Commodore 900
The Commodore 900 (also known as the C900, Z-8000, and Z-Machine) was a prototype microcomputer originally intended for business computing and, later, as an affordable UNIX workstation. It was to replace the aging PET/CBM family of personal computers that had found success in Europe as business machines. The project was initiated in 1983 by Commodore systems engineers Frank Hughes, Robert Russell, and Shiraz Shivji. Manufacturing was to commence in 1985 at Commodore International's West Germany plant, but only fifty prototypes were made and sold as development systems before the project was cancelled.

The C900 was a 16-bit computer based on the segmented version of the Zilog Z8000 CPU. It ran Coherent, a UNIX-like operating system. Two versions of the machine were developed: a workstation with 1024×800 pixels graphics, and a server with text-only display.

The C900's case is similar to the Amiga 2000's but slightly larger.

References

External links
C900 page at 'The Secret Weapons of Commodore' website – By Cameron Kaiser and The Commodore Knowledge Base
This is Z page – By Bo Zimmerman
The Commodore C900 – color photos of a prototype unit
Commodore C900 product announcement
A running CBM900 has survived at datamuseum.dk and several of the ROMs have been reverse-engineered.
Commodore Microcomputer magazine coverage of the 900's announcement
Commodore 900: The Unix-like workstation/server that was eclipsed by Amiga

Comm85
Computer workstations