A SSF (Small Form Factor) desktop class PC powered by the Pentium 2 processor.

Internal view of the GX1 showing the replacement PSU with adaptor

Power Supply replacement

The power supply in this desktop was well over 20 years old, and was in dire need for replacement, since the system had issues remaining stable after adding two PCI cards. Unfortunately with these old Dell Optiplex machines, changing or upgrading the PSU is not an easy task since Dell opted to use a different pinout for their ATX connector, alongside a proprietary connector than provided 3V to the mainboard. Using a regular AT power supply will damage the mainboard since the wiring is completely different, therefore an adaptor is required for a PSU replacement.

6 Pin Dell P10 AUX Connector Adapter (atxpowersupplies.com)

One downside to this adaptor is that it adds additional slack to the ATX main power cable, which was already long to begin with, this means I had to tie up the excess cable and shove it under the CD drive.

There are various other Dell models which use this type of power supply wiring, generally models from the Pentium 2 and 3 era. The website linked has a list of affected models that use this type of power supply.

Seriously! Don’t use a regular ATX power supply without this adaptor!

Operating Systems

The Optiplex GX1 had a range of officially supported operating systems to use;

Windows 98

The go to operating system for PC retro gaming. Whilst its not the most stable operating system in the world, its widespread support and popularity and to an extent charm means it deserves an install. The GX1 has native support for 98, and most likely came preloaded on most shipped systems for this model.

Windows NT 4.0

The GX1 had full driver support for NT4, since it was designed as a business class system to be used in offices, however with limited DirectX support, the games we can run on NT4 is a lot more limited comparted to 98.

IBM OS/2

The GX1 has official drivers for OS/2 Warp 4, I’ve not tried installing on this system, however I am interesting in getting it running on the system since I have only used OS/2 on virtual machines or PCem.

Red Hat 6.2

One of the officially supported GNU/Linux distro, at least going by the Dell driver support page, which offered official downloads for the GX1. I’ve not tried installing Red Hat on this system (yet)

PCI Expansion

This system has 2 PCI slots and 2 ISA slots, a maximum of three cards can be installed because the middle slot is shared between the PCI and ISA

USB 2.0

USB 2.0 4 Port 480Mbps High Speed VIA HUB PCI Controller Card Adapter PCI

A must have upgrade since the USB bus on this system is limited to the 1.1 standard, and maxes out as 12Mbps. VIA still provide Windows 98 drivers for their cards. Plus the 4 extra USB connectors are useful.

Some older motherboards can be picky in regards to the USB chipset used, apparently VIA chipsets are considered more problematic compared to NEC ones, due to the way IRQ’s are handled and reserved with different chipsets.

Which USB 2.0 cards for old motherboards \ VOGONS

Firewire 1394

Firewire 1394a Dual Port – PCI Full Height Card | eBay

Surprisingly Windows 98 supported 1394 Firewire/iLink cards, and drivers for 98 exist for this card. By adding a 1394 card, this become one of the faster interfaces on the PC, the other being the USB 2.0 PCi card. The onboard ethernet maxes out as 100Mbps.

Spare ISA Slot

Not sure what to put here, a modem? Gameport card? (useful since I have a Microsoft Sidewinder that has a Gameport)

Compact Flash Card

Could be used in the slave IDE channel with the correct adaptor, in order to add additional storage, or to install another operating system like one of the many supported OS.

Specifications

OptiPlex GX1 Midsize Managed PC Systems Reference and Installation Guide (dell.com)

Graphics

ATI Rage II – This is the main graphics adaptor built onto the mainboard. Internally it uses the AGP bus and has 4MB of VRAM with the ability to upgrade to 8MB via onboard memory upgrade.

The graphics processor, with the VRAM to the right along with the VRAM expansion slot. The white IDE looking connector to the top right is the ATI video connector and is meant to connect to an ATI MPEG2 decoder.

This graphics card support the ATI CIF 3D API, which was ATI’s graphics library used with some early 3D titles before the widespread adoption of DirectX. Games such as Wipeout, Tomb Raider used this API. This API was only supported on Windows 95 and 98, it had no support for Windows NT, also later ATI drivers versions remove the CIF support.

Chipset

Intel 82440BX

Memory

There are 3 SDRAM slots available, with one slot populated with a 64MB module, and an extra 64MB module was added to the GX1 to bring the memory up to 128MB. According to the Dell documentation, the system can handle a maximum of 768MB of memory.

Desktop

ATi RAGE utility, showing information about the onboard graphics

wipEout

Oh my… lets try a different resolution

Ah that’s better, Wipeout running at 640×480

South Park

South Park had a PC port, in addition to the console PSone and N64 releases, running in a higher resolutions with Anti-Aliasing

Driver

ATI CIF

I plan on looking at further ATI CIF powered games, in addition to Wipeout listed above (Driver/South Park are DirectX games)

A full list of CIF supporting games is available here