The computer used on the Apollo 11 mission was a digital computer. This means that it processed information in discrete form as strings of 0s and 1s.[27] This is distinct from analog computers, which were in more common use at the time and which processed information in continuous form by modeling it on the continuous quantities of various physical processes.[28] Some of its basic specs are that it used 15-bit word lengths, plus one more bit for parity;[2] that it had 32 kilowords or core rope memory and 2 more kilowords of erasable magnetic core memory;[1][2][3] and that it had 16,800 transistors.[1]