I am posting in order to summarize the results of a post made by
myself last August.
I would also like to thank everyone who provided me with the findings
necessary for this post.
>Most of the postings I have read recently state that an IDE HD who's geometry
>is 1024*16*63, should equate to 540MB of secondary storage. Based on my
>calculations (1024*16*63*512bytesPerSector/1024bytesPerK/1024KPerMeg), one
>should expect exactly 504MB! This can't be one of those 1024bytes*1024Kbytes
>stories because 504MB=528,482,304bytes. In which case, I understand why one
>would incorrectly state that it gives 528MB. But why 540MB???
>Q1: Once and for all, what is the lowdown?
>I have 2 Conner CF1275A hard drives (1,275GB). Thus far, because my system's
>BIOS does not support Logical Block Addressing (LBA), I have had to used Disk
>Manager for Conner drives in order to create large partitions. This has
>caused me a good deal of grief when I tried to install the Linux OS on a
>second partition of the second drive. The configuration prior to installation
>was as follows:
>DiskA, partition 1 - DOS - 1,275GB
>DiskB, partition 1 - DOS - 840MB (leaving the rest for Linux)
>Linux's version of FDISK reported that ALL of DiskB was already partitioned.
>I was forced to use my ENTIRE second drive in order to complete the Linux
>installation. I suspect that the incompatibility lies between Linux's FDISK
>and Disk Manager, which leads me to Q2.
>Q2: Can I simply replace my BIOS chip with a latter one that does support LBA
>and drop Disk Manager altogether? If so, would I then be able to partition
>the drive into logical drives > 504MB with DOS' FDISK alone? How exactly does
>this work? The folks at American Megatrends say that I could not simply
>replace the chip! A friend of mine says that he did just that for his system!
>Please reply via e-mail.
>Montreal, Quebec CANADA
>"If you can keep your head while those about you are losing theirs,
>consider an exciting career as a guillotine operator!" R.Kipling
problem has been completely resolved. My new configuration is as
follows (all managed by the LInux LOader):
DiskA, partition 1 - DOS - 1.275GB
DiskB, partition 1 - Linux swap space - 16MB
DiskB, partition 2 - Linux File System - 512MB
DiskB, partition 3 - Windows '95 - 777MB
Here are the facts (as I understand them):
A. My calculations were in fact correct.
B. Versions of OnTrack Disk Manager prior to 7.0 are not compatible
with Linux. If you have a special version of Disk Manager for a drive
from a specific manufacturer (eg. Disk Manager for Conner drives), you
should have no trouble registering the product with OnTrack and then
upgrading to version 7.0. The cost is of $25US and the upgrade can be
obtained by calling calling OnTrack at 1-800-752-1333 (612-937-1107).
C. A BIOS chip is very closely tied to a specific motherboard. You
should first try to obtain a replacement from the motherboard vendor.
If you have a fairly common motherboard, you might try calling a BIOS
upgrade vendor found in various trade magazines (eg. Computer
Shopper). One suggestion received suggested that I call TTI
(1-800-541-1943) and ask fro MR.BIOS. Please note that this option is
not always possible. My motherboard is a no-name clone from China so
I was SOL.
D. Due to DOS' limited FAT entry size (16 bits), someone had concerns
regarding the size of the partitions to be used by MS-DOS. The
cluster overhang can become quite significant on large partitions with
generally small files. Please consult the following chart for
resulting cluster sizes (where x is the partition size):
x < 128MB 2KB
128MB < x < 256MB 4KB
256MB < x < 512MB 8KB
512MB < x < 1024MB 16KB
1024MB < x < 2048MB 32KB
2048MB < x 64KB
1. If you have a flash BIOS, simply obtain the most recent version
(which is likely to have the required extension) and perform the
2. Obtain a BIOS upgrade from the motherboard manufacturer or from a
BIOS upgrade vendor;
3. Upgrade your version of Disk Manager;
4. Replace the motherboard with one that supports Logical Block
Addressing (LBA) (this is what I did 486DX2/66->486DX4/100);
5. Purchase an hard drive controller that has an onboard BIOS
extension that supports the features sought (eg. LBA). Apparently,
you do pay a price in lost UMBs going this route;
6. I heard that you could obtain an expansion card that has the
required BIOS extentions.
Once again, many thanks for those involved.
Montreal, Quebec CANADA
Murphy's Eleventh Law:
It is impossible to make anything foolproof, because fools are so ingenious.