One of the first computers on the west coast, the SWAC, built in 1950, had a 4-bit op code (https://en.wikipedia.org/wiki/SWAC_(computer) https://en.wikipedia.o

One of the first computers on the west coast, the SWAC, built in 1950, had a 4-bit op code (https://en.wikipedia.org/wiki/SWAC_(computer) https://en.wikipedia.org/wiki/SWAC_(computer)). For a year, it was the fastest computer in the world. I enjoyed programming it in the early 60's. I even wrote an assembler for it that ran on the 1401. It had a 36-bit word - 4-bit op code and 4 8-bit addresses. It had 256 words of Williams tube memory. It took up a whole room.