HITAC (HItachi Transistor Automatic Compute

is the designation for the majority of Hitachi large and midrange computer models spanning several decades. The HITAC 301, released in May 1958, was Hitachi's first fully

transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...

ized computer model. Earlier Hitachi computers made use of semiconductors known as

parametron Parametron is a logic circuit element invented by Eiichi Goto in 1954.Information Processing Society of Japan Parametron/ref> The parametron is essentially a resonant circuit with a nonlinear reactive element which oscillates at half the driving ...

Beginnings

Hitachi Ltd. (now referred to as Hitachi), first began research in

analog computer An analog computer or analogue computer is a type of computer that uses the continuous variation aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities (''analog signals'') to model the problem being solved. In ...

s in 1951 with

digital Computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These program ...

s following in 1956. As a prototype for the

logic circuit, the HIPAC-MK-1 was developed. The main transmission lines designed by Tadami power development utilized these as tensiometers. It was then that as Parametron calculators, the HIPAC 101 and HIPAC 103 became commercialized products. Parallel research in

computers soon became commercialized as well. ;HIPAC MK-1（1957） :38 bit-words. fixed-point number. 1024 words of

Drum memory Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory. For many early computers, drum memory formed the main working memory of ...

. ;HIPAC 101（1960） :42 bit-words. fixed-point number. 2048 words of Drum memory. In Paris, 1959, Automath was exhibited. ;HIPAC 103（1961） :48 bit-words. fixed/ floating-point. 1024/4096 words of

Magnetic-core memory Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, core. Core memory uses toroids (rings) of a hard magneti ...

. (8192 words of Drum memory). As a base, the ETL Mark IV

ized computer model was introduced and was the first commercialized in 1959. The Japan Electronics and Information Technology Industries Association produced this model intended for business use. In the following year, the HITAC 501 was released and now supplies the Eastern Osaka

Kansai Electric , also known as , is an electric utility with its operational area of Kansai region, Japan (including the Keihanshin megalopolis). The Kansai region is Japan's second-largest industrial area, and in normal times, its most nuclear-reliant. Befo ...

substation as a control system.　Additionally, the Electric Testing Lab still accepts orders for the ETL Mark V. Using this as a base, researchers at the University of Kyoto cooperated to improve the technology which resulted in the HITAC 102 (also referred to as the Kyoto-Daigaku Digital Computer 1). Researchers at Japan's Economic Planning Agency introduced an improved version (HITAC 102B) as a substitute to the punch card system. In 1961, the HITAC 201 was developed as a smaller computer for business use. ;HITAC 301（1959） : BCD12 fixed decimal point expression. 1960 words of Drum memory. (High speed access of 60 words is possible) ;HITAC 501（1960） :First computer as a control system （Insufficient Details） ;HITAC 102（1960） :ETL Mark V prototype ;HITAC 201 （1961） :BCD11 fixed decimal point expression. 4000 words of Drum memory. Moreover, in 1958, The

Railway Technical Research Institute , or , is the technical research company under the Japan Railways group of companies. Overview RTRI was established in its current form in 1986 just before Japanese National Railways (JNR) was privatised and split into separate JR group compani ...

of Japan dispatched

MARS Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

. Although the first version of MARS did not include the HITAC system, its successor MARS101 utilized the HITAC 3030. After that point, Hitachi consistently used it as its mainframe. Hitachi {{compu-hardware-stub