Rahul Sharma (Editor)

ATandT Unix PC

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Type  Professional Computer
Operating system  AT&T Unix v3.51
Release date  1985 (1985)
AT&T Unix PC
Manufacturer  Convergent Technologies
Media  5¼-inch floppy disks, optional quarter-inch cartridge tapes
CPU  Motorola MC68010 with custom Memory management unit clocked at 10Mhz

The 3B1 (also known as the PC7300, or Unix PC) was a Unix workstation computer originally developed by Convergent Technologies (later acquired by Unisys), and marketed by AT&T in the mid- to late-1980s. Despite the name, the 3B1 had little in common with AT&T's other 3B-series computers.


Hardware configuration

  • 10 MHz Motorola MC68010 (16 bit external bus, 32 bit internal) with custom, discrete MMU
  • Internal MFM hard drive, originally 5 MB, later models with up to 67 MB
  • At least 512K RAM on main board, expandable via expansion cards
  • 3 expansion slots
  • Monochrome green phosphor 10-inch (250 mm) monitor
  • Internal 300/1200 bit/s modem
  • PC7300

    The initial PC7300 model offered a very limited 512 KB of memory and an extremely slow 5 MB hard drive. This model, although progressive in offering a Unix system for desktop office operation, was painfully slow and had an aggravating 'grinding' noise even when not in active use. The modern-looking "wedge" design was innovative, and in fact the machine gained notoriety appearing in many movies as the token "computer."

    AT&T 3B1

    A later enhanced model was renamed "3B1". The cover was redesigned to accommodate a full-height 67 MB hard drive. This cover change added a 'hump' to the case, expanded onboard memory to 1 or 2 MB, as well as added a better power supply.

    Operating system

    The operating system is based on Unix System V Release 2, with extensions from 4.1 and 4.2 BSD, System V Release 3 and Convergent Technologies. The last release was 3.51.

    Programming languages

  • LPI Pascal (programming language)
  • LPI C (programming language)
  • SVS Pascal
  • GNU C++
  • LISP
  • Application software

  • SMART System (Office Suite)
  • Informix (DBM)
  • Oracle (DBM)
  • Multiplan (Spreadsheet)
  • Word processors

  • Microsoft Word
  • AT&T Word Processor
  • Crystalwriter
  • WordStar 2000
  • Samna Word
  • WordMarc
  • SMART Word Processor
  • Games

  • Pac-Man
  • NetHack
  • Chess
  • Klondike
  • Life
  • Mahjongg
  • Moria
  • Robots
  • Rocks
  • Rogue
  • Tetris
  • Utility

  • HoneyDanBer UUCP package.
  • Various Shells: Bourne, C, and Korn
  • Kermit
  • TeX
  • SPICE/NUTMEG (circuit simulation tool)
  • The Store

    The Store is a public domain software repository which was available for all 3B1 users.

    Expansion Cards

  • DOS-73 8086 co-processor card running MS-DOS, which could be fitted with an 8087 math co-processor chip. This board was designed and built for AT&T by Alloy Computer Products of Framingham MA.
  • RAM card could be added using 1 or 2 MB RAM cards (up to a maximum of 4 MB)
  • EIA/RAM combo cards contained extra RAM and two RS-232 serial ports.
  • Dual EIA port card
  • StarLAN 1Mbit/s LAN card
  • Ethernet 10 Mbit/s LAN card
  • VoicePower card allowed for the capture and digital recording of voice conversations.
  • Tape drive card provided interface for 23 MB MFM Tape Cartridge Drive.
  • Expansion chassis card was hard-wired to Expansion Chassis (with five added slots)
  • Networking

  • StarLAN – 1 MB/s local area network typically used in star format.
  • References

    AT&T Unix PC Wikipedia

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