Hitachi announced in 1970 software for the HITAC-1, a full-featured billing machine that was a precursor to the office computer. In 1973 Hitachi announced software for the HITAC 5, a billing machine based on magnetic cards, and software for the HITAC 55 office computer.
In 1977 Hitachi announced L-320/PS, the operating system for the HITAC L-320, a general-purpose intelligent system with such functions as data entry, billing, and remote job inputs. L-320/PS was designed to satisfy the following needs.
- Improve the efficiency of user programming and system operations
- Provide better usability so that even inexperienced operators could quickly learn the system
- Enable the computer to be used both as a standalone offline office computer and as a general-purpose intelligent terminal when connected to a telecommunications line
Hitachi announced two operating systems in 1983. MIOS7 was the operating system for the HITAC L-70 series of office computers that were designed to be fully featured systems with a wide range of hardware scalability, such as selecting the number of connected workstations. MIOS3 was the operating system for the HITAC L-30 and 50 series of dialog-based office computers.
MIOS7/ES was announced in 1986 as the operating system for the HITAC L-70/8 series of office computers. The HITAC L-70/8 series was envisioned as an office processor supplying office automation functions not on a local office basis but as part of an integrated corporate information processing system that encompassed individual-user levels, department levels, and corporate levels. The operating system assumed the following application configurations.
- Multilevel usage of core information
- Information exchanges over a network system
- Information sharing between departments
The MIOS7/AS operating system for the HITAC L-700 series of office computers was announced in 1990. At a time when office processor applications were expanding in the direction of strategic information processing through multilevel access to information, this operating system supported network processes that fused together centralized processes and distributed processes. In addition to dialog-based transactions, these combination network processes included vertical distribution of processes through connectivity with large-scale host computers and horizontal distribution of processes that could handle distributed business tasks.
In 1993 Hitachi announced the MIOS7/AS2 operating system for the elles 7 series of office computers. This operating system was designed in response to increasingly stringent demands on software development to keep pace with the rapidly changing corporate landscape, such as shorter development turnaround times, more orders for high-quality, low-cost development, and reductions of ballooning maintenance costs for existing systems．