"Informally, the programs were called “ropes” because of the durable form of read-only memory into which they were transformed for flight, which resembled a rope of woven copper wire. For the lunar missions, 36K words of “fixed” (read-only) memory, each word consisting of 15 bits plus a parity bit, were available for the program. In addition there were 2K words of artfully timeshared “erasable” or RAM memory. Allowing for the identical Apollo guidance computer (AGC) in the Command Module (CM), containing a program called COLOSSUS, it is correct to say that we landed on the moon with 152 Kbytes of onboard computer memory."