Please read this: The Main Controller controls all operations in the recorder. The Operating System, pSOS+, is resident in an EPROM on the Main Controller.
Operating System
pSOS+ is a real time multitasking system that dows priority tasking. For instmce, Video
data is assigned a higher priority than Graphic Data, so video data is processed fist. pS0S+
uses the filesystem pHile, similar to UNXX. At Power on, the Main Controller loads pSOS+
From the EPROM and the recorder data from the floppy disk into the RAM on the Main
Controller and executes instructions as required. The recorder is then initialized.