The IBM System/370 was announced in June 1970 as the replacement for its extremely successful System/360 range of mainframes. It was 100% upward compatible with System/360, running the same operating systems and application programs and supporting the same peripherals, and thus provided an easy migration path for System/360 customers. It replaced the “solid logic” circuitry used in the 360 with monolithic integrated circuits, and the 370/145 and all subsequent models replaced core memory with semiconductor main memory.
When the System/370 was announced, many observers were surprised it did not include virtual memory, which was all the rage in computer architecture at the time, and which IBM had previously introduced in the System/360 model 67 in 1965. In 1972, the original System/370 models 155 and 165 were replaced by the 158 and 168 which did support virtual memory, as did all subsequent models in the series. The System/370 would continue to be marketed for twenty years until replaced by the System/390, with numerous evolutionary changes in the architecture over time.
The IBM 3211 printer shown in the final film was stunning. Nobody made printers like IBM—this beast would crank out 2000 lines per minute, day and night, box after box of paper, without a hiccup.