"Steve Foley" wrote

You are correct. The correct procedure is to use a Sinclair ZX-81, enter the
program, and save it to tape. If you'll notice, this uses the same 1/8" jack
as the line-in or music-in on your intercom.

If you don't have a newer intercom, you'll need to enter the commands four
bits at a time using the Fuel Pump, Nav lights, landing light, rotating
beacon switches. ( see http://home.att.net/~n6480r/IMG_1340.JPG )

When you have the correct arrangements of switches, depress the starter
button.

NO! Don't do that. That is the back door way to fire the ejection seat!
--
Jim in NC