Ken Shirriff writes:
Intel’s first product was not a processor, but a memory chip: the 31011 RAM chip, released in April 1969. This chip held just 64 bits of data (equivalent to 8 letters or 16 digits) and had the steep price tag of $99.50.2 The chip’s capacity was way too small to replace core memory, the dominant storage technology at the time, which stored bits in tiny magnetized ferrite cores. However, the 3101 performed at high speed due to its special Schottky transistors, making it useful in minicomputers where CPU registers required fast storage. The overthrow of core memory would require a different technology—MOS DRAM chips—and the 3101 remained in use in the 1980s.3
This article looks inside the 3101 chip and explains how it works. I received two 3101 chips from Evan Wasserman and used a microscope to take photos of the tiny silicon die inside.4 Around the outside of the die, sixteen black bond wires connect pads on the die to the chip’s external pins. The die itself consists of silicon circuitry connected by a metal layer on top, which appears golden in the photo. The thick metal lines through the middle of the chip power the chip.
See the full post and more details at Ken Shirriff’s blog.