BINAC

BINAC, the Binary Automatic Computer, was an early electronic computer designed for Northrop Aircraft Company by the Eckert-Mauchly Computer Corporation in 1949. Eckert and Mauchly, though they had started the design of EDVAC at the University of Pennsylvania, chose to leave and start Eckert–Mauchly Computer Corporation (EMCC), the first computer company. BINAC was their first product, the first stored-program computer in the US, and the world's first commercial digital computer.

The BINAC was an advanced bit-serial binary computer with two independent CPUs, each with its own 512-word acoustic mercury delay line memory. The CPUs continuously compared results to check for errors caused by hardware failures. It used approximately 700 vacuum tubes. The 512-word acoustic mercury delay line memories were divided into 16 channels each holding 32 words of 31 bits, with an additional 11-bit space between words to allow for circuit delays in switching. The clock rate was 4.25 MHz (1 MHz according to one source) which yielded a word time of about 10 microseconds. The addition time was 800 microseconds and the multiplication time was 1200 microseconds. New programs or data had to be entered manually in octal using an eight-key keypad. BINAC was significant for being able to perform high-speed arithmetic on binary numbers, with no provisions to store characters or decimal digits.

The BINAC ran a test program (consisting of 23 instructions) in March 1949, although it was not fully functional at the time. Here are early test programs that BINAC ran:

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