Thanks so much for your time and effort helping me out. Much apreciated.
Clear as mud??? Not too bad actually.
My software arrived and I've moved to a PIC16F818 to retain the 10bit ADC and the ability to run at 20MHz. The PIC's are in the post so hopefully this weekend i can complie a test program and see if i can get a psi reading into the serial port on my PC.
From there on, I have to figure out how to write code for a 3 digit 7 seg multiplexed display.

I was wondering if i could run the code you provided first, stored the value, and used it as an offset calibration for altitude. Then apply it to the same code again, run in the main part of the program to give a true altitude adjust reading. Obviously you want 0 psi displayed at 10,000 feet just like you would at sea level. I dont know by how much atmospheric pressure changes at different altitudes. Nothing a search wont turn up.

Once again, thanks for the wonderful help and advice.


James.