CONVERTING MICROBEE DISKS TO IMAGES
===================================
This document describes a method for creating disk images from Microbee
floppy disks using suitable Intel x86 PC hardware, OS and some conversion
software.

HARDWARE & OS
-------------
Hardware consists of an x86 PC that is able to read double density, 10
sectors per track of 512 byte sized sectors, and incorrectly formatted
Microbee diskettes (Side 1 bug).  Not all PCs will work, you will need to
use the test utility to find a PC that can do the job.  On some PCs
different floppy cards can be tried.  The ImageDisk tools that will be used
has a web site with a register of known working hardware that may be useful.

The PC should ideally have a hard disk drive, Flash drive, ZIP or LS120 disk
or some other media that can store the disk images created.

To create the images the program used requires a real DOS operating system,
do not run under a Windows DOS prompt or a NT cmd prompt.  A Windows 98 boot
disk may also work.

The other conversion programs can be run on more modern operating systems
and without regard to any special hardware requirements.

APPLICATION SOFTWARE
--------------------
ImageDisk
---------
The software used to convert the disks to images is in a package of tools
known as "ImageDisk".  This provides several DOS programs. The IMD program
in the package is the only program that should need the special hardware and
OS requirements.

The other programs should run under W98 DOS prompt, Windows 2000, XP, Vista
cmd prompt, or on Linux under dosemu.

The version used here was 1.17 and is available from this web page:
http://www.classiccmp.org/dunfield/img/index.htm

Imagetools
----------
Some other conversion tools I wrote can convert the raw disk images produced
from the ImageDisk tools to the "DSK" (CPCEMU) image format and vice versa,
and others that create formatted disk images.  Each tool provided is
available for Windows and Linux.

The tools include:
raw2dsk  - Converts a raw disk image to a "DSK" (CPCEMU) image.
dsk2raw  - Converts a "DSK" (CPCEMU) image to a raw disk image.
mkrawimg - Creates a CP/M formatted raw disk image file.
mkdskimg - Creates a CP/M formatted "DSK" (CPCEMU) image file.
dskinfo  - Dumps information contained in a "DSK" image

The disk tools can be found here:
http://microbee.no-ip.com/uploads/Software/Imagetools/imagetools-1.0.0-bin.zip

MY TEST SET-UP
==============
My testing set-up consisted of the following:

* 386DX33.
* 105 MB HDD.
* 1 x 3.5" HD Floppy drive.
* 1 x 5.25" HD 80T drive.
* 1 x 5.25" DD 40T drive.
* DOS 6.22 bootable from HDD.
* A parallel cable and transfer software.

GETTING STARTED
===============
Checking the PC
---------------
If you have dug out an old PC to do this work it may require the disk heads
to be cleaned.  If you are technically orientated you could remove the drive
and use some cotton cleaning buds and some cleaning alcohol.  Alternatively
use a disk cleaning disk (you can make a 5.25" one) and use the Cleaning
head command in the IMD program.  I found that I had to do regular cleaning
if the last disk I tried to read had a lot of retries.

Check that the PC your going to use is reliable and does not have a bad
floppy drive that may damage your disks.  Use an ordinary disk that has no
signs of damage and place this into the PC and do a complete format on it
(unconditional):

example:

c:\>format a:/u

Check the output from the format command,  we want to see all sectors
are marked as usable.

Examine the disk for any abnormal wear and tear.

Install the ImageDisk software
------------------------------
Install the ImageDisk software on the imaging PC.  I placed this on drive
C:\ It is not recommended to run this software from a floppy drive!

Write protecting disks
----------------------
You should write protect all your Microbee disks before starting the
conversion process just to be safe.

PC Compatibility test
---------------------
Before starting you will need to establish that the PC hardware you intend
to use is suitable.  There is a "TESTFDC" program in the ImageDisk package
to do this, but first this WARNING - It wants to do a test write to the last
5 disk tracks.  You should NOT use any original disks, use a standard IBM
formatted or blank disk.

Use a 3.5" 800K DD or a 5.25" 400K DD disk if you have one.  If your testing
using the 3.5" drive and you only have a 1.44MB HD disk then cover up the
left hand side hole (looking at disk front).  This will make the disk look
like a 800K DD type.

If you have Microbee disks that are HD type you may need to cover the HD
hole to correctly read the disk on a modern 3.5" drive.

Run the test program on the drive you want to use and optionally create a
report file:

c:\>testfdc a: r=reporta.txt

When prompted for a low density media insert the disk and press the ENTER
key.

If prompted for a high density disk press the ESC key to skip.

For 3.5" or 5.25" 40 track drive units we want to see that this part of the
test passed:

Double-Density at 250kbps .... passed

For a 5.25" 80 track (HD) drive unit we want to see that this part of the
test passed:

Double-Density at 300kbps .... passed

The "TESTFDC" program does not appear to test 10 x 512 sectors and while the
above test is useful for knowing what density disks can be read the real
problem appears to be that some FDC controllers don't like the smaller gap
between the sectors, Microbee pushed the limits with 10 sectors per track.
So the real test is just to see if the "IMD" program will make an image. It
will most likely give up on the first track if the disk can't be read.

MAKING IMD IMAGES
=================
The IMD images that are created here are the important ones to archive.  The
IMD images not only contains the disk image but other important information
about the disk, bad sectors, etc.  Any raw images produced from the IMD
image will lose that important information.  so keep your IMD files!

To avoid incorrectly reading a disk we will tell the IMD program exactly how
to read the disk instead of just relying on auto detection.

The auto detection may think a SS80 (CIAB) disk is double sided if side 2 is
formatted and so the image will be in the incorrect format to be used in
emulators, this should be fine though if the IMD image is to be written back
to a new floppy disk.  There may also be problems reading 5.25" disks in 80
track drives so we need to force double stepping.

Unfortunately IMD does not take the image name you want to create on the
command line so you have to enter this interactively when IMD starts.

1) Run the appropriate command line to suit the disk and drive type (see
   below).
2) Press the 'R' key to select the "Read disk into file" option.
3) Enter the name of the image to be created (no extension).
4) Optionally place a comment about the disk into the box,  when finished
   press the ESC key.
5) You will be prompted for the disk to be read.  Insert the disk and press
   the ENTER key.
6) Disk image creation with diagnostics information is started.  When
   completed press the ENTER key to return to the main menu.
7) Press the ESC key to exit or if you want to create more disk images of
   the same disk type then repeat from step 2.

Drive selection
---------------
All the command lines below use drive A: (/A).  Change this to the drive
required for your PC set-up. (i.e. /B /C /D)

Drive differences
-----------------
High density 5.25" drives (80T) operate at 300kbps in double density mode.
Ordinary 5.25" drives (40T) and 3.5" drives operate at 250kbps.  If the
drive your using is an 80T 5.25" HD drive unit then use LR=300 in the
command line.

DS40 (SBC) 5.25" Double sided, 400K
-----------------------------------
if the drive unit is a 40T 5.25" type then use:
c:\>imd /A /H /K LR=250 C=40 S=2

if the drive unit is an 80T 5.25" type then double stepping is required:
c:\>imd /A /H /K LR=250 C=40 S=2 DS=1

if the drive unit is an 80T 5.25" HD type then double stepping is required
and the data rate is 300kbps:
c:\>imd /A /H /K LR=300 C=40 S=2 DS=1

SS80 (CIAB) 3.5" Single sided, 400K
-----------------------------------
c:\>imd /A /H /K LR=250 C=80 S=1 

DS80/DS82/DS84 (Modular/Dreamdisk/PJB) 3.5" Double sided, 800K
--------------------------------------------------------------
c:\>imd /A /H /K LR=250 C=80 S=2 

CONVERTING IMD TO RAW IMAGE FORMAT
==================================
The IMDU.COM program from the ImageDisk package is used to convert the 'imd'
image file to a raw image.  

We will assume for this example the image is from a DS40 (SBC) disk so will
use 'd40' for the raw file name extension.  As this is a DOS program the
file name is '8.3' format.  The raw image file produced can be renamed after
the conversion process.

c:\>imdu myimage.imd myimage.d40 /b

I recommend using the following file extensions when converting to the raw
image format as the Imagetools package will recognise these and know how to
treat each raw image type automatically:

D40: Double sided, 40T DD 512 b/s 10 s/t (SBC)
S80: Single sided, 80T DD 512 b/s 10 s/t (CIAB)
D80: Double sided, 80T DD 512 b/s 10 s/t (Modular)
D82: Double sided, 80T DD 512 b/s 10 s/t (Dreamdisk)
D84: Double sided, 80T DD 512 b/s 10 s/t (PJB)

CONVERTING RAW TO DSK (CPCEMU) FORMAT
=====================================
The raw disk images can be converted to 'dsk' format if desired using one
the programs in the Imagetools package:

>raw2dsk myimage.d40
Creates: myimage-d40.dsk

Stewart Kay
9/11/2007
