IBM 700/7000 series

The IBM 700/7000 series was a group of several large computer company IBM. They were offered in the 1950s and early 1960s. The individual making the IBM 700/7000 series computers had different, incompatible architectures.


The IBM 700/7000 series consisted of very different computers. In response to the storing of the data and the instructions, this can be classified as follows.

  • First computer ( 36/18-Bit words): 701 (Defense Calculator )
  • Scientifically (36 -bit words): 704, 709, 7090, 7094, 7040, 7044
  • Commercial (variable length character strings ): 702, 705, 7080
  • 1400 series (variable length character strings ): 7010
  • Super computer (64- bit words): 7030 "Stretch"

The 700 class used vacuum tubes, the 7000 class transistors. The early IBM 701 and IBM 702 still used Williams tubes. In the IBM 7070, the transistorized successor to the IBM 650, it was a Dezimalrechner. These data and addresses are shown in decimal form.


In the early computer time the computers were delivered without software. As operating systems arose, this was problematic in the IBM 700/7000 series. Due to the different architectures programs had to be created multiple times. The System/360 procedure was different in this regard. The System/360 took the best aspects of the architectures of the IBM 700/7000 series, but had only a single architecture.

The first architecture (IBM 701)

The computer is also referred to as a Defense Calculator and was introduced in 1953. The data format was either 36 bits or 18 bits long, only as a fixed-point number. The instructions were 18 bits long, with a total of 32 instructions existed. The main memory consisted of 2,048 respectively 4,096 36-bit words, one character over 6 bit possessed.