I recently had the pleasure to visit Prof. Dr. Bernd Ulmann, leading Guru of Analog computing, an avid collector of aged computing devices and electronics paraphernalia. I had an older HP Spectrum analyser which I wanted to donate and I was invited to see the beautiful collection of analog computers.
Unlike the recent devices that all of us use, an analog computer does not execute algorithms in a step-by step fashion but uses precise analog circuits that are wired to solve the problem in question. Interestingly, for many kinds of problems this approach is more suitable than digital, sequential processing. Calculations happen in real time by definition and parameters can be varied by the turn of a potentiometer, lending a tactile element to IT. One area of interest is the simulation of dynamic processes such as the control of a self propelled projectile or the suspension of a car. In fact, the A4 rocket was controlled by an analog computer called the “Mischgerät”.
Pictured below is a RA770 computer by Telefunken
There are some youtube videos detailing the systems operation:
Bernd also owns plenty of more recent digital computers, such as the lovely HP9820 (aka Model 20) on which I learned programming.
In case you are interested in these areas, check out his websites at:
I can definitely confirm, the man has the knack! It’s time to get him into ham radio.