I have recently downloaded the freeware Bendix King FMC and 'installed' it into my B737-800 aircraft panel.
I have loaded a flight plan and then programmed the FMC according to the first 2 or 3 pages of the document which came with the FMC gauge as follows
I set the 'Performance' information (cruise altitude) pressed the Calc Vnav (RK6) then EXEC to calculate altitudes at each waypoint and then hit the ACTVATE to turn on Vnav output to the Autopilot.
I then take off and after climbing to around 2000 feet engage the autopilot in the panel however ONLY the IAS is set (to 250). The altitude is NOT set. Also if click on the NAV button in the panel the aircraft does NOT turn to the correct heading for the first waypoint, it simply flies on the same heading.
Any ideas what I am doing wrong.
Lastly should the NAV/GPS switch be set to NAV or GPS? It defaults to NAV. If I change it to GPS the aircraft turns to the correct heading HOWEVER this would be because the GPS has also been auto programmed by the 'load flight plan' right?



