3b1

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The 3B1 (also known as the PC7300, or Unix PC) was a desktop Unix computer originally developed by Convergent Technologies (later acquired by Unisys), and marketed by AT&T. These machines were loosely referred to as the 'Unix PC', and were initially released in the mid-80's under the moniker 'PC7300'.

1 Hardware Configuration
2 Operating System
3 See also
4 Resources

[edit] Hardware Configuration

10 MHz Motorola 68010 CPU
Internal MFM hard drive, originally 5 MB, later models with up to 67 MB
512K RAM on main board, expandable via expansion boards
3 expansion slots
monochrome green phosphor 10" display

Initial design

The initial versions of the 3b1 offered a very limited 512K of memory and an extremely slow 5 MB hard drive. This version, known as the PC7300, 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'.

The Hump

Later models of the PC7300 took on the more common product-line name '3b1', and gained capability. The cover was redesigned to accommodate full height 67 megabyte hard drives. This cover change added a 'hump' to the case, expanded onboard memory to 1 or 2 megabytes, as well as added a better power supply.

[edit] Operating System

The operating system is based on UNIX System V Release 2, with extensions from BSD 4.1, BSD 4.2, System V Release 3 and Convergent Technologies. The most recent version is 3.51, with a 3.51 m FIXDISK (2.0) available. The FIXDISK was available from AT&T directly.