Travis Blalock Oral History https://www.youtube.com/watch?v=wmqa9XJED-Q https://archive.computerhistory.org/resources/access/text/20...:
"each array element had nearest neighbor connectivity so you would calculate nine correlations, an autocorrelation and eight cross-correlations, with each of your eight nearest neighbors, the diagonals and the perpendicular, and then you could interpolate in correlation space where the best fit was."
"And the reason we did difference squared instead of multiplication is because in the analog domain I could implement a difference-squared circuit with six transistors and so I was like “Okay, six transistors. I can’t do multiplication that cheaply so sold, difference squared, that’s how we’re going to do it.”
"little chip running in the 0.8 micron CMOS could do the equivalent operations per second to 1-1/2 giga operations per second and it was doing this for under 200 milliwatts, nothing you could have approached at that time in the digital domain."
Extra Oral History with inventor of the sensor Gary Gordon: https://www.youtube.com/watch?v=TxxoWhCzIeU