40GB or Bust	Volume 4 Number 1 May 15, 2000	RealAudio

by Scott Tilley

Very large hard drives are now available at reasonable cost for computer owners. I recently had the experience of installing a 40GB drive in a Celeron-based PC. What should have been a simple job involving a screw driver and a few disk formatting commands soon developed into major multi-machine surgery, BIOS upgrades, and jumper woes.

It's been nearly two years since I experienced the joy of installing an external SCSI disk drive. Since then, disk capacities have increased enormously. At the same time, prices have fallen so low that extremely large drives are now within the reach of most consumers. I recently decided to add a second internal EIDE drive to a Celeron-based PC. This should have been a relatively simple task, but as is usual with PCs, the simple soon becomes the complicated.

I unpackaged the new 40GB drive, took the metal cover off the PC, and mounted the drive in a free slot beside the existing 10GB drive. I then connected the power cable, the ribbon cables, and set the jumper of the new drive as "Slave" (more on this below). The PC was powered up, and I anxiously waited while the system booted ... and promptly hung right after the memory self-test. At first I thought I had forgotten to connect the power, or that I had misconnected a cable, but the root of the problem turned out to be the system's BIOS and the fact that I chose a 40GB drive, rather than the more common 32GB model.

BIOS Blues

The program that sits between the operating system and the hardware is called the BIOS (Basic Input/Output System). The BIOS program is stored in semi-permanent memory on a chip located on the PC's motherboard. Many older BIOS programs impose a 32GB limit on the size of the hard disk they can control. "Older" in this case typically means BIOS versions before June 1999. To get around this problem, you must upgrade your BIOS (assuming an upgrade is available). 

Upgrading your BIOS involves a process called flashing wherein you boot the PC from a DOS-based floppy, run a program that copies a file from the floppy to the PC's motherboard, and hope the power doesn't go out. The copying is actually burning the new BIOS program into EPROM (Erasable Programmable Read-Only Memory) on the PC's motherboard. If the power fails while this upgrade is underway, the flashing process can render your PC totally useless. For this reason, flashing your BIOS is not something that you want to do very often. 

Most PC manufacturers provide BIOS updates on their Web sites. Fixing date routines related to theY2K problem and providing improved device support for migration to Windows 2000 are two examples of upgrades that may require updated BIOS programs.. If you have a generic no-name PC, then getting the BIOS is a little trickier. Most no-name computers are not manufactured by the company you bought it from. They just assemble it using parts they buy from other suppliers. For example, the mini-tower housing, the power supply, the motherboard, and the keyboard might be all that really constitutes the PC from the no-name computer company . They buy the motherboard from another company, and this other company is actually the one who provides the BIOS for the PC. So you are several steps removed from the BIOS supplier in this situation.

I eventually tracked down the motherboard manufacturer, downloaded and installed the latest version of the BIOS for the computer in question, and tried again. The result: the system still hung during the boot cycle. A few phone calls later I eventually found out that even the most recent BIOS for this particular chipset won't solve the 32GB limitation. I was stuck. I could return the drive and purchase a smaller one, I could try the drive in another computer, or I could insert the "Cylinder Limitation Jumper" (CLJ) and use the 40GB drive as if it was a 32GB drive.

Jumpers

I opted for the CLJ test first, to make sure the drive itself was actually working. Most computers support up to four EIDE devices, known as Primary Master, Primary Slave, Secondary Master, and Secondary Slave. Each device is set to function in one of these roles based on jumper settings. By default, drives are shipped for use in single-disk computers, functioning as Primary Master. Since I already had an existing hard drive in the PC, I set the new 40GB drive to function as Primary Slave. The secondary master and slave devices were already installed, as a Toshiba CD-ROM and an Iomega Zip drive, respectively. 

The CLJ jumper is J46, as shown in the picture to the right. When I inserted this jumper and tried the system, low and behold it booted! However, it booted as if the new drive was 32GB, not 40GB. While I was happy that the PC booted at all and that the drive was apparently functional, I was not happy about wasting 20% of the drive's capacity. Since I now knew that the drive itself was working, I decided to try it in another PC, one that uses a different chipset.

Drive Swapping

I removed the 40GB drive from the Celeron-based PC and installed it in a Pentium III-based PC. This PC uses a different chipset and has a different BIOS. Just like before, I reconnected the power cable, the ribbon cables, verified that the jumper of the new drive was set as "Slave", powered up the PC, and anxiously waited while the system booted ... and promptly hung right after the memory self-test. 

Depressed, but not defeated, I went through the BIOS upgrade process again. After the flash was complete, I rebooted the PC and waited to see what would happen. This time, I saw the satisfying phrase "Detecting Primary IDE Master ... Maxtor ..." appear on the monitor. The system booted successfully! 

I chose the Maxtor DiamondMaxPlus because of its large size (40GB), its speed (7200 RPM), and its cost ($279 at the local BestBuy). However, to be used it had to be placed in a different PC -- not the one that I had originally purchased the drive for. Luckily, the Pentium III-based PC already had a second 20GB drive installed, which I then swapped into the Celeron-based PC. The 20GB drive worked fine the first time, since it is below the 32GB BIOS limit.

Before it can be used, the 40GB drive must be formatted. Since the PC is used in a Windows 2000 Professional environment, the drive can remain in a single 40GB partition if desired: the NTFS file system supports volumes of up to 16 exabytes (16EB) in theory, and 2 terabytes (2TB) in practice. Getting to 40GB didn't bust me or the PC, but it wasn't a very smooth upgrade. I hope that the next disk installation I suffer through isn't called "2TB or Toast"!