AMD Am2901 / Am2903 Bitslice
Old-school technology and transfigured inventions.
Before a complete 16-bit or 32-bit CPU could fit on a single silicon die, engineers had to build custom processors by cascading smaller 4-bit ALUs ("slices") and writing their own microcode. The AMD Am2900 family was the absolute industry standard for this era of high-performance, modular computing.
