what was called cross telling. They handed me this thing and said, 'You're going to define how the hand-over process works between direction centers', [...] and I had no idea what they were talking about. But we had [...] one-kilobit lines connecting the direction centers and I thought, 'Good God! 1,000 bits a second. Well, we'll surely be able to figure out something to do with that. — Saverah Warenstein, former programmer at Lincoln Laboratory, IBM 1952 The first magnetic core memory, from the IBM 405 Alphabetical Accounting Machine, is tested successfully in April 1952. (The image shows 10 × 12 cores; presumably one of 8) "Teaming up with a more experienced engineer, [Mike Haynes] built a core memory with just enough capacity to store all the information in an IBM punch card: 960 bits in an 80 × 12 array. In May 1952 it was successfully tested as a data buffer between a Type 405 alphabetical accounting machine and a Type 517 summary punch. This first functional test of a ferrite core memory was made in the same month that a four-times smaller 16 × 16-bit ferrite core array was successfully tested at MIT." The IBM 701, a binary-addressed computer containing 72 Williams tubes of 1024 bits each, is released in April. Principles of Operation Type 701 does not use prefixes with lengths of words or size of storage. For example, it specifies that memory tubes hold 2048 words each. The IBM 737 optional magnetic core storage stores 4,096 36-bit words. Each plane stored 64 × 64 = 4,096 bits. 1955 The IBM 704 (a binary machine) manual uses decimal arithmetic for powers of two, without prefixes "Magnetic core storage units are available with capacities of either 4,096 or 32,768 core storage registers; or two magnetic core storage units, each with a capacity of 4,096 core storage registers, may be used. Thus, magnetic core storage units are available to give the calculator a capacity of 4,096, 8,192, or 32,768 core storage registers." "Each drum has a storage capacity of 2048 words." 1956 The IBM 702 (a decimally addressed machine) Preliminary Manual of Information uses decimal arithmetic for powers of ten, without prefixes. "Electrostatic memory is the principal storage medium within the machine. It consists of cathode ray tubes which can store up to 10,000 characters of information in the form of electrostatic charges .... Additional storage, as required, may