The 1400-series machines stored information in magnetic cores as variable-length character strings separated on the left by a special bit, called a "wordmark," and on the right by a "record mark."

Input and output support included punched card, magnetic tape, and high-speed line printers.

The IBM 1460 is logically, but not physically, identical to a 1401 with all of the options, with 16,000 characters of memory, and twice as fast.

The 1400 stores alphameric characters internally in binary-coded decimal (BCD) form, spanning six bits called BA8421.

Arithmetic is 10-based with the one's position at the high- and the most-significant decimal digit at the low-address end of a multi-digit field, thus of ″big-endian″ style.