Intel 4004

           <<<    >>>    ^^^

In the beginning the copyright for the microprocessor i4004 belonged to the customer, the japanese "Busicom". Later, when this company ran in financial troubles, Intel bought it back for $55.000 with one restriction: The chipset was not allowed to be used in desktop- or pocket-calculators. But this kind of programmable logic had many applications like this controller of Telxon.

The processor itself is very small it has only 16 pins. With the 6-time multiplexed bus the wiring was very simple. 12 of the 16 pins could be directly to the 4002 RAM and the 4001 ROM. The remaining 4 pins served as I/O-ports. Later, when static memories like 1702-EROMs came up, intel developped the 4289, a demultiplexer. It has 40 pins, much more than the 4004 CPU.