Multibus

[1] The Multibus specification was a robust industry standard with a relatively large form factor, allowing complex devices to be designed on it.

Because it was well-defined and well-documented, a Multibus-compatible industry grew around it, with many companies making card cages and enclosures for it.

Sun built custom-designed CPU, memory, SCSI, and video display boards, and then added 3Com Ethernet networking boards, Xylogics SMD disk controllers, Ciprico Tapemaster 1/2 inch tape controllers, Sky Floating Point Processor, and Systech 16-port Terminal Interfaces in order to configure the system as a workstation or a file server.

Companies like Northwest Technical still provide "End of Life" products for Multibus I, which is now considered obsolete.

The Automatic Train Supervision elements use a mixture of iRMX on Multibus, and Solaris on SPARC computers.

The safety-critical Automatic Train Protection component is provided by trackside and trainborne equipment that does not use Multibus.

In the control centre, Westinghouse also provided a cut-down mimic of the system for staff training and software test purposes using much of the same hardware and software as the full ATS system, but connected to a computer (also Multibus-II and Sun based) to simulate train movements and signaling behavior.