ANYDRIVE a tool to fix the Drive-Parameters settings
Version 1.0 27.February 1993
Have you ever tried to install a new Harddisk in your PC and found that the
BIOS did not support it? I was faced with that situation lately. I got advice
to buy a new BIOS or to buy a special controller. All of that costs $ and is
a lot of hassle. The BIOS might not be compatible with your Motherboard etc.
This piece of Software fixes the problem WITHOUT any additional Hardware
and allows you to run your old stable BIOS.
How it works:
When the PC is booted, BIOS sets up Interrupt Vectors (0x41 and 0x46) which
point to the parameters for the Harddisks 0 and 1. DOS picks up the Drive
Information from the adresses given in these Vectors. A normal BIOS sets the
Vectors up to point to a Drive-Table in ROM, but the newer BIOSses that allow
customizable Cyl/Head/Sector settings store the Drive-Parameters in the BIOS
Memory Area at Segment 0x40 and therefore they point to RAM. ANYDRIVE simpy
does the same with the old BIOSes.
Since ANYDRIVE is not resident in ROM some other place was needed for the
Code to built the Drive-Parameters in the BIOS Area. This must be done
before DOS is started because DOS builds up its own parameter blocks from
the BIOS Drive-Parameters.
The only place I could find was the Master Boot Block of the Harddrive. It
contains the Partition-Table for the first Drive but is otherwise empty.
ANYDRIVE inserts Code into the Master Boot Block to set up the
Drive-Parameters in the BIOS Memory area and points the Interrupt-Vectors
(0x41 and 0x46) to the new Parameters. DOS will look it up there and build
its Disk Control-Blocks based on them and not on the settings in ROM.
This means that ONLY after running the Master Control Block will
the Drive-Parameters be correct. This is no problem when booting from the
Harddisk since the Master Boot Block must be executed anyway. But if you
insert a Floppy Disk and then boot the Machine the old BIOS-Parameters will
be in effect! BE CAREFUL!
You can avoid this by deactivating the DOS-Partition in Drive 0. Then the
Master Boot Block will be executed but no active Partition will be found.
ANYDRIVE will ask you to insert a Floppy and then allow you to boot
with the correct Drive-Parameters. This feature is especially important for
the first Boot as we will see later.
Pressing LEFT-SHIFT while booting results in the same becuase it might be
too inconvienient to deactivate the DOS-Partition. I remember that FDISK
doesnt support that yet (Classical Microsoft behaviour).
Hold LEFT-SHIFT while booting and ANYDRIVE will ask you to insert a Floppy
for booting. Remember that there must be NO DISK in the Drive when you boot.
Insert it when asked to.
If you boot from Floppy and you did not have to press a Key to Boot
YOU WILL HAVE THE INCORRECT BIOS-SETTINGS.
Procedure for installing a primary Harddrive:
1. Low Level Format if necessary (Use WDFMT, it allows you to specify all
desired formats.) and perform Surface Scan if desired.
2. Configure some smaller Harddrive-Size in the BIOS Setup.
3. Run ANYDRIVE 0 ......
This will create the Master Boot Block and partition the Drive to contain
ONE partition for all of it. The Partition is not activated!
4. Reboot without a Disk in the Drive. The Master Boot Block will be executed
and since no Partition is active, ANYDISK will ask you for a Floppy
Disk to boot. Insert the DOS Disk and press a Key to boot again.
5. Perform High-Level Format. Change the Partitions if you want.
6. Run FDISK and activate the Primary Partition
7. Reboot from Harddisk. ANYDRIVE will only ask you for a Disk if you
press LEFT-SHIFT while booting.
Procedure for installing for a Secondary Harddrive
1. Run ANYDRIVE 1 ......
2. Reboot from Harddrive and run BIOS Setup. Change DriveType for Second
Drive to something, so BIOS will know that there are two Drives.
3. Perform Lowlevel / Highlevel formatting as usual.
You might choose to run LowLevel Formats before running ANYDRIVE if DOS
or BIOS gives you trouble booting without format.
Please send me $5 if you find this ANYDRIVE useful. This is only possible
for PRIVATE use. If you want to use it commercially or in a company please
contact me first.
(C) 1993 Christoph Lameter, All Right reserved except as explicitly granted
here. You may use the Software for 30 days to test it. Then either delete it
or send $5. The $5 is the fee for using this Program on one PC as long as
you wish. ANYDRIVE does not become your own.
Commercial inquiries welcome.
As usual there is no guarantee that this Software will work. It might not run
because of incompatibility with Software or Hardware. By using this Software
you accept the consquences that it will not work as intended.
Send Check to
Christoph Lameter, 244 N. Oakland Ave#6, Pasadena, CA
You can reach me on
InterNet: [email protected]
If you have any question or if you need support remember that I was not paid
for this program in any way. I am a student right now and cannot afford to
spend long times helping people out without payment.
I am deeply opposed to anyone taking profit from this software without my
participation. Therefore distribution as ShareWare on Disk or CD is only
allowed if the price of a CD is less than $10 and of a Disk less than $1.
Should you find that anyone has sold you this software on any medium
exceeding these prices contact me immediately.
Join the protest against ShareWare ripoffs.