Decsystem-20

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The DECSYSTEM-20 was a 36-bit Digital Equipment Corporation PDP-10 mainframe computer running the TOPS-20 operating system. PDP-10 computers running the TOPS-10 operating system were labeled DECsystem-10 as a way of differentiating them from the PDP-11. Later on, those systems running TOPS-20 were labeled DECSYSTEM-20. The DECSYSTEM-20 was sometimes called PDP-20, although this designation was never used by DEC. The only significant difference the user could see between a DECsystem-10 and a DECSYSTEM-20 was the operating system and the color of the paint. Most machines sold to run TOPS-10 were painted "Blasi Blue", whereas most TOPS-20 machines were painted "Terracotta".