(Perhaps this is another Trevor Taylor disk.)

It somehow uses the AY-3-8910 to read a light pen input.

None of these programs are usable on the emulator as it doesn't
emulate this periperal device.

Mostly it contains assembly language source code, but there are a few
executables:

TEST2.PRG
    This draw a bunch of binary-sequenced rectangles in order to ID
    exactly where the light pen is pointing.

MENU.BAS  (works in tandem with MENU.PRG)
    experiment -- presents a number of colored boxes; one can be
    selected by pointing the light pen at it.

LPDRAW.PRG
    light pen drawing program