Rescuing IBM’s Rarest Desktop From Decades of Silence

Most people have never seen one. Most never will. Yet a compact computer from the late 1980s, stamped with an IBM type number almost no one recognizes, has drawn a small circle of restorers into years of careful work. Roman of Epictronics recently finished another round of repairs on one of them, the IBM 7496 Executive Workstation, turning a once-dead machine into something that boots, stores files, and even plays period sound.

Sometime in the late 1990s, a batch of these mystery units arrived at the Computer Reset warehouse in Dallas, a large facility that serves as a dumping ground for all manner of surplus computer equipment. According to the records, perhaps a dozen of these machines showed up. You would never have known they existed if IBM hadn’t snuck them beneath the radar, as they never made any public announcements about them. Catalogs from the mid-1990s advertized them as some type of luxury PS/2 Model 30, yet they charged a few hundred dollars for the opportunity of possessing one. By the time the warehouse was clearing out the remaining stock, the few that remained had sparked some discreet interest among collectors who recognized what a unique find this was.

The machine itself is simply an all-in-one unit with the identical internals as the PS/2 Model 30. Inside, there’s an 8086 processor at 8 MHz, 640 KB of memory, and the pathetically short-lived MCGA graphics system. A 720 KB 3.5 inch floppy is hidden behind a front bezel. The case still has two expansion slots, but only two due to a riser card, and don’t even think about trying to add a third connector because there just isn’t enough capacity. A small Sony Trinitron CRT is mounted on a swivel above the unit’s base, and the front and back are simply labeled ‘Custom Terminal Executive Workstation’ with no frills. A serial sticker identifies it as a type 7496, but that’s about as far as it goes. It appears to have been part of a limited healthcare trial, probably for nurses stations, because a small footprint is about the only positive thing that comes to mind when thinking of that type of site. It’s difficult to conceive what else it could be, but we do know that it’s a fairly rare creature today, with only a few thot to be alive.

Inside the casing, the floppy drive was a bit of a disaster because the original Alps drive refused to play ball, and it wasn’t just one time; three consecutive defects were layered on top of one another. The cheap surface-mount capacitors had long since given up the ghost, and the 4.7 µF tantalum capacitor had managed to get itself a little dicky. The inductor labeled L2 was essentially burned out. The mechanical switches that indicate the drive whether a disk is in were entirely broken, and you can bet your bottom dollar that it was because they became stuck with some old grease that wouldn’t go away. The read-write heads were even slightly out of alignment. Roman ripped it all out, cleaned every contact, and replaced the faulty capacitors with proper through-hole ones. Then he replaced the burnt-in inductor with a fine one he found on another drive. He was able to steal one of the suitable switches from another mechanism and slid it in, and then he had to get the head assembly working, which he accomplished by easing the head in and out while ensuring the zero-track sensor was in the correct location. After about ten excellent boots, everything all decided to play nice.

With the floppy disk problem resolved, it’s time to make some practical upgrades. However, relying solely on 720 KB floppies gets old quickly. Roman obtained a Glitch Works XT-IDE card and put it to good use, meticulously soldering connectors for the necessary components and connecting the power directly to the compact-flash adaptor. The card fit straight into an empty slot, giving the system real storage. He also inserted a period-correct AdLib clone sound card into the second slot, which sounds fantastic. The power supply, at 100 watts, isn’t the most powerful, but it can handle the extra equipment just well.

When closed, the 7496 appears purposeful, as if it were still a machine on a mission. You can swivel the monitor to see it without straining your neck. The graphics are still not up to par with what people are used to nowadays, but let’s be honest: it will still run the majority of old games and apps. Roman has the whole thing functioning smoothly now; it boots up, loads flash content, and even plays AdLib music when it wants. He went to considerable measures to document each component and issue that developed during the procedure.
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