Dalton Computer
I have been reading this thread with some amusement as I used the IIId-6B Dalton computer as an essential tool during my RAF navigational training sixty years ago. The oldest a/c was a Wellington T10 and the concept of flying to an accuracy of half a degree would have caused a good deal of mirth. It was a device which matched, in accuracy, the aircraft and the compasses which we used at the time - the DRC, distant reading compass - was temparamental, the gyros worked on alternate Thursdays when there was an R in the month and the autopillot had a disconcerting habit of losing 1,000 feet when switched in.
The IIID was very good, I could calculate a DR ahead, new track, course, ground speed and revised ETA in about 3 minutes after getting a fix.