 x 80(Tracks)  x 2(Heads)
          = about 720k bytes.

          This drive can read and write 5.25"  QD format disks,  however  it
          will do so at a transfer rate of 300kbps.  To create a true  5.25"
          QD image you must translate 300kpbs to 250kbps  when  reading  the
          disk, and 250kbps to 300kbps when writing the disk.

          This drive can  read  5.25"  DD  disks  by  enabling  Double-Step,
          however it will do so at a transfer rate of 300kbps.  To create  a
          true 5.25"  DD image you must translate 300kpbs  to  250kbps  when
          reading the disk, and 250kbps to 300kbps when writing the disk.

          Please read the note regarding track width when writing.

       3.4 3.5" Double Density

          This drive has 80 tracks,  rotates at 300  RPM,  and  has  a  data
          transfer rate of 250kbps, which makes it electrically identical to
          the 5.25" QD drive.

          This  gives  it  a  normal  formatted  capacity  of   about   4600
          bytes/track,  which  gives  a  total  disk  capacity  of:  4600  x
          80(Tracks) x 2(heads) = about 720k bytes.

          The 3.5" DD drive is quite uncommon on PCs,  however it does occur
          on some classic systems and a few early PS/2 models.
    ImageDisk                                                        Page: 14


       3.5 3.5" High Density

          This drive has 80 tracks,  rotates at 300  RPM,  and  has  a  data
          transfer rate of 500kbps or 250kbps.

          At 500kpbs it has a formatted capacity of about 9200  bytes/track,
          which gives a total disk capacity of 9200 x 80(Tracks)  x 2(Heads)
          = about 1.5M bytes.

          The 250kbps data rate is for compatibility with DD drives. At this
          data rate, the drive functions exactly as a 3.5" DD drive.

          At 250kpbs it has a formatted capacity of about 4600  bytes/track,
          which gives a total disk capacity of 4600 x 80(Tracks)  x 2(Heads)
          = about 720k bytes.

       3.6 8" Floppy Drive

          The 8"  drive is rarely found on a PC however it  occurs  on  many
          classic systems.  It has a different connector than PC drives, and
          you will need to make an adapter to connect it.

          This drive has 77 tracks,  rotates at 360  RPM,  and  has  a  data
          transfer rate of 500kbps.  Aside from being three cylinders short,
          it is otherwise very similar to the 5.25" HD drive.

          Unlike the other disk types,  8"  diskettes are physically  either
          single or double sided - the difference being the position of  the
          index hole.

          A single-sided disk has a normal formatted capacity of about  7600
          bytes per track which gives a total disk capacity of approximately
          7600 x 77(Tracks) = about 600k bytes.

          Double sided disks have twice this or about 1.2M bytes.

          Some 8"  drives may have a TG43 signal issue when  used  on  a  PC
          floppy controller.

       3.7 Writing 40 track disks on 80 track drives.

          An 80 track drive has a narrower  track  width  than  a  40  track
          drive, which means that the track laid down by the head is thinner
          than that laid down by the head in a 40 track drive.

          When writing a disk in an 80 track drive which has previously been
          written on with a 40 track drive,  some portion of the original 40
          track data will remain at the edges of the new thinner track.

          If you then attempt to read the disk in a 40 track drive, the head
          will see two conflicting signals which may cause read errors.
    ImageDisk                                                        Page: 15


       3.8 Easy/Cheap 8" drive adapter

          Begin with an ISA bus connector from an  old  PC  -  this  is  the
          correct spacing for the 50 pin 8" drive, but too long. Cut down to
          50 pins.

          Salvage a 34 pin edge connector from a dead 5.25" drive - look for
          one which has a  "ground plane"  connecting the odd numbered pins.
          Leave  about  1/2  inch  of  board  under  the  connector,  remove
          components and carefully cut tracks to insure that the even number
          pins are isolated from the remainder of the board.

          Scrape away the solder mask to bare the ground plane. Position the
          "board" between the rows of pins on the 50 pin connector, centered
          from each end with the ground plane against the odd numbered  pins
          of the 50 pin connector.  Solder the odd pins to the ground  plane
          and add wire extensions to insure that  all  25  pins  are  joined
          together.

          Using 30 gauge "wire-wrap" wire,  and being careful to only solder
          to the very inner  end  of  the  "fingers"  on  the  34  pin  edge
          connector,  connect the  even  numbered  pins  according  to  this
          pinout:

            PC(34p)   8"(50p)   Description
                        2       TG43        (see Note)
                4       16      In use
                8       20      Index
                12      26      DS1(PC) -> DS0(8")
                16      18      Motor ON/Head Load          All Odd
                18      34      Direction   (Note)          numbered
                20      36      Step                        pins are
                22      38      Write Data                  ground.
                24      40      Write Gate
                26      42      Track 0 detect
                28      44      Write Protect
                30      46      Read Data
                32      14      Side1 Select
                34      12      Ready

          You will now have an adapter which can be plugged onto an 8" drive
          and allows you to connect to a standard 34 pin 5.25" PC cable.

          NOTE:  This pinout connects DS1 on the PC  (the standard for  both
          drive A or B with a twisted cable) to DS0 on the 8" drive. You can
          leave the 8" drive jumpered as Drive-0, and connect it as either A
          or B at the appropriate position on the PC cable.
    ImageDisk                                                        Page: 16


          3.8.1 Track > 43

             Some 8"  drives require a signal called "TG43"  which indicates
             that the drive is positioned to a  cylinder  greater  than  43.
             This is used to reduce the write current on inner cylinders.

             The diskette controller in the IBM PC  does  not  provide  this
             signal, which causes write problems on the inner tracks of some
             8" Drives.

             There are three possible solutions:

             3.8.1.1 Operating without TG43 signal

                Some drives do not require TG43.  Examine the control  board
                on your drive. If Pin 2 of the 50 pin interface connector is
                not connected, then your drive does not require TG43.  If it
                is connected,  the drive MAY require TG43 - it may also be a
                jumper  selectable  option,  please   consult   your   drive
                documentation.

                Since TG43 is used only during WRITE operation,  you will be
                able to read 8" disks.  Writing may fail or be unreliable on
                inner tracks.

                You can also try tying TG43 permanently LOW or HIGH ...  One
                or the other may allow you to create  disks  which  although
                not correct,  MAY be readable  and  can  be  copied  on  the
                destination computer to create correctly written disks.

             3.8.1.2 TG43 via modified drive cable

                The  floppy  control  chip  in  the  PC  provides  TG43  and
                DIRECTION on the same signal.  When  moving  the  head  this
                signal means DIRECTION.  When writing the signal means  TG43
                (reduce write current).

                IF your disk controller does not  "remove"  TG43 from pin 18
                of  the  interface  during  write,  and  IF  your  drive  is
                compatible with the multiplexed signals,  then  you  MAY  be
                able to provide TG43 to your drive just by  connecting  both
                Pins 2 (TG43) and 34 (DIRECTION)  of the 50 pin 8" interface
                to pin 18 (DIRECTION) of the PC interface.

                Note that although this works with some drives,  it does not
                meet the floppy  interface  standard  which  requires  these
                signals to be driven separately.  Some drives will not  work
                in this configuration.
    ImageDisk                                                        Page: 17


             3.8.1.3 TG43 via parallel port

                If necessary, the TG43 signal required by some 8" drives can
                be generated with the parallel port, using this command line
                option:

                    P=pport[,Cylinder[,wf,wr]]

                    pport       = Parallel port 1-3 or hex address  [None]
                    Cylinder    = Cylinder above which to reduce WC [43]
                    wf          = Value to write for full WC        [F0]
                    wr          = Value to write for reduced WC     [0F]
    ImageDisk                                                        Page: 18


    4. TIPS AND TRICKS

       4.1 PC floppy controllers are DIFFERENT!

          The floppy disk controller varies widely from one PC  to  another,
          and MOST PCs  have  limited  controllers  designed  only  for  the
          formats  used  on  PC  disks.  Many  controllers   cannot   handle
          single-density, or lock correctly with the small gaps used in some
          non-PC formats.

          In developing ImageDisk, I have tested with dozens PCs,  and found
          that only a few of them could read and write all the mixed density
          formats that I was able to make work.  Some  could  read  all  the
          formats  (with a high number of recoverable errors)  but could not
          write them all. The remainder could not even read all the formats.

          What this means is that you may have to try a number of  different
          types of PCs before you find  one  that  makes  a  good  ImageDisk
          system.

          These are the PCs/Mainboards which I have tested that worked  best
          with ImageDisk:

            AOPEN:      AP5T, AP5VM, MK33
            INTEL:      SE440BX2(!), D815EEA2(!)
            IBM:        Pro300A_AFP(!)
            COMPAQ:     Prolinia 4/33

          (!)  These boards only provide  a  drive  A:  select  on  the  FDC
          connector which means that  you  CANNOT  HAVE  A  DRIVE  B:  (very
          annoying).

          In all cases, the mainboards integral floppy controller was used.

       4.2 Slowing the drive

          The 765 FDC used in the IBM PC has limitations which are  stricter
          than the WD 17xx/27xx controllers used in  many  vintage  systems.
          One such limitation is that the 765 cannot handle the smaller  gap
          times used on some disks, and can have trouble reading them.

          A useful trick is to slow down the drive to around 290 RPM -  this
          often allows enough extra time that the 765 controller can  handle
          the disk.

          Many disk drives have a potentiometer on the motor control circuit
          board which allows adjustment to the drive speed.  You can use the
          Test RPM function to check your drive speed.
    ImageDisk                                                        Page: 19


       4.3 Identifying an image

          If you receive a .IMD image and do not know what it  contains,  or
          what type of drive it should be created on,  you can use the  IMDU
          utility to learn more about the image:

          - Hopefully the COMMENT shown at the top of the listing will  tell
            you what is contained in the image.

          - The summary near the end will show the number of tracks of side0
            and side1 information.  If the disk contains only side0  tracks,
            then it is single-sided.

          - Look at the total number of cylinders for each side, normally:
                40 = 5.25" DD
                80 = 5.25" QD, 5.25" HD, 3.5" DD or 3.5"HD
                77 = 8"

          - Look at the transfer rate, normally:
                250kbps = 5.25" DD, 5.25" QD or 3.5" DD
                300kbps = 5.25" DD, 5.25" QD read on a 5.25" HD
                500kbps = 5.25" HD, 3.5" HD or 8"

       4.4 Writing a 250kbps image on a HD drive

          When an image which was recorded on a 5.25"  DD or 5.25"  QD drive
          at 250kbps is written on a 5.25"  HD drive,  it must be written at
          300kbps to account for the  higher  rotational  speed  of  the  HD
          drive.

          You must therefore use Settings to Translate 250kbps to 300kbps.

          For images containing 40 tracks (DD), you will also have to enable
          Double-Stepping in order to write the image correctly.

          See also the note on writing 40 track disks on 80 track drives.

       4.5 Writing a 300kbps image on a DD drive

          An image which was recorded at 300kbps on a 5.25" HD drive, can be
          written on a 5.25"  DD or 5.25"  QD drive  by  using  Settings  to
          translate 300kbps to 250kbps.

          Note that a QD  (80 track)  image cannot be written to  a  DD  (40
          track) drive.

       4.6 Reading DD/QD images on HD drives

          A 250kbps DD/QD image can be read on a 5.25" HD drive,  however it
          will read at 300kbps due to the faster rotational speed of the  HD
          drive.

          If you plan to give this image to others,  it is recommended  that
          you use Settings to translate 300kbps to  250kbps  before  reading
          the disk.  This will result in an  image  file  showing  the  true
          250kbps nature of the original disk.
    ImageDisk                                                        Page: 20


    5. MISC. Topics

       5.1 PC Diskette Drive Types

          ImageDisk does not know or care what types of drives are installed
          in your PC - it determines the correct transfer rate and  type  of
          stepping required by analysis of the disk.

          When writing a  disk  on  a  different  drive  type  than  it  was
          originally read on,  you may need to  set  a  data  transfer  rate
          translation. For example, if recreating a 5.25" DD disk on a 5.25"
          HD drive, you will need to translate 250kbps to 300kbps.

       5.2 DD Transfer Rate (250kbps <> 300kbps)

          ImageDisk determines the correct transfer rate for your drive when
          reading a disk,  and that  transfer  rate  will  be  correct  when
          writing the disk on the same drive,  however the transfer rate may
          NOT be correct if you write the disk on  a  different  drive  type
          than it was originally read on.

          Specifically: Standard 5.25" DD drives operate at 250kbps, however
          HD 5.25"  drives on a PC operate at 300kbps when  operated  in  DD
          mode  (this is because the drive rotates at 360rpm instead of  300
          rpm - the actual flux density transition rate on the media will be
          the same).

          A DD image read on a DD drive has a data rate of 250kbps. In order
          to write this to a HD  drive,  you  need  to  write  the  data  at
          300kbps. Use settings to select: 250 kbps -> : 300 kbps

          A DD image read on a HD drive has a data rate of 300kbps. In order
          to write this to a DD  drive,  you  need  to  write  the  data  at
          250kbps. Use settings to select: 300 kbps -> : 250 kbps

          When reading DD in a HD  drive,  I  suggest  setting:  300kbps  ->
          250kbps The image will now indicate the normal  DD  data  rate  of
          250kbps  (even though it was read  on  the  HD  drive),  and  will
          recreate correctly on a DD drive - HD users will have to set:  250
          kbps -> | 300 kbps.

       5.3 Double Stepping

          Although ImageDisk can determine that Double-Stepping is  required
          when reading a disk (48tpi disk in 96tpi drive),  it does not know
          what types of drives you are using, and therefore cannot tell when
          Double-Stepping is required when writing a disk.

          You must therefore set the Double-Stepping option  correctly  when
          writing an image back to a disk.
    ImageDisk                                                        Page: 21


       5.4 Gap Lengths

          As far as I can  tell,  determing  the  correct  inter-sector  Gap
          length is mostly  "Magic Science"  ...  The NEC databook  provides
          tables of suggested gap lengths for common sector formats, however
          no material appears to exist documenting how to calculate the  gap
          lengths for non-standard formats.

          Please read the Notes on Gap Length under Settings.

       5.5 Differences from TeleDisk

          TeleDisk is a disk image program  from  a  company  called  Sydex.
          Until now,  it has been the only available means  to  archive  and
          share disk  images  for  classic  computers,  and  it  has  become
          something of a de- facto  standard  for  this  purpose.  Sydex  no
          longer supports TeleDisk,  and is requesting that  it  be  removed
          from distribution. If you are familier with TeleDisk - please note
          the following:

          - ImageDisk does not try to do everything for you - if  you  don't
            know what you are doing,  TeleDisk will probably work better for
            you. ImageDisk has more user controllable settings, and can do a
            better  job  of  extracting  and  recreating  disk  images  when
            properly configured.

          - ImageDISK does not quietly generate garbage when  sectors  occur
            on the disk but cannot be read - ImageDisk will report all  read
            and write errors in the main screen log.

          - ImageDisk marks within the image when  a  sector  could  not  be
            read.
            See: ImageDisk Utility.

          - ImageDisk has a documented image file format,  which means  that
            you always have the option of exploring other means to  recreate
            a disk This is a MAJOR  problem  with  TeleDisk,  and  the  main
            reason that I created ImageDisk.

       5.6 256 Tracks / 255 Sectors?

          All too often, we find a product in which some arbitrary limit has
          been imposed based on  "current standards",  that causes  problems
          with future enhancements to that standard - a good example of this
          is the floppy disk controller chips designed in the era of the  77
          track 8"  drive which generate an error if recalibrating the  head
          to track zero fails after 77 steps  (this does not work on  an  80
          track drive).

          In designing ImageDisk,  I have chosen to provide support for  all
          of the capabilities of the 765 FDC. This means that as many as 256
          tracks,  and 255 sectors/track are configurable.  It's not that  I
          expect such floppy drives will exist,  however it is  less  likely
          that ImageDisk will become "useless"  because I chose an arbitrary
          limit.
    ImageDisk                                                        Page: 22


       5.7 Aligning a drive

          To properly align a disk  drive,  you  need  a  special  alignment
          diskette and an oscilloscope,  however with ImageDisks  Align/Test
          function,  you can usually  get  "close  enough"  without  special
          tools.

          NOTE:  If you don't know what you are doing,  you can damage  your
          drive,  your PC and possibly yourself - Attempt this only  if  you
          are familier  with  and  comfortable  working  on  mechanical  and
          electronic hardware.

          When you execute the (A)lign/Test function, ImageDisk will enter a
          continuous read loop, providing a running display of the number of
          sectors read which match the currently seeked track  ID,  and  the
          number read which don't match.  There is also  an  audible  "beep"
          which increases in pitch the more matching sectors are found.

          How you physically adjust head alignment varies from one drive  to
          another. For some you loosen the stepper motor and rotate it.  For
          others,  you loosen the whole head carrier assembly and  there  is
          either a worm-screw or a slotted  cam  which  moves  it  back  and
          forth.

          To "best guess"  align the drive,  start with a diskette formatted
          on a known good drive. Seek to various tracks, and adjust the head
          position for the highest audible tones.  Note the limits where the
          tone starts to drop, and assume "dead center" between those limits
          is the best alignment point for that track.  Do  this  at  several
          tracks  over  the  range  of  head  movement  and  find  the  best
          compromise for all positions.  Confirm your results  with  several
          other known good diskettes from other sources.

          You should also check the track-zero  detect  switch.  During  the
          Align/Test function,  ImageDisk will show you the  status  of  the
          track-0 sensor at the top of the screen.  Make sure that it  comes
          ON when you step to track 0,  and goes OFF when you step to  track
          1. If not, you may have to adjust the sensor position.

          Note that if you have  either  the  alignment  or  track-0  sensor
          wrong,  you may not be able to adjust the other correctly.  If the
          drive is really bad to begin with,  you may have to  go  back  and
          forth between the two a few tmes in order  to  get  to  the  point
          where you can make the correct adjustments.
    ImageDisk                                                        Page: 23


    6. IMAGE FILE FORMAT

       The overall layout of an ImageDisk .IMD image file is:

         IMD v.vv: dd/mm/yyyy hh:mm:ss          (ASCII Header)
         Comment (ASCII only - unlimited size)  (NOTE:  You can TYPE a .IMD)
         1A byte - ASCII EOF character          (file to see header/comment)
         - For each track on the disk:
            1 byte  Mode value                  (0-5)
            1 byte  Cylinder                    (0-n)
            1 byte  Head                        (0-1)   (see Note)
            1 byte  number of sectors in track  (1-n)
            1 byte  sector size                 (0-6)
            sector numbering map                * number of sectors
            sector cylinder map (optional)      * number of sectors
            sector head map     (optional)      * number of sectors
            sector data records                 * number of sectors
         <End of file>

       6.1 Mode value

          This value indicates the data transfer rate and density  in  which
          the original track was recorded:

             00 = 500 kbps FM   \   Note:   kbps indicates transfer rate,
             01 = 300 kbps FM    >          not the data rate, which is
             02 = 250 kbps FM   /           1/2 for FM encoding.
             03 = 500 kbps MFM
             04 = 300 kbps MFM
             05 = 250 kbps MFM

       6.2 Sector size

          The Sector Size value indicates the actual size of the sector data
          occuring on the track:

            00 =  128 bytes/sector
            01 =  256 bytes/sector
            02 =  512 bytes/sector
            03 = 1024 bytes/sector
            04 = 2048 bytes/sector
            05 = 4096 bytes/sector
            06 = 8192 bytes/sector

       6.3 Head value

          This value indicates the side of the  disk  on  which  this  track
          occurs (0 or 1).

          Since HEAD can only be 0 or 1,  ImageDisk uses the upper  bits  of
          this byte to indicate the presense of optional items in the  track
          data:

             Bit 7 (0x80) = Sector Cylinder Map
             Bit 6 (0x40) = Sector Head     Map
    ImageDisk                                                        Page: 24


       6.4 Sector numbering map

          The sector numbering map contains one byte  entry  containing  the
          physical ID for each sector that occurs in the track.

          Note that these entries may NOT be sequential.  A disk which  uses
          sector interleave will have a sector numbering map  in  which  the
          sector numbers occur in non-sequential order.

          If ImageDisk is unable to obtain all sector numbers  in  a  single
          revolution of the  disk,  it  will  report  "Unable  to  determine
          interleave"  and  rearrange  the  sector  numbers  into  a  simple
          sequential list.

       6.5 Sector Cylinder Map

          This is an optional field.  It's presense is indicated  by  bit  7
          being set in the Head value for the track.

          When present,  it means that the cylinder values  written  to  the
          sectors do NOT match the physical cylinder of the track.

          The Sector Cylinder  Map  has  one  entry  for  each  sector,  and
          contains the logical Cylinder ID for the corresponding  sector  in
          the Sector Numbering Map.

          Reading a disk with non-standard Cylinder ID's  will  require  the
          use of the FULL ANALYSIS setting.

       6.6 Sector Head map

          This is an optional field.  It's presense is indicated  by  bit  6
          being set in the Head value for the track.

          When present, it means that the head values written to the sectors
          do NOT match the physical head selection of the track.

          The Sector Head Map has one entry for each  sector,  and  contains
          the logical Head ID for the corresponding  sector  in  the  Sector
          Numbering Map.

          Reading a disk with non-standard Head ID's may require the use  of
          the FULL ANALYSIS setting.

       6.7 Sector Data Records

          For each sector ID occuring in the Sector Numbering Map, ImageDisk
          records a Sector Data Record - these records  occur  in  the  same
          order as the IDs in the Sector Numbering Map:

            00      Sector data unavailable - could not be read
            01 ...  Normal data: (Sector Size) bytes follow
            02 xx   Compressed: All bytes in sector have same value (xx)
            03 ...  Normal data with "Deleted-Data address mark"
            04 xx   Compressed  with "Deleted-Data address mark"
    ImageDisk                                                        Page: 25


    7. IMDU: ImageDisk Utility

       7.1 Introduction

          IMageDisk Utility  (IMDU)  allows you to manipulate ImageDisk .IMD
          files. The functions which can performed by IMDU are:

            - Display track/sector detail.
            - Compare two .IMD files.
            - Merge two .IMD files, extracting missing tracks and
              sectors from one to complete another.
            - Remove specific tracks/sides.
            - Translate the data rate values.
            - regenerate track data with a new interleave factor.
            - Compress/Expand "all same" sectors.
            - Convert .IMD file to raw binary .BIN format.
            - Extract, Append and Replace the image comment record.

       7.2 Command line options

        Use: IMDU input-image [[merge-image] [output-image]] [options]

        opts:   /B                  - output Binary image
                /C                  - Compress "all-same" sectors
                /D                  - display track/sector Detail
                /E                  - Expand compressed sectors to full data
                /M                  - ignore Mode difference in merge/compare
                /N                  - force Non-deleted data
                /Q                  - Quiet: supress warnings
                /Y                  - auto-Yes (no overwrite prompt)
                AC=file[.TXT]       - Append Comment from file      [none]
                EC=file[.TXT]       - Extract Comment to file       [none]
                F=xx                - missing sector Fill value     [00]
                IL=[1-99]           - reInterLeave(blank=BestGuess) [As read]
                RC=file[.TXT]       - Replace Comment from file     [none]
                T2=250/300/500      - 250khz Translate              [250]
                T3=250/300/500      - 300khz Translate              [300]
                T5=250/300/500      - 500khz Translate              [500]
                X=track[,to_track]  - eXclude entire track(s)       [None]
                X0=track[,to_track] - eXclude track(s) side 0 only  [None]
                X1=track[,to_track] - eXclude track(s) side 1 only  [None]

          In general, IMDU works by reading the input-image, and writing the
          output-image, performing whatever adjustments are specified by the
          options.

          If no adjustment options are made, then IMDU performs a compare of
          the two images. (Adjustment options are: /B, /C, /E, AC=, EC=, F=,
          IL=, RC=, T2=, T3=, T5=, X=, X0= and X1=).

          If three image file names are provided,  IMDU will merge the first
          two,  combining missing data from one into the other and write the
          final combined image to the output file.  Adjustment  options  may
          also be applied during the image merge.
    ImageDisk                                                        Page: 26


          The /B option causes IMDU to remove the comment and all formatting
          information,  outputting what is essentially only the  raw  sector
          content of the disk.  This is useful for many emulators and  other
          disk image manipulation utilities  which  do  not  understand  the
          embedded format information in a .IMD file.

          When using /B, IMDU automatically outputs the sector data in order
          by logical sector number (ie: removes interleave),  however if you
          wish the sector data to be output in some other order, you can use
          the IL= option to re-interleave the output order).
    ImageDisk                                                        Page: 27


    8. BIN2IMD: Binary to Image utility

       8.1 Introduction

          The BIN2IMD utility converts raw binary disk images into ImageDisk
          .IMD format by adding Mode, Cylinder, Head, and Sector information
          to each track/side record.

          BIN2IMD can be useful to convert raw disk images  (such  as  those
          used by many emulators)  into ImageDisk images.  It  can  also  be
          useful in converting images from other sources  -  even  if  those
          images contain embedded format information,  it may be  easier  to
          convert them to raw binary format and then use BIN2IMD to generate
          a .IMD file than it is to try and convert  directly  to  the  .IMD
          format.

       8.2 Command line options

        Use: BIN2IMD input-file output-image [option-file] [options]

        opts:   /1                      - 1-sided output
                /2                      - 2-sided output
                /C                      - write Compressed sectors
                /U                      - write Uncompressed sectors
                /V[0|1]                 - Verbose output
                C=text | @file          - image Comment
                N=#cylinders            - set Number of output cylinders
                DM[s]=0-5               - track Data Mode
                SS[s]=128-8192          - track Sector Size
                SM[s]=n[,n-n][n.#]      - track Sector numbering Map
                CM[s]=n[,n-n][n.#]      - track/sector Cylinder  Map
                HM[s]=n[,n-n][n.#]      - track/sector Head      Map

          The MD=, SS=, SM=,  CM= and HM= options can all be applied to both
          sides, or one side only. Example:
             SM=1-9 <= Both sides
             SM0=1-9 <= Side0 only
             SM1=1-9 <= Side1 only

          It is therefore possible  to  create  disks  which  are  formatted
          differently on one side than the other  (Most  commonly  used  for
          formats which  require  differing  sector  numbering  and/or  head
          mapping on each side).

          As a minimum,  in order to generate an  image,  BIN2IMD  needs  at
          least the following options applied to all sides  that  are  being
          generated:
             N= (always applies to both sides), MD=, SS= and SM=.

          DM= sets the Data Mode, which must be one of:
             0 = 500 kbps FM    \   Note:   kbps indicates transfer rate,
             1 = 300 kbps FM     >          not the data rate, which is
             2 = 250 kbps FM    /           1/2 for FM encoding.
             3 = 500 kbps MFM
             4 = 300 kbps MFM
             5 = 250 kbps MFM
    ImageDisk                                                        Page: 28


          SS= sets the Sector Size, and must be one of:
             128, 256, 512, 1024, 2048, 4096 or 8192.

          SM= specifies the Sector Numbering Map,  which  also  defines  the
          number of sectors occuring on a track.  SM= may consist of any  of
          the following elements:

            number          = Single sector-number
            number1-number2 = Series ranging from number1 to number2
            number.times    = Single value occuring multiple times.

          Multiple elements may be combined into a map  by  separating  them
          with commas:

            SM=1,2,3,4,5,6,7,8,9    <= 9 sectors from 1 to 9
            SM=1-9                  <= Also 9 sectors from 1 to 9
            SM=9-1                  <= 9 sectors from 9 to 1
            SM=1,2-8,9              <= 9 sectors from 1 to 9
            SM=1.9                  <= Sector #1 occuring 9 times **
        ** This (1.9) is actually invalid since sector numbers may occur
           once within a track, however this format is useful in some of
           the other lists.

          The sector mapping you specify MUST match the order in  which  the
          sector data occurs in the binary  file.  If  you  wish  to  create
          images with differing interleave etc.  You must first  create  the
          image with the pysical  data  ordering,  and  then  use  the  IMDU
          utility to re-interleave it.

          HM= specifies a non-standard Head Numbering Map (if not specified,
          all sectors are assumed to have the physical head number encoded).
          The number of HM= entries must match the number of sectors defined
          by SM=.

          Here is an example where a disk is created which logicaly  has  20
          sectors on Side0,  even though they are  physically  organized  as
          sectors 1-10 on Side0, and 11-20 on Side1:

                      SM0=1-10 HM0=0.10 SM1=11-20 HM1=0.10

          NOTE:  The HM0=0.10 isn't strictly necessary,  since  the  default
          head encoded for Side0 would be 0,  however it has  been  included
          for it's descriptive value.

          CM= specifies a non-standard Cylinder encoding.  Very rarely used,
          this option operates similarly to HM=.
    ImageDisk                                                        Page: 29


          The /1 and /2 options are rarely  used.  These  options  exist  to
          inform BIN2IMD that a disk is single  or  double  sided  in  cases
          where it may not be able to determine this from the parameters.

          /2 can be used when both sides are the same, and no Side1 specific
          options have been specified - Use /2 to let BIN2EXE know  that  it
          should generate two side  (You could also just specify  one  Side1
          specific option as the presense of such  an  option  automatically
          sets double-sided).

          /1 or /2 are also used in option files,  when the number of  sides
          to be encoded changes part way thorugh the  disk.  An  example  of
          this might be a disk which has system tracks on Side0 only for the
          first two Cylinders, and is double-sided after that. This is quite
          rare.

          /V controls the output of Verbose  information  detail  about  the
          diskette format being generated.

            /V  = Generate track format summaries only
            /V0 = Generate no detail (Default - use this to turn Verbose
                  detail output OFF within an option file).
            /V1 = Generate detail showing track format and map detail.

          C= Specifies a comment to be included in the image.  A single line
          of text can be specified.  To accomodate the fact that you  cannot
          put spaces in comamnd line parameters, any '~' characters occuring
          in the comment text will be translated to  spaces.  You  may  also
          include the content of a file with  'C=@filename'  - in this  case
          the text file is included with no translation.

       8.3 Mixed format disks - Command option files

          BIN2IMD can create mixed format disks - those in which the  format
          changes from one track to the next.  To do this,  you must specify
          the command options to specify the format into  an  "option"  file
          (type:  .B2I),  with each set of parameters  on  a  separate  line
          preceeded by the Cylinder number where  those  parameters  are  to
          take effect.

          You may also use a command option file to establish commonly  used
          initial format option.  If the first entry in the file is assigned
          for Cylinder 0,  then these options need not be specified  on  the
          command line.

          Blank lines,  and lines beginning with ';' are ignored as comments
          in the command option file.

            ;
            ; Example command option file to demonstrate a 40 Cylinder
            ; double-sided disk which is formatted 10x256 bytes sectors
            ; at 250kbps FM on the first two Cylinders, and 10x512 byte
            ; sectors at 250kbps MFM on the remaining 38 Cylinders.
            ;
            0   N=40 DM=2 SS=256 SM=1-10 /2
            2   DM=5 SS=512 SM=1-10 /2
