Below is the board for the PFC Ap1000 , it control the yoke , rudder, throttle etc. I want to hook it up to simvim without completely rewiring everything (X-plane does not support Serial/rs232 devices ). i noticed the circuit design is basically the same as simvim except the Max231. it uses the sn74ls165n,sn74ls191n,sn74ls145n etc instead of CD74HC4067 as multiplexers . it also used tlc545ifn as ADC.
My question is can i just tap signal from the existing address bus(probably before the max231 chip) or i have to do everything from scratch.
Your system use the decoders, counters and shift registers to convert inputs into its specific serial protocol using Max231 (serial line transmitter/receiver) for serial link. Of course you cannot use it as-is with any other system that has completely different data exchange protocol.All you can do - remove this board, and connect all control elements directly. Escpecially if it's just a few potentiometers and butons - you can do this in few minutes using SImVim.Vlad