Ken Shirriff, a researcher specializing in computer history and reverse engineering, came across this unique chip while investigating the internals of an old HP computer.

Turns out it’s a pretty familiar chip

Contrary to expectations, the chip was not part of a state-of-the-art design; It was located on a modest floppy drive controller circuit board, located between the HP interface bus (HP-IB) and the Z80 processor. Its main function was to manage data transfer and buffering protocols.

A transparent microcircuit made with technology “silicon on sapphire”It may seem cutting-edge, but the method has been in use since at least 1963, Shirriff noted.

Features of the mysterious chip

Shirriff shed light on the distinctive features of such chips by highlighting the effectiveness of the sapphire substrate as an insulator separating different areas of silicon. He says this design “improves performance by reducing leakage between transistors.”

In addition, sapphire’s insulating properties make it a shield against stray currents, protecting against short circuits and radiation; This is an extremely important feature in space electronics.

Despite the technological prospects of the transparent chip, Shirriff noted its strangeness as “an interesting example of future technology that has not yet fully proven itself.” While these chips showed superior performance compared to their traditional silicon counterparts, HP’s silicon-sapphire-based chips had a very low performance of 9%.

The researcher suggested that these transparent chips could potentially define the course of the technology if mass produced with higher performance and lower cost.