【Hitachi】 HITAC 20

Announced in 1975, the HITAC 20 was a minicomputer positioned as a high-end version of the HITAC 10II. In terms of architecture, the machine had 16-bit general-purpose registers, and provided 90 instructions by using the microprogram system (32 instructions could be added as an option). In addition to paper tape devices, the system also supported magnetic devices such as floppy disks, and allowed connection to a maximum of 256 devices. Use of a new console display enabled easy correction of source programs. In terms of communication, this machine had a variety of communication controllers (including start-stop synchronous, SYN synchronous and HDLC), and it was widely used as a network controller in applications such as networks between universities. It became possible to input and output mainframe jobs from a remote location by connecting a line printer or card reader using the channel converter for the HITAC M Series of mainframes. This engine was also used as a terminal controller in the second wave of online systems for city banks. The software was PS20, and included control programs and utilities, as well as FORTRAN (JIS7000) and macroassembler as language processors.