Part 1a. By this point Microsoft had also supplied the BASIC for Perkin-Elmer's very expensive Model 3600 "intelligent terminal". These were more than just te

Part 1a. By this point Microsoft had also supplied the BASIC for Perkin-Elmer's very expensive Model 3600 "intelligent terminal". These were more than just terminals capable of limited client-side processing for time-sharing systems. As stand alone desktop units they were powerful enough for scientists to acquire data, store it, process it and/or control data-intensive instruments which a year earlier had required a large non-desktop host, often a forklift model. The 3600 was the first desktop to actually resemble an early IBM PC, horizontal unit having two prominent 5 1/2" floppies, and with the detachable keyboard (also introduced softkey F-row) & monitor. Other than that the box was simply a microprocessor & memory with two RS-232 ports (known as serial COM ports ever since later release on IBM PC's), and an external instrument connection, not supposed to be expandable or upgradable internally. ROM bios booted (without a floppy) to a novel Disk-Based Operating System known as the Perkin-Elmer Terminal Operating System (PETOS) where a few of the DOS commands were available from ROM, but the remaining majority of the commands were expected to be present on a floppy residing at DISK0. DISK1 was expected to usually be employed for application program & data storage. These were proprietary Perkin-Elmer programs to interface with their own scientific instruments but many users wanted to develop their own programs in BASIC like you could on the competitive Hewlett-Packard equipment using their built-in HP BASIC. The team that had designed the 3600 had of course been separated into numerous more rewarding projects. Anyway Perkin-Elmer got Microsoft to provide the BASIC for the 3600, and and as we all gained deeper knowledge of PETOS by operating this equipment, it really helped later when the IBM PC was launched because its DOS had such an uncanny similarity.