Computermuseum: Munix on Cadmus

Status: public -- Last revision: February 24, 1997

Cadmus (Heinz)

The Cadmus was one of the first commercially available Unix machines. Cadmus was developed by PCS (Perifäre Computer Systemen Munich).

The name of the OS was Munix (Münich Unix).

The hardware was a processor board based on the MC68020 processor with a Q-bus interface. The Q-bus was the bus used in a number of PDP's from Digital Equipment. A large number of devices were available for the Q-bus. To use this devices on the Cadmus only a new driver had to be written. The Q-bus had a address limit of 256 Kbytes, therefore a separate bus with an addressreach of 16 Mbytes was used between the processor- and memory boards.

The Cadmus was our first machine with a bitmap addressable display. At that time standards like X-windows were not yet available and the display could only be used through a special library. Therfore this display has never been a large success.

The department did buy a Cadmus to run the Pascal version of Lila. But the Pascal compiler had problems with large programs and Lila did never run on the Cadmus.

The Belgian distributor of Cadmus had delivered a PDP board with four serial lines. They did however forget to switch off the special interrupt generated by this board to get the PDP in debug mode when a user entered a break. When this happened the Cadmus did crash with a panic. We had to fill in a "Absturzprotokol" (remark the German orrigin). After about a year the distributor did find the solution, but at that moment the enthousiasm for the Cadmus was strongly decreased.

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