The Commodore 900

Also known as the "Z-Machine" for its processor, the Commodore 900 was another foray into business computing that never left port. Classified as a mainframe computer, the 900 runs a flavor of UNIX called "Coherant" in order to lend it the multi-tasking, multi-user capabilities it needs for this market.

According to other reports, the Commodore 900 (also called the Z-8000 on early design materials), came in two varieties: a server and a workstation. The workstation has the high video capabilities lacking in the server, which was heftier in memory and disk space. Although labeled "Workstation", my server has a seperate unidentified daughterboard (?), the server text video port, and the numerous RS232 ports for networking with Workstations. Unlabeled, my workstation has the high-power video port, and fewer RS232 ports.

The documentation I have on Coherant is extensive. It describes a fully functional UNIX OS with a complete "emacs", grep, awk, as, ed, and many other features.

Statistics, features, and CBM 900 resources:

Here is a view of the ports of my server. From left to right, they are: RS232C, RS232C, Text video, (next row): Parallel Printer, RS232C, RS232C, IEEE-488. On the front is the keyboard port.

Here is a view of the ports of my workstation. From left to right, they are: Unknown (RGBI?), Hi-res video, (next row): Parallel Printer, RS232C, RS232C, IEEE-488. On the front is the keyboard port.

Personal Note:These machines were acquired through lucky internet happenstance. A wonderful German fellow named Claus Schoenleber had TWO of these beauties, and was willing to part with them! God bless him! Unfortunately, this machine, like all the other German CBM-II machines I own, will not power up. It's definitely the power supplies fault, but I do not understand it.