In 1950s, computers used transistors. The operation times went down from miliseconds to microseconds. To maximize processor utilization, specialized hardware was introduced to handle input and output operations. The computers were running a simple operating system, responsible for loading other programs from punch cards or paper tapes and executing them in batches.
| Hardware | Year | Software |
|---|---|---|
| Transistor - a semiconductor device capable of amplifying or switching an electric current has been invented by William Shockley at Bell Laboratories. | 1947 | |
| IBM 701 - a computer developed by IBM, uses vacuum tubes, multiplication and division operations take 500 microseconds. The first computer that was mass produced (as far as 19 computers can be considered a mass :-). | 1952 | |
| IBM 350 - a harddrive developed by IBM, capacity of 5 MB at 50 rotating magnetic discs with a diameter of 61 cm. | 1956 | |
| IBM 709 - a computer developed by IBM, uses vacuum tubes, multiplication and division operations take 240 microseconds. | 1957 | Fortran - a programming language developed by John W. Backus at IBM. |
| IBM 7090 - a computer developed by IBM, uses transistors, a multiplication operation takes 25 microseconds, a division operation takes 30 microseconds. | 1958 |
One of the most powerful computers of the time was IBM 7094. The computer could perform floating point operations in tens of microseconds and was equipped with 32k words of memory, one word being 36 bits. Specialized hardware provided channels for independent input and output operations that could interrupt the processor.
The IBM 7094 computer run the Fortran Monitor System (FMS), an operating system that executed sequential batches of programs. A program was simply loaded into memory, linked together with arithmetic and input and output libraries and executed. Except for being limited by an execution timeout, the program was in full control of the computer.
Executing sequential batches of programs turned out to be inflexible. At MIT, the first experiments with sharing the computer by multiple programs were made in 1958 and published in 1959. Eventually, a system that can interrupt an executing program, execute another program and then resume the originally interrupted program, was developed. The system was called Compatible Time Sharing System (CTSS) and required a hardware modification of the IBM 7094 computer.