The storage-access device

Storage device with random access (RAM) – a kind of computer memory that can achieve at the same time access to any cell by its address on read or write.

IBM 701

IBM 701

The very first computers to carry out the functions of the main memory, the capacity of which was hundreds or thousands of bits used for the delay line memory or relay various vacuum tubes. Built on triodes latch used for higher speed memory blocks (registers, register direct access storage). So, to create a direct access memory chips created a matrix of semiconductor diodes. This situation changed with the appearance of random access memory access (same – a random access unit). Was born about a bit-parallel memory, and in it to the word read from memory and processed by the ALU.

The first computer that used a new type of memory was invented in 1953, is IBM 701. Next – IBM 704, released in 1955, used a ferrite core memory. External devices these computers were slow: IO operation was performed through the ALU. Create a channel input-output ALU allowed to operate independently. The first common type of writable memory direct access storage device was magnetic core, which was developed in the 49-52 years of the 20th century.

In modern computers, the RAM is used to build semiconductor memory devices.