Gunner Asch fired this volley in
:

USB to just about any sort of output..serial, parallel etc etc are
commonly available at any computer shop


Yeah, Gunny, but they're not "real" hardware ports. They don't work in
real-time. They operate through USB drivers to serialize your commands,
then on-board (out on the 'dongle') drivers in flash or rom, both of which
can independently queue operations without your knowlege or permission.
It's often difficult, sometimes impossible, to generate real-time signals
offa USB devices.

LLoyd