Thanks for your/and others invaluable help in guiding me along.

The faulty analog inputs an8, an9 and an12 when connected to a pot 0-5v would, when the applied voltage was reduced, indicate the correct voltage until the voltage went down to 1.5v. I then connected a milliamp meter in circuit with the analog input and measured a current of 1.6 ma. After reading the sbc44 manual I now believe these inputs cannot be used as analog inputs but can be used as digital i/o? I do however have 10 analog inputs that work correctly, as I shall be using lm35/ad22100 to measure temperatures, hopefully.

PS I have now succeeded in getting pc vb2005 to usb pic4550 and believe I now understand how it works. Does upgrading to vb2008 express give any problems?

Tom