Each lunar mission had two 16-bit Raytheon Apollo Guidance Computers (AGC) comprised of 32 kilowords (equivalent to 64kB) of ROM and 4 kilowords (8kB) of RAM, one in the Command Module and another in the Lunar Module as Guidance, Navigation and Control Systems.
The Lunar Module also had an 18-bit TRW Abort Guidance System (AGS) - ROM 2 kilowords (4.5kB) & RAM 2 kilowords (4.5kB) - as a backup to its AGC. The AGS could be used to take off from the Moon, and to rendezvous with the Command Module, but not for landing.
The Saturn V used for orbit insertion had a 28-bit IBM Launch Vehicle Digital Computer (LVDC) with 32 kilowords (112kB) of memory.
http://en.wikipedia.org/wiki/Apollo_Guidance_C omputer