The BINAC was a bit-serial binary computer with a 512-word acoustic mercury delay line memory divided into 16 channels each holding 32 words (31-bit) with an additional 11-bit space between words to allow for circuit delays in switching. The clock rate was 4.25 MHz which yielded a word time of about 10 microseconds.
New programs or data had to be entered manually in octal using an eight-key keypad.