Model:PC7300, later 3B1
CPU:Motorola MC68010 @ 10MHz
RAM:512K base
Display:12-inch 80x29 text
 720x348 graphics
Ports:Serial, parallel, 2 telephone
Expansion:Three expansion slots
Storage:Internal 10MB Winchester drive
OS:UNIX System V

In 1985, AT&T Information Systems introduced a product destined to set a new standard for business computers - the AT&T UNIX PC Model 7300, designed and built by Convergent Technologies.

What placed this PC so far out in front? Extraordinary power, exceptional ease of use, unsurpassed communications capabilities, and maximum flexibility.

No other PC offered so much at once. No other PC offered this kind of performance combination.

UNIX Systems V is the key to the power of the AT&T UNIX PC. It allows you to process more data faster.

Its super power lets you take advantage of the multi-tasking talents of UNIX System V. You can perform a number of tasks simultaneously on as many as 12 active windows.

And even a novice can learn to use the AT&T UNIX PC in a matter of hours, thanks to features such as a simplified keyboard, a three button mouse, and help functions.

The modern-looking "wedge" design was innovative, and in fact the machine gained notoriety appearing in many movies as the token "computer".

Like the Zenith Eazy PC, the built-in monitor rotates and swivels, but cannot be removed.

The built-in 1200-baud telephone modem and software, allows the UNIX PC to initiate voice and data connections, and keep records of the numbers and connect-time.

Built into the UNIX PC is Starlan, a '"1-base-5" 1Mbps (megabits/sec) network over twisted-pair wire.

The optional windowing manager operating system with 3-button mouse interface, while not shown here, was very advanced for its day.

The UNIX PC could support 5 additional users on their own terminals. One as-is, four more with add-on serial cards.

The later enhanced model was renamed "3B1", as pictured. The top was redesigned to accommodate a full-height 67MB hard drive, expanded onboard memory to 1 or 2 MB, as well as added a stronger power supply.

Built-in troubleshooting and status LEDs:

  • RED: This is the "User LED". It can be turned on and off with the syslocal(2) call. It is not used by any existing applications.
  • GREEN: This LED toggles every time there is a process context change, and is cleared on the whole second.
  • YELLOW: This is the idle LED. When it is on, there are no processes in the ready to run state.
  • RED: Heart-beat LED. This is toggled on the whole second.

  • Related Links

  • wikipedia
  • InfoWorld (Mar 4, 1985)
  • Infoworld (Apr 15, 1985)
  • WSJ
  • "Starring the Computer"
  • BYTE, via
  • 3B1 FAQ
  • UNIX PC Software Archive
  • AT&T 3B1 Emulator, docs and ROMs

  • Return to the Obsolete Technology Homepage