This was a small computer which used ICs throughout for processing units. It was announced in December 1965. The operating system was a disk oriented system developed independently by Hitachi. It allowed two types of job processing: batch processing (which was already widely used) as well as inline processing. In inline processing, the creation of various bills and updating of related files is done using software called a "POP system". This machine enabled high-speed arithmetic processing by using CML-based ICs throughout as basic circuits for processing units. Two types of main memory unit were available -- 4 kilobyte and 8 kilobyte -- and cycle time was 1.5 µs. For disk units, the system used a double-sided 0.7 megabyte replaceable disk cartridge, and a maximum of two of these units could be connected. Performance of the line printer was 150/300 lines/minute (110/63 different characters), but to reduce costs, Hitachi adopted a system of reducing the printing hammers by half, and printing by shuttling paper to the left and right. This computer was the first system from Hitachi to have a role as a smaller model of a mainframe, and a role as an office computer -- by enabling easy processing of routine office work using a POP system.