It was a "Dukes Of Hazzard" game my Dad programmed on out 48k ZX Spectrum in 1983.
He made this game to help familiarise me with the keyboard layout (I was age 3).
Basically it was a cyan screen with a large letter or number in the middle of it & a little orange car on the left.
When I pressed the corresponding key the car would jump over the letter & a tune would play, the same as the General Lee's horn.
He also made a maths game based on "Portland Bill".
It had a lighthouse on the left side of screen & the mainland on the right, with Portland Bill in his rowing boat by the lighthouse & some seagulls in the sky.
Every time I got an sum right Portland Bill would move one step closer to the mainland, & every time I got a sum wrong a seagull would descend one step closer to Portland Bill, eventually stealing his lunch in a box on the end of his boat (Game Over).
It had different difficulty levels & different types of sums, addition, subtraction, multiplication & division.
The first professional game I played was either Hungry Horace [http://en.wikipedia.org/wiki/Harrier_Attack] games.