Floppy disks and drives will be a necessity for the forseeable future; here
are 5 small utilities to help you get the most out of using yours.

FLOPPARM - Speeds up drive operation by modifying DOS parameters.
FLOPTEST - Tests drive for proper operation. Also does a quick readability
check for every sector of a floppy disk.
FLOPSKEW - Determines optimal skewing for proper formatting. By using the
findings of this program and FDFORMAT you can speed up reading
and writing by 30% every time you use a floppy disk. Formatting
is faster too.
FLOPRPM - Checks a drive's rotation speed for erratic operation.
FLOPINFO - Displays a floppy disk's formatting parameters.

Free software uploaded by the author.

William Luitje
[email protected] or [email protected]

Floppy Tool Kit, Version 1.0
William Luitje
20 January 1994

This is a collection of 5 small utilities which will
help you use your floppy disks better. Since you
probably worry more about how to get better speed and
storage out of your hard disk, this is not likely a
matter of pressing concern to you. However, floppies
are going to be used for quite a while and by spending a
few minutes with these utilities you can make things go
a little bit faster each time you use a floppy.

FLOPPARM
~~~~~~~~
Floppies have been around a long time and have been
improved since they first came out, not only in capacity
but also in their mechanical speed. Unfortunately,
system software can't tell what the best speed to drive
a floppy is and must be compatible with old drives and
so uses conservatively slow parameters. When accessing
a floppy, the BIOS uses a table called the Disk Base
Table for these parameters. This table can be found by
looking at interrupt vector 0X1E. Since this table is
usually set up in RAM by DOS, it is an easy thing to
modify it for modern, fast drives. FLOPPARM will do
this for you conveniently; simply run it with one of the
three arguments SLOW, MEDIUM, or FAST. The parameters
which are affected are:

step rate and head unload time, which are parameters
of the disk controller chip.

head settle time, which is the amount of time taken
after stepping from one track to another to wait for
the head mechanism to stop vibrating.

motor startup time, which is the amount of time
taken to allow the spindle motor speed to stabilize
after it first starts up.

SLOW is provided for compatibility with really old
drives; MEDIUM is somewhat faster than DOS 5; and FAST
is pedal to metal! When run, FLOPPARM displays the
parameters used. If run with no or an illegal argument,
FLOPPARM will display a usage hint and the current
values of the parameters.

FLOPPARM also allows you to specify your own parameters
by using the CUSTOM argument followed by an equals sign
and the four parameters (step rate, head unload time,
head settle time and motor startup time) separated by
commas (no spaces allowed). For example a command
equivalent to FLOPPARM MEDIUM would be

flopparm custom=13,15,1,2

Legal values for step rate and head unload time are from
0 to 15. Legal values for head settle time (in
milliseconds) and motor startup time (in 1/8s of a
second) are from 0 to 255

Note that FLOPPARM is not a TSR and does not take up any
DOS memory; it simply modifies a table which is already
created by DOS. Once you decide which parameters to use,
just put a line invoking FLOPPARM in your AUTOEXEC.BAT
file and enjoy a modest increase in floppy speed.

FLOPTEST
~~~~~~~~
How can you tell if you have set your floppy drive
parameters too fast? I've included a utility which will
seek to every track of the disk, read a sector and
report any errors it finds. The seek pattern is called
a "butterfly test" since it reads the first track, then
the last track, then the second track, then the next to
last track, etc. This will really give the drive a
workout!

This test requires a formatted floppy which has no bad
sectors (FLOPTEST can't tell if an error is due to the
drive not working properly or due to a bad disk). It is
a read only test so it shouldn't change any data on the
disk. There are two parameters: one is the drive
letter and the second is the number of passes to run.
If you get any errors and your floppy is ok then you
should back off one or more of the floppy drive
parameters and test again. Here is an example

floptest a 20

If you are fortunate enough to have more than 2 disk
drives (this applies both to FLOPTEST and to the other
utilities in this package), you can refer to the third
drive as c and the fourth drive as d, even if you have a
hard drive that goes by either of those names. I know
this is confusing but this test operates at the BIOS
level and has no idea what letter DOS has assigned to
your third and fourth floppies. I had a choice of
confusing people who had more than 2 floppy drives or
confusing everybody by making you specify the drive with
a number rather than a letter. That's life.

You can also use FLOPTEST to see if a floppy disk has
any bad sectors. If you run it with only the drive
letter specified, then it will attempt to read every
sector and report any failures. Since FLOPTEST makes
only one attempt to read each sector, it will warn you
if a sector is getting weak.

FLOPSKEW
~~~~~~~~
The most important improvement you can make in using
your floppy drives is to format your disks using
FDFORMAT by Christoph Hochsttter or ATFMT by Oleg
Kibirev. These programs allow almost complete control
over how your disks are formatted. Among other things,
you can put up to 820K on 5" DSDD disks, 1.48 meg on
5" HD disks and 1.7 meg on 3" HD disks. In terms of
speeding up floppy disk transfers, these programs allow
you to control the way sectors are arranged on a track.
This concept is called sector sliding by FDFORMAT and
sector spinning by ATFMT; in the US it's known as sector
skewing. Basically, the idea is that since there is
some mechanical delay in changing heads or tracks it may
be desirable to put the first sector of a new head or
track "later" in the track so the computer doesn't have
to wait for the floppy to make a complete revolution
before that sector can be read. See these programs'
documentation for more details on how this works. The
time savings when reading or writing a floppy can be
substantial when you format it using the optimal skew
parameters and, as an added benefit, formatting is
faster, too.

You can specify head skew and track skew in both
FDFORMAT and ATFMT by the X and Y parameters,
respectively. The DOS FORMAT program does not support
sector skewing at all; this is equivalent to using
FDFORMAT or ATFMT with X and Y both set to zero. But
what values should you use for these parameters? Well,
when FDFORMAT first introduced this feature, I wrote a
batch file which formatted a test disk with various
combinations of the head and sector skew parameters and
then measured how long it took to copy a large file to
the floppy. It took about an hour to run and tested 16
combinations of X and Y values for just one disk format.
FLOPSKEW does the same job in just a few seconds but
tests even more combinations of parameter values.

To use FLOPSKEW, first decide which setting of FLOPPARM
to use and then run FLOPPARM with that parameter since
the step rate and head settle time will both affect
skewing. Then, format a disk of the type and capacity
for which you want to find the optimal skewing
parameters with the X and Y parameters both 0 and
interleave 1. Although FLOPSKEW is a non-destructive
test, you should use a freshly formatted disk to ensure
that these parameters are set correctly, otherwise the
test will give strange results. If you don't specify X
and Y, FDFORMAT and ATFMT default to the correct values
except that they both must use an interleave of 2 for
the 5" 1.44 meg and 3" 1.7 meg formats (and for this
reason it doesn't make sense to use sector skewing with
these formats). DOS FORMAT always formats with no sector
skewing and interleave 1.

Then, simply run FLOPSKEW with the drive letter of the
floppy you want to test as the only parameter. Here is
an example command and its results for a double density
(720K) 3" disk on my system:

flopskew b

Find Optimal Head & Track Skew, Ver 1.0
9 Sectors/Track, 80 Tracks, 2 Sides

Head Skew Times (milliseconds):
X: 0 1 2 3 4 5 6 7 8
Time: 32 54 74 95 116 137 158 178 199

Track Skew Times (milliseconds):
Y: 0 1 2 3 4 5 6 7 8
Time: 232 53 74 95 116 137 158 178 199

Interleave: 1
Minimum skewing parameters: X=0, Y=1
Recommended skewing parameters: X=1, Y=2

First you are shown the format of the test diskette,
then some test results and finally the recommended
skewing parameters. If you are interested in some
technical details about the test you should read the
next few paragraphs; otherwise you can skip ahead to the
next section. Just use the recommended parameters to
format your disks and expect your diskette throughput to
become about 30% faster.

Two tests are run to find the best values for the Head
Skew parameter (X) and the Track Skew parameter (Y).
The head skew test is run by reading the last sector of
the first track using head 0 and then measuring how
long, in milliseconds, it takes to read the first sector
of that same track with head 1. (If the disk is
formatted with only one side this test is not run.) The
track skew test is run by reading the last sector of the
first track using head 1 (if testing a double sided
disk) and then measuring how long it takes to read the
first sector of the second track using head 0. In the
results above, the second line tells how long this took,
in milliseconds, for each of the sectors on the second
track read.

Let's look at the example data to see what we can learn.
First, notice that the times to read different sectors
in the head skew test increase by about 22 milliseconds.
This is just the time it takes to read one sector for
this format. The formula is

sector read time(ms) = 1000 * 60sec/min * rpm / sectors

For this format the drive rotates at 300 rpm and there
are 9 sectors so the time to read a sector works out to
22.2 milliseconds. This formula can be modified to
figure the time to read an entire track by dropping the
final division by sectors. In this case, it is 200 ms.

To determine the best values for X and Y, the program
finds the smallest time and the corresponding number of
sectors skipped from the line above. The data show that
for my system no sectors should be skipped when changing
heads so the optimal head skew parameter, X, is 0.
Typical values are 0 or 1 for most systems. Now look at
the results for the track skewing test; the time to
change tracks without skipping any sectors is 232! This
is the time it takes to read a whole track plus the
sector plus some overhead. In this case the 0 sector
skew provided by DOS format and the default values used
by FDFORMAT and ATFMT yield a big waste of time when
reading or writing multiple tracks. On my system the
optimal track skew parameter, Y, is 1. Typically, it
ranges from 1 to 3 on the systems I have looked at.

Now notice that the program recommends values for the
skew parameters which are 1 greater than the optimal
values. This is because the penalty for choosing a skew
value which is too small is severe: you have to wait a
whole revolution, in this case 200 ms, when changing
tracks. On the other hand, the penalty for having a
skew value which is one too big is only 22 ms. Since
some software may introduce an additional delay when
changing tracks, it is a safe bet to be conservative
when choosing the skew values. If you regularly use
floppies on two computers you should run FLOPSKEW on
both of them and choose the higher of the recommended
skew parameters.

Take the values of X and Y found by the above procedure
and use them to format your floppies in the future. To
make this easy, you can create a batch file, 4DOS or CED
alias, or FDFORMAT or ATFMT configuration file with
those parameters in it. Any time you format a floppy or
read or write a floppy formatted this way it will go
faster.

How much faster? Well, assuming the most likely case
that only track seek is a problem and that the sector
skewing is only off by 1 or 2, then on average the
computer has to wait for a full disk revolution every
second track it reads. Eliminate the wait and you can
reduce the time spent reading and writing by 1/3. When
formatting a diskette, skewing only affects the verify
operation so the time reduction is somewhat less, about
20%.

FLOPRPM
~~~~~~~
If you are having trouble reading or writing diskettes,
especially with a large number of sectors per track, the
problem may lie with the speed at which the drive spins.
FLOPRPM will test this condition for you. Simply place
a formatted disk in the drive you want to test and run
FLOPRPM with the drive letter as the only argument. The
program will then test and display the rotation rate
continuously until you press a key. Normally, all PC
floppy drives will run within an RPM or two of 300
except for 5" HD drives which run at 360. If you are
having problems and the speed of your drive is off by
more than that, you may be able to get better operation
by adjusting the speed of your drive. Unfortunately, no
general guidelines can be given about how to do that
because drives differ in their design.

FLOPINFO
~~~~~~~~
This program simply reads the existing format of a disk
and displays it. With all of the different formats
supported by FDFORMAT and ATFMT it's nice to know what
format a particular disk is. Also, since some of these
formats require a TSR to read, you might want to know if
a particular floppy can be read on another system which
doesn't have a copy of that TSR available. Or, perhaps
you want to quickly find out whether a floppy is HD or
DD.

FLOPINFO takes one parameter, the drive letter. Here is
an example command and response, again for a 720K 3"
disk

flopinfo b

Floppy Disk Information, Ver. 1.0 by [email protected]
OEM Name: IBM 3.3, 512 Bytes/Sector, 9 Sectors/Track, 80 Tracks, 2 Sides
2 FATs, 1 Reserved Sectors, 112 Directory Entries
Total Capacity is 730112

Registration
~~~~~~~~~~~~
While this software may be freely copied and used, I do
request that you register it if you use it. Just send
me either a postcard or some e-mail telling me who you
are and where you are and what you like or dislike about
the program. This is only partially an ego massage for
the author. I enjoy writing useful utilities and have
several other pieces of freeware out floating around the
net so I would like feedback about which of them is
worth expanding and supporting.

This software is intended to be safe to use. All tests
and information programs are read only. About the only
problem you might have is that if you set the floppy
drive parameters too fast you may get read or write
errors. Never the less, in using this software you
assume all risk should anything go wrong. I think that
is pretty unlikely, but, hey, sometimes it rains fish!

William Luitje
2677 Wayside Drive
Ann Arbor, MI 48103
USA

Internet: [email protected] or
[email protected]