An example of early integrated circuits, these flat-pak ICs were made by Sperry Semiconductor, a division of Sperry Rand Corporation (UNIVAC). They have a datecode of 6546 - 46th week of 1965.

Note the alternative expression "MicroNet", from the days before "integrated circuit" was universally agreed upon. In the same era, Texas Instruments was calling their ICs "Semiconductor Networks", from which the "SN" prefix of TI part numbers stems.

An examination of the die under a microscope indicates these are a very simple RTL-class, dual 2-input inverting gate, also configurable as a single 4-input inverting gate. It is almost identical to the Fairchild RTµL 914, but in a flat-pak rather than TO-99 package. The 1M4 has 580Ω load resistors rather than 640Ω, and has separate V+ connections for the two load resistors or gates rather than a common V+, making the 1M4 a little more flexible.

• Schematic (PDF)