Monolithic Memories Incorporated 5701/6701 bit slice processor

The Monolithic Memories Incorporated 5701/6701 bit slice processor family was introduced in 1974. This 4-bit processor could be used to build microprocessor systems of any word length in multiples of 4 - 4-bit, 8-bit, 12-bit, and so on. The processor had 16 4-bit accumulators, one scratch accumulator, and came with 352 on-chip ROM, that was used to store instructions' microcode. Standard instruction set included 36 arithmetic and logic instructions, but, if desired, MMI could produce custom-order chips with client-specific instructions in the ROM. Processor instructions were complex, i.e. they could perform multiple operations at once - one arithmetic or logic instruction, and one or more of the following actions: load register, shift left or right, and store result. The 5701/6701 was capable of executing one instruction per cycle.

The 5701/6701 family consisted from two members: 6701 is a bit-slice processor operating in commercial temperature range, and 5701 is a BSP operating in military temperature range. Both types of processors were manufactured in 40-pin ceramic DIP package.