interactive applications. The predecessor to NOS was Kronos which was in common use up until 1975 or so. Due to the strong dependency of developed applications on the particular installation's character set, many installations chose to run the older operating systems rather than convert their applications. Other installations would patch newer versions of the operating system to use the older character set to maintain application compatibility. Cyber 180 series Cyber 180 development began in the Advanced Systems Laboratory, a joint CDC/NCR development venture started in 1973 and located in Escondido, California. The machine family was originally called Integrated Product Line (IPL) and was intended to be a virtual memory replacement for the NCR 6150 and CDC Cyber 70 product lines. The IPL system was also called the Cyber 80 in development documents. The Software Writer's Language (SWL), a high-level Pascal-like language, was developed for the project with the intent that all languages and the operating system (IPLOS) were going to be written in SWL. SWL was later renamed PASCAL-X and eventually became Cybil. The joint venture was abandoned in 1976, with CDC continuing system development and renaming the Cyber 80 as Cyber 180. The first machines of the series were announced in 1982 and the product announcement for the NOS/VE operating system occurred in 1983. As the computing world standardized to an eight-bit byte size, CDC customers started pushing for the Cyber machines to do the same. The result was a new series of systems that could operate in both 60- and 64-bit modes. The 64-bit operating system was called NOS/VE, and supported the virtual memory capabilities of the hardware. The older 60-bit operating systems, NOS and NOS/BE, could run in a special address space for compatibility with the older systems. The true 180-mode machines are microcoded processors that can support both instruction sets simultaneously. Their hardware is completely different from the earlier 6000/70/170 machines. The small 170-mode exchange package was mapped into the much larger 180-mode exchange package; within the 180-mode exchange package, there is a virtual machine identifier (VMID) that determines whether the 8/16/64-bit two's complement 180 instruction set or the 12/60-bit one's complement 170 instruction set is executed. There were three true 180s in the initial lineup, codenamed P1, P2, P3. P2 and P3 were larger water-cooled designs. The P2 was designed in Mississauga, Ontario, by the same team that later designed the smaller P1, and the