Lost computers: the Commodore 900 wanted to change the world thanks to Unix, but the Amiga made it irrelevant

The Commodore 64 sold like hotcakes, but the company’s engineers knew that the age of 8-bit computers had an expiration date. In 1983 three of them came together to create a 16-bit computer that could succeed in the business market, and that project ended up crystallizing in the Commodore 900.

This model, unknown to many, was especially surprising due to the use of an operating system called Coherent, an interesting clone of UNIX systems. Neither its 16-bit architecture nor that operating system were of much use: Commodore’s other great project, the Amiga, ended up devastating and leaving the Commodore 900 in oblivion.

Unix was fine, but AmigaOS was very much AmigaOS

The computer of course It was very different from the Amiga who ended up being the absolute focus from Commodore, and this despite the fact that its design is clearly reminiscent of the Amiga 2000 box, although it had slight differences in its dimensions and of course in its ports.

The Commodore 900 consisted, for example, of a 5.25 “disk drive – the Amiga opted for 3.5” floppy disks -, and was based on a very rare 10 MHz Zilog Z8001 processor (nothing from the Motorola 68000 of the Amiga) accompanied by 512 KB of RAM and a 20 MB hard drive.

The idea was to turn the C900 – also known as the Z-8000 or Z-Machine – into a viable alternative to PET / CBM machines they had had some success in the business market in Europe.

Manufacturing was expected to start in 1985 in Germany, but only 50 prototypes were made which were sold as development machines before the project was canceled.

In addition to its processor, the team’s surprise it was probably your Coherent OS, a somewhat limited UNIX clone (it did not have a TCP / IP stack for example) that allowed us to enjoy the power of the command console but which was also possible to take advantage of in the field of graphics.

An user you have now gathered all the information found available on the Commodore 900 at this website dedicated to retrocomputing. There we found diagrams of the computer or manuals for Coherent, but also the roadmap of a project that finally did not come to fruition.

The fact that the Amiga 1000, the first of that legendary family, was much more powerful and versatile. Not only for its hardware and dedicated chips, but also for its operating system, an AmigaOS that was a milestone for things like its preemptive multitasking.

It didn’t help that Commodore had to make a big bet: had no capacity to mass-produce the C900 and the Amiga 1000 at the same time, and ended up betting on the last one. In view of the events and the success of the Amiga, they were right.

Still what happened to the C900 is a shame. Commodore’s proposal with this machine was singular, especially in one of the two versions that appeared, a workstation with 1024 x 800 pixel graphics support (on a monochrome monitor, though), something unheard of for the time.

Via | VintageComputer.ca

More information | Datamuseum.dk