IBM goes OEM with its Cobalt AT 486BL motherboard

IBM goes OEM with its Cobalt AT 486BL motherboard

By Zatni Arbi

JAKARTA (JP): All right! Finally, I've happily gotten rid of
my old albeit faithful 386 PC. Well, partly. I still have most of
its components, including the case, the two floppy disk drives,
the Orchid Fahrenheit 1280 graphics accelerator card, the
Northgate Omnikey keyboard and one of the two 240 MB Quantum
ProDrive hard disks. All I did was replace the motherboard and
add to the new one a single 16 MB SIMM RAM as well as a new 540
MB ProDrive.

As for the motherboard, I guess I was lucky to be able to
obtain one made by IBM. That's news, isn't it? We all know about
IBM Value Points and ThinkPads, but not many of us were aware
that this computer giant has also been selling motherboards and
subsystems in addition to complete systems and CPUs.

Now, with its notorious tendency to use uncommon computer
jargon, IBM calls its Cobalt AT 486BL a system board instead of a
motherboard (for that matter, IBM also calls a hard disk a 'fixed
disk'). Nevertheless, at a price below Rp 1 million for the
motherboard that comes complete with the CPU, a 80387DX math co-
processor, 256 KB cache, and other goodies that I'll describe
subsequently, you might be surprised to hear that it is a bargain
as well as a masterpiece.

Blue Lightning

The Cobalt AT 486BL System Board that I bought was equipped
with an IBM version of clock-tripled 486 CPU called Blue
Lightning. It came with a heat sink. Again, not wanting to use
the more commonly known jargon, IBM calls the chip a "triple
clocked" CPU instead of the more commonly used "clock-tripled"
(this is for you linguists out there to figure out). Anyway, I
wrote about this clock-tripled generation of CPUs some months
ago. In fact, IBM beat Intel in releasing clock-tripled 486 chips
in the market. You might also recall that Intel's version of the
clock-tripled 80486s is called DX4.

Internally, IBM Blue Lightning (BL) CPU on this motherboard
runs at the speed of 75 MHz, while externally it communicates
with the other components at 25 MHz. That gives me a Norton
Desktop's benchmark reading of 144.3 relative to the speed of an
XT and PCTools reading of 74.7. Landmark 2.0 reading is reported
ly 172.74. That should be sufficient for me -- for the time
being.

One thing that distinguishes Intel's DX4 from IBM BL is that
the latter does not have a built-in math co-processor. I did not
have to worry, however, since Cobalt AT 486BL System Board al
ready came with a Cyrix FasMath co-processor.

Accompanied by the co-processor, IBM positioned the 25/75 MHz
BL CPU against Intel 486DX2 66. In case you're wondering what
kind of relationship this computer maker has with the chip maker,
here's the story: IBM and Cyrix have a five-year agreement that
makes the former the primary manufacturer of Cyrix X486
processors. This gives IBM access to 486 technologies.

Should the time come and I no longer find 75 MHz sufficient to
satisfy the next generation application software's hunger for
speed, it seems that I'll still be in a good shape since the
board can accept a Pentium OverDrive chip when it becomes avail
able. Like most other upgradeable motherboards, a zero-insertion-
force, or ZIF, socket is available.

VL-bus IDE

The motherboard has seven 16-bit ISA slots and two VL-bus
slots with bus mastering capability. However, I now have more
free slots than I did on the old, eight-slot 386 motherboard. Two
cards are now no longer necessary: The hard disk controller card
and the I/O card. This motherboard has an embedded IDE controller
that uses the VL-bus specifications. It uses the Appian ADI2 Fast
IDE Interface chip from Appian Technology.

Activating the VL-bus IDE controller required that I install
Appian Disk Accelerator Device Drivers, which was included in the
package. There was a driver for DOS, and there was another for
Windows. The latter automatically turned on the 32-bit Disk
Access of Windows for Workgroups, which makes hard disk operation
even speedier.

At first I forgot to install the drivers and the system worked
as slowly as my old 386. When I turned on the WFWG 32-bit Disk
Access without installing the drivers, the system even crashed.
Only after both drivers had been installed properly did I see the
real performance, and I really said "Wow!". I had some problem
installing Microsoft Office 4.2, though; I had to disable the 32-
bit Disk Access before I could install the entire Office package.
Once installed, I could turn on the 32-bit Disk Access again and
everything became fast once again.

The MR BIOS setup also has an option of 32-bit block transfer
mode, and that further increases the speed of the hard disk
access.

Built-in Anti-virus

On my old boot hard disk there was an unknown virus that
stayed there because I was unable to clean it. Luckily, MR BIOS
has its anti-virus protection for hard disk C:. I really love
this, as viruses are really getting out of hand nowadays --
unless you keep spending your money on new updates of anti-virus
software. The option write protects the main boot sector of hard
disk C:

Combined with BOOTSAFE from PCTools and NAVTSR from Norton,
this protection is perhaps more than enough to guard against
viruses. However, like many other things in life, too much pro
tection can be hazardous as well. I spent 40 minutes helplessly
working with Rescue Disk and SYSTEM.INI after I accessed the CMOS
setup utility just to read its current settings.

Here's what had happened: When I exited the CMOS utility,
NAVTSRW detected that the CMOS was changed and it stopped Windows
cold during boot time. When I tried to restore the CMOS settings
from the Norton's Rescue Disk, the system BIOS halted the system
as it detected some external program was trying to rewrite the
boot and partition table of the hard disk. I shouldn't have
exited the utility, I should have just pressed the Reset button.
Now I had to re-install NDW.

All aboard!

Perhaps one of the features that I liked best was the embedded
controllers. This motherboard comes with an on-board Super I/O
that supports two fast serial ports (ehm, IBM calls them 'Asy
nchronous' ports), one bi-directional parallel port with EPP and
ECP supports. This makes the I/O card no longer necessary.

The board also contains an integrated floppy disk drive
controller that supports two drives, and you can attach one or
two 2.88 MB capacity drives to it.

The package comes with all necessary ribbon cables (see the
accompanying illustration). Increasing RAM capacity could not be
easier; all you have to do is plug in the SIMMs and there's no
jumper or switch that you should tinker with.

All BL CPU chips have a built-in 16 KB internal cache. The
board comes standard with 256 KB of external cache. This is the
minimum of what you should have in a fast 486 system today. If
this amount of external cache turns out to be inadequate for your
applications, you can increase it to 512 KB. But that would be a
fairly expensive upgrade, as it will require 20 ns static RAM
chips.

Easy installation

Installing the board to my full-tower chassis posed no
difficulty at all. Attaching all the internal cables -- such as
the speaker and reset cables -- was easy, too, as everything was
clearly marked. However, when I switched on the PC for the first
time, I got only a series of beeps and nothing else happened.

It turned out that I was using the wrong type of SIMM. I was
using two 8 MB Kingston SIMM. When a 16 MB SIMM was plugged into
SM1, the first slot, everything worked well. This motherboard
supports up to 64 MB of RAM in total with its four 72-pin SIMM
sockets.

The setup utility of MR BIOS also allows us to specify the
boot sequence. It even has the Auto-search option, making it
possible for us to boot from Drive B:. That's another new thing
about this motherboard. Like many other late model boards, we can
also use the Auto-detect utility to find out the correct CMOS
setting for our hard disk, in case it is not a common type or we
don't have the correct parameter settings for it at hand.

Unfortunately, IBM Microelectronics -- the division that makes
this motherboard -- came short of providing us thorough
documentation for this product. There's no troubleshooting
section, so it took me a lot of guessing before I was able to
figure out the wrong type of SIMM. There was no mention of the
anti-virus option, either. The information in the manual is very
minimal. In the CMOS setting there is an option "Daylight Saving"
that we can enable or disable; in the manual there's no
explanation of what it does. The Introduction does warn readers
that the manual is intended to provide general guidelines only.

Final word

The Cobalt AT 486BL System Board is targeted at the lower mid-
range computer market, namely for PCs costing less than US$
2,000.00. More expensive boards from IBM Microelectronics have
integrated VL-bus video graphics controllers as well. Of course,
it would be nice to have SCSI-2 on board as well. For now, if
you're looking for a high-quality and yet reasonably priced
replacement for your 286 or 386 motherboards, this one is highly
recommended. Backed with IBM's three-year warranty, this should
be a sound investment.