IMP-16

It consisted of five PMOS integrated circuits: four identical RALU chips, short for register and ALU, providing the data path, and one CROM, Control and ROM, providing control sequencing and microcode storage.

The IMP-16 is a bit-slice processor; each RALU chip provides a 4-bit slice of the register and arithmetic that work in parallel to produce a 16-bit word length.

[1][2] Each RALU chip stores its own 4 bits of the program counter, several registers, the ALU, a 16-word LIFO stack, and status flags.

The chipset was driven by a two-phase 715 kHz non-overlapping clock that had a +5 to -12 voltage swing.

[4][5] The IMP-16 was later superseded by the PACE and INS8900 single-chip 16-bit microprocessors, which had a similar architecture but were not binary compatible.