The Atari 2600 Video Computer System has 128 bytes of RAM, and early cartridges had 2K ROM. The cartridge port had 13 address wires, but could only use addresses above $1000, yielding a 4K address space. Asteroids was the first cartridge to use 8K (via bankswitching), and some later carts included 16K of ROM and 128 bytes of extra RAM. Warren Robinett's "Basic Programming" cartridge allowed users to type in and run very small BASIC programs; the cartridge had 4K ROM and no RAM, and used 64 bytes for its own scratchpad, leaving 64 bytes of RAM available for the user. Not enough to do much of anything, but still somewhat cool anyway.