The basic unit of the 360 was an 8-bit byte. Some instructions operated on bytes, others on half-words (two bytes), others on words (four bytes), still others on double-words (eight bytes) and byte strings. An instruction or operand always addressed a byte address. It had a 24-bit address field permitting the direct addressing of up to 16mb. However, early 360 models, such as Trader's 360 Model 30, had a maximum of 65K bytes of internal memory, and even the top of the line Model 75 could only have 1mb.

The IBM 360 design assumed an interrupt-driven operating system, that utilized the contents of different control registers in response to an interrupt. It also had a large and varied instruction set, with three types of arithmetic: fixed point, floating point, and a special decimal arithmetic that used strings of 4-bit binary-coded decimal digits as operands. There were privileged instructions that only executed in the supervisor state.

The 2314 was an important new storage device introduced with the S/360. It was a direct access device of eight disk drives that used removable disk packs, of which each pack could hold 28mb of information.

We also had the high-speed IBM-1403 printer, which was capable of 1110 lines per minute. Got those bank statements and reports out damn fast.

The IBM 3420 tape drives were used to store information from the MICR check reader/sorter, which read the information at the bottom of your check (which is printed with special magnetic-type ink) and wrote the info to the tape drive. This is how all those checking accounts were kept updated every day.