The first versions ran on a saturn processor the same as the HP-71B.
The orignal Voyagers (11C, 12C, etc) used a _NUT_ processor, similar to
the one in an HP41. According to the datasheet there are differences
mostly relating to the different battery voltage.
Original 11Cs and 12Cs contained 2 chips. The smaller one is the Nut CPU.
The larage one is the ROM/RAM/Display Driver, always known as 'R2D2'.
16Cs are much the same, the 15C has a thrid chip which is extra memory.
Rik, I looked at your photos... It looks like some 9000/300 machines are
going to be of interest to me. Darn, something else to look for :-). And
I love your vehicle :-)
-tony