In a drafty shed in rural northern California is perhaps the rarest Macintosh ever made: an electronically shielded Mac used by a spy or military agency. The machine appears to be unique, and is so secret, no one knows anything about it.

Sitting on a dusty shelf in an old Boulder Creek, California, barn owned by programmer and author Bruce Damer, the Macintosh SE 30 1891 T at first appears to be a standard all-in-one Mac from the mid-1980s.

But instead of the regular plastic case, the 1891 ST has an all-metal enclosure that has been “Tempest shielded” to prevent it from being snooped on.

Tempest shielding is a standard form of electromagnetic protection defined by the U.S. government for protecting computing equipment from spies. The shielding prevents computers and monitors from emitting electromagnetic signals that can be used to reconstruct sensitive information.

Tempest shielding is not new, and there are a number of companies that add Tempest shielding to Windows PCs for agencies like the National Security Agency, CIA or Department of Defense. Tempest shielding is also used by corporations to prevent industrial espionage.

The 1891 ST is by no means the only Tempest-shielded Mac. A company called TechMatics Technologies used to sell a Tempest-shielded Mac Plus. But the 1891 T does appear to be the only Tempest-shielded Mac made by Apple; and Damer appears to have the only one.

“It’s a black Mac,” said Damer, in reference to the black helicopters used by shady government agencies. “We don’t know who used it—the CIA, the Department of Defense—or where it came from.”

Unlike many other Tempest-shielded computers, the Black Mac looks like an ordinary computer, a move that may have been intentional so as not to attract attention.

But its innocent-looking beige metal case is in fact a Faraday Cage, a metal mesh that stops it from radiating electromagnetic signals. It has a flip-down panel on the front for a Bernoulli drive—a removable drive common at the time.

“The operative could take everything with him at all times,” Damer explained.

The opening for the drive is also protected by an emissions-busting ring of copper coils. Unfortunately, the motherboard of the Black Mac has been removed. So has the panel at the back housing shielded connectors for keyboard, mouse and networking.

Damer plans to display the Black Mac in his private computer museum, the DigiBarn Computer Museum, due to open in July. The DigiBarn will be housed in a converted barn on Damer’s farm, located just over the Santa Cruz Mountains from Silicon Valley.

Very little is known about the Black Mac. As far as Damer knows, the Black Mac is undocumented. There’s no record if it anywhere. Apart from the model number on the front, there are no identifying markings or serial numbers. Damer, who is well-connected in Silicon Valley, has made extensive inquiries about the Black Mac, to no avail.

“It’s the rarest Mac in the world,” Damer said. “This is the only one known. There’s no evidence of any other existing machines out there. There’s no record of it at Apple. But it’s a real Apple machine—it wasn’t made or adapted by another company—so it must have been a classified project.”

Damer said there may well be others, but he has no idea where they’d be.

Damer was given the machine by Greg Wassmann, a former employee of the legendary Weird Stuff Warehouse, a computer junk shop in Sunnyvale, California, that acts as a clearinghouse for companies all over Silicon Valley. Wassmann also said he has no idea where it came from.

“It was just sitting there on a pallet,” he said. “I’m a Mac nut. I wanted it because it was weird. The owner sold it to me for $5, and I gave it to Bruce for his museum.”

Requests for comment at Apple have not yielded a response. And a number of Mac experts and historians are unable to shed any light on the Black Mac.

“Unfortunately, I don’t know anything about the Black Mac,” said Alex Soojung-Kim Pang, principal author of Making the Macintosh, Stanford University’s history of the Mac.

“I’ve never heard of this Mac and suspect it was a prototype or after-market alteration, because it doesn’t appear in any literature from Apple that I’ve ever seen,” said Owen Linzmayer, author of Apple Confidential, an Apple history. “I was actively covering all things Macintosh during the 1986 to ‘87 time period, and I’m sure I would have remembered this unit had it ever been officially released.”

Dan Knight, publisher of the Low End Mac, was familiar with Tempest-shielded PCs but had never come across a shielded Mac.

Hal Layer, a professor emeritus at San Francisco State University and the owner of the only Tempest-shielded Mac documented on the Net, was also unfamiliar with the 1891 T. Unlike the Black Mac, which was made by Apple, Layer’s TPI-863 was an after-market modification by a company called Techmatics Technologies, which took the guts of a Mac Plus and put them inside an all-metal case.

In addition to the Black Mac, Damer’s DigiBarn will feature a collection of vintage Macs, including one of the first Macs ever shipped, complete with all its shipping materials and documentation. He also has an Apple II GS “Woz Edition”—the last of the Apple IIs, specially designed by Apple co-founder Steve Wozniak and adorned with his nickname.

Damer popped the lid to reveal the GS’ motherboard. “It’s a classic Woz design,” Damer explained. “Few chips. Lots of slots. Open.”

He gestured to the original Macintosh, the brainchild of Steve Jobs, sitting on a bench nearby. “The Mac is from the same time but is the total opposite,” he said. “Jobs closed it up. You need a special screwdriver to open the case. No slots. Closed and proprietary. There’s the two cultures of Apple right there. One open, one closed.”

Damer will also be displaying a number of Mac oddities, like a Ouija board game called Gypsy by Magnum Software.

Instead of using an upturned wine glass, everyone gathers around and puts their fingers on the computer’s mouse. The letters of the Ouija board are displayed on the computer’s screen. “It combines the illogic of the spirit world with the logic of computers,” said Damer. “It’s a great idea for a game.”

Damer also has a prototype telepathy trainer made by San Francisco philanthropist and inventor Henry Daiken. The electronic game has lights that flash on and off that are supposed to be controlled by your mind.

The pride of Damer’s collection is a Cray 1A Supercomputer, a giant, multimillion-dollar dinosaur from the Cold War used to simulate nuclear weapons. These days, its computing power is roughly equivalent to a 300-MHz Pentium PC.

The DigiBarn will also showcase about 3,000 nerdy T-shirts donated by Taylor Barcroft, who collected them over the course of attending a decade’s worth of trade shows. It will also feature a lot of original documents, like the first issue of Byte magazine.

Damer hopes to get most of his machines operating with original software so that people can relive the early days of computing.

“Every time you bring a nerd to the computer museum, their faces light up with memories,” said Galen Brandt, Damer’s partner. “You see grown men crying when they see some of these systems.”

source: wired news

Tag: A Top-Secret, One-of-a-Kind Mac