Timeline of Binary Prefixes - 1950s

1950s

• In the 1950s, "1 kilobit" meant "1000 bits":
  • "In the '50s, amazingly enough—and only total coincidence—I actually was given the job of writing the operational specifications They handed me this thing and said, "You're going to define how the hand-over process works between direction centers," and—and I had no idea what they were talking about. But we had... uh... 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

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, built a core memory with just enough capacity to store all the information in an IBM punched 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 does not seem to use "kilobit" anywhere. Specifies that memory tubes (IBM 706) hold 1024 bits each, drum memories (IBM 731) hold 2048 words each.
  • The IBM 737 optional magnetic core storage stores 4,096 words. Each plane stored 16×16 = 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

February

• The IBM 702 (a decimal 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 be provided through the use of magnetic drum storage units, each having a capacity of 60,000 characters."
  • "A character may be a letter of the alphabet, a decimal number, or any of eleven different punctuation marks or symbols used in report printing."
  • "Each one of the 10,000 positions of memory is numbered from 0000 to 9999 and each stored character must occupy one of these positions." (page 8)

July

• The word byte, meaning eight bits, is coined by Dr. Werner Buchholz in July 1956, during the early design phase for the IBM Stretch computer.
• IBM 650 RAMAC (a decimal addressed machine) announcement
  • "The 650 RAMAC combines the IBM 650 Magnetic Drum Data Processing Machine with a series of disk memory units which are capable of storing a total of 24-million digits. The 305 RAMAC is an entirely new machine which contains its own input and output devices and processing unit as well as a built-in 5-million-digit disk memory."

1957

June

• The IBM 705 (a decimal addressed machine) Operating manual uses decimal arithmetic for powers of ten, without prefixes.
  • "A total of 40,000 characters can be stored within the main storage unit of the Type 705."
  • "Each one of the 40,000 positions in memory is numbered from 0000 to 39,999." (page 17)
  • "One or more magnetic drums are available as optional equipment with a capacity of 60,000 characters each."

• Lewis, W.D., Coordinated broadband mobile telephone system
  • Earliest instance of "kilobit" in both IEEE explore and Google Scholar: "Central controls the mobile link with a rate of 20 kilobits per second, or less".

1959

• The term 32k is used in print to refer to a memory size of 32768 (215).
  • Real, P. (September 1959). "A generalized analysis of variance program utilizing binary logic". ACM '59: Preprints of papers presented at the 14th national meeting of the Association for Computing Machinery (ACM Press): pg 78–1–78–5. doi:10.1145/612201.612294. "On a 32k core size 704 computer, approximately 28,000 datum may be analyzed, … without resorting to auxiliary tape storage." The author is with the Westinghouse Electric Corporation.