In 1978 Heathkit introduced the Heathkit H8 computer. The H8 was very successful, as were the H19 and H29 terminals, and the H89 "All in One" computer. The H8 and H89 ran their custom operating system, HDOS, and the popular CP/M operating system. The H89 contained two Zilog Z80 processors, one for the computer and one for the built-in H-19 terminal. The H11, a low-end DEC PDP-11 16-bit computer, was less successful; probably because it was substantially more expensive than the 8-bit computer line.