Mostek

Early products

Mostek's first contract was from Burroughs, a $400 contract for circuit design. Initially Mostek products were manufactured in Worcester, Massachusetts in cooperation with Sprague Electric, however by 1974 most of its manufacturing was done at their headquarters in Carrollton, Texas. The first design to be produced was the MK1001, a simple barrel shifter chip made using an aluminium-gate PMOS process. This was followed by a 1K DRAM, the MK4006, designed by Vern McKinney, that was manufactured in their Carrollton facility.

Mostek had been working with Sprague Electric to develop the ion implantation process which provided much better control of doping profiles, especially in lowering enhancement-mode transistor threshold voltage and providing depletion-load transistors. Using ion implantation, Mostek became an early leader in MOS manufacturing technology, while their competition was still mostly using the older bipolar technology. The resulting increased speed and lower cost of the MK4006 memory chip made it the runaway favorite to IBM and other mainframe and minicomputer manufacturers (cf. BUNCH, Digital Equipment Corporation).

In 1970 Busicom, a Japanese adding machine manufacturer, approached Intel and Mostek with a proposal to introduce a new electronic calculator line. Intel responded first, providing them with the Intel 4004, which they used in a line of desktop calculators. Mostek's device took longer to develop but was the world's first single chip calculator, the MK6010, used for the Busicom LE-120A which went on the market in 1971 and was the smallest calculator available for some time. Hewlett-Packard also contracted with Mostek for design and production of chips for their HP-35 and HP-45 calculators.

Mostek's product line included telephone tone and pulse dialers, touchtone decoders, counters, top-octave generators (used by Hammond, Baldwin, and others), CODECs, watch circuits, and a host of custom products for a variety of customers. The products used the simple aluminium-gate PMOS (& later aluminium-gate CMOS) process and helped maintain Mostek's cash flow through intense DRAM competition, and other semiconductor market pressures. In 1975 a smoky fire in the wafer fab closed it for several months and production of some critical products was shifted to a friendly fab (Synertek) in Silicon Valley.