Meanwhile….

Lately, We have traced back the history of integrated circuits to a few very early devices, primarily manufactured by RCA and examples of ‘MOS’ type ICs. The metal-oxide-semiconductor geometry was the final design revolution, leading directly to modern chips. However, there were (and still are, unlike RCA) other manufacturers. Here’s a Raytheon RC1033 3-input NOR circuit:

The circuit logic is fairly easy to follow. Around the same time (1966), Motorola was producing the MC832P, a 4-input NAND gate:

later (1969!), Motorola was making the 3000L quad 2-input NAND gate:

and 3005L, a triple three-input NAND gate array:

Yet another company, Fairchild Semiconductor, introduced a radically different kind of circuit- the operational amplifier. Here are images of the μA709, Fairchild’s breakthrough product:

the LM710:

μA741:

and μA741 made by AMD the next year (1972):

Lastly, here’s one we have yet to identify, part code U5B771239:

If you know what this is, let us know!

The Fairchild cicuits look radically different than the others- there’s no obvious symmetry to the layout, as opposed to the previous examples.