Not all EE's have the same education with regard to how semiconductors function. When I was in school I took a class in semiconductor physics - an entire semester on how the wee beasties function - more than most EEs. The prof., Henry Guckel, told an interesting story about an advanced IBM computer he did some work on (not sure if it was the ACS or one of the 9x models). The clock ran really fast, and they were had all kinds of problems with propagation delays - for which their typical cure was to add delay lines - to the point where it slowed down the machine so much that they actually had to back off the clock some. He also didn't like computer programmers very much. Another related story: a pre-requisite for the class was a modern physics class - which was horribly taught, by a prof. the physics department. During the 2nd class or so, Prof. Guckel noticed a lot of "deer in headlights" looks, and stopped. After commenting that the material should have been largely review, he asked when and from whom we had taken the modern physics class - and 3/4 of the class had taken the class from the same prof. during the previous 12 months. After realizing that class had been a disaster, Prof. Guckel spent the next 4 lectures re-teaching most of that entire-semester class - and doing a really good job of it - preparing his own notes and everything, before proceeding through the rest of the class. Really tough course. On 7/13/2015 6:18 AM, Tor Arntsen wrote: