[Ham-Computers] Hard drives and such

[Hsu, Aaron]

Brian,

As noted before, your main concern will be whether or not your current PC
will natively support larger hard drives.  Old PC BIOS limits were 512MB,
then 2GB.  Some currently have limits of 32GB.  The operating system may
also have a limit as to how much drive space it can see and also how much it
will allow in one partition (or "chunk").  Luckily, there are work-arounds
for BIOS limitations, but OS limitations you usually can't overcome.

BIOS Limitations
If your BIOS limits the maximum natively recognized drive size, then the
*BEST* solution is to upgrade the BIOS.  Hopefully, your system has a
flashable BIOS and the motherboard manufacturer has an updated BIOS
available that supports the larger drive sizes.  If available, this is the
method I'd recommend.  An alternative is purchasing a BIOS upgrade from
companies like Unicore.  They specialize in selling uprade BIOS' for just
about any motherboard manufactured.  However, the cost is often high enough
to just purchase a new motherboard altogether.

Another alternative to BIOS limitations is to purchase a UltraATA adapter.
These usually have a built-in BIOS that supplements the system BIOS and
allows access to the full drive capacity.  On top of that, it also allows
you to take advantage of the UltraATA transfer speeds - something your
current system might not support.  A similar solution is using SCSI, but the
costs outweight the benefits here (I'm not SCSI bashing...in fact, most of
my I/O devices are SCSI).

A third alternative to a BIOS limitation is using "drive overlay" software.
This is software that often ships with high-capacity drives to allow a
system to recognize the full capacity of the drive.  It does so by either
"patching" the system drive table or loading a device driver.  Most today
use a device driver in the boot sector of the drive.  I generally *don't*
recommend drive overlays.  Why?  If the boot sector is trashed for some
reason (such as a virus or "FDISK /mbr"), then the drive will not be
accessable until the overlay software is re-installed.  AND, it must be the
same overlay software as different companies utilize different ways of
over-ridding the system BIOS limitation.  If you don't load th overlay
software, then the data useless.  Also, overlay software often does slow
down drive access as all drive activity must now go through the software
rather than by direct access to the IDE adapter.  Hint: if you're moving a
drive from a system that had BIOS limitations to a new system without BIOS
limitations AND the drive had overlay software installed, remove the overlay
software and allow the new system BIOS to natively see the full capacity of
the drive.  Requires a few more steps in the transition, but you'll
definitely be happier with the results.

A last alternative for BIOS limitations is to just use the drive at the max
capacity the BIOS supports.  You'll lose a great deal of the drive space,
but it might be the only solution available.


OS Limitations
Not much will get you around an OS limitation.  If memory serves correctly,
original DOS FAT-12 had a 512MB (?) drive limit and each partition could
only be 32MB in size.  FAT-16 recognized drives upto 2GB and FAT-32 will
recognize upto 2TB.  NTFS5 (Win2K) has a theorectical limit of 2EB and
pratical limits of 2TB.  Of course, if a BIOS limition is in effect, then
whichever is smaller it your max.

You didn't mention what OS you're using.  It could make a difference.  If
you're still running Win95 or Win95A, then you're maxed at 2GB due to FAT-16
limitations.  Win95B, Win95C, Win98 and newer support FAT-32 and will give
you additional drive capacity.  You also didn't mention if the new drive
will replace the old one or supplement the old one (as a second drive).
This might also have a bearing on your decision.

Whichever you decide to do, good luck and make sure to BACKUP EVERYTHING
before proceeding!

  - Aaron Hsu, NN6O (ex-KD6DAE)
    {nn6o}@arrl.net
    {athsu}@unistudios.com
    No-QRO Int'l #1,000,006
    . -..- - .-. .-   ".... . .- ...- -.--"