What's the rarest or most unusual computer-related item do you own?

Hi Jon, thanks for your email and the positive words... On Wed, 11 Jan 2017, Jon Elson wrote: In all videos the system is completely up and running i.e. cables attached. The platform is only moving in this way if the servo mechanisms are running. The momentum of the gyroscopes is way to small to keep the platform leveled. Interesting is, that the unit spans all aeras of computation: Integration of turn rate is done in the gyroscopes (mechanically, i.e. they are "Rate integrating Gyroscopes"). On the other hand integration of acceleration to velocity is done by the analog computer which also takes care of initial alignment, continuos platform leveling and it also applies various corrections like crosstalk between gyros and accelerometers, temperature compensation, an-isoelastic correction and stuff like this - it contains lots of analog multipliers etc. Last but not leas the digital computer is supervising the analog circuitry, it is taking care of earth rotation, it is calculating position and all other navigation parameters, handles all communication with the external world and it applies an additional correction for gyro drift which it can determine in a 4h long calibration cycle. Erik.