I know alot about microcontrollers/microprocessors. 8 bit does not describe the instruction set. 8 bits is the amount of bits the process can process per single cycle. It can have 10 bit resolution because it would then be split into 2 8 bits data. H/L pair. I know a whole lot about them. I know how to wire them, program them, hook it up to the ISA/PCI slot inside the computer.

FMS will tell you how many channels your tx is transmitting because it reads the source code (PPM) directly from the TX before it is modulated to 72mhz and transmitted via air.

Also the PIC doesn't use all 8 i/o as A/D converters. Those that are hooked up to the toggle switches are just used as digital i/o (1/0). They toggle what the PIC should do. Ie channel reverse 1=normal/0=reverse etc. Or they can be used to set flight mode and cause sub routine 2 to be ran instread of 1 etc.

Also now days, CCPM mixing is done on the TX. If you hooked up a ccpm tx to fms, you would then notice that as you increase the throttle/pitch 3 channels would response because ccpm requires 3 channels. Same if you applied elevator/aileron either 2 or 3 channels will change.

The nice thing about FMS is it decodes the single source stream into 8 distinct channels. If you setup FMS right and only notice 4 channels, it only transmitts 4 channels.