Commands for sending TTL Voltages out of serial port?

[Beginner711]

In MAX, (or labview) I would like to send a TTL logic voltage to a
pin.  I want to put 5 volts on a pin and be able to toggle it on
and off with commands.  Also, is there a way to find out which
serial port pin is the ground?

thanks,

shawn

[Beginner711]

Dennis,

When I toggle the pins high and low with the parallel port vi that I
got from the tutorial link you give, the pins go from roughly 0 volts
to .26 volts, which isn't exactly TTL logic levels.  At least not
for the high value.  I have grounded pins 11 and 12 as it says in
the tutorial.

Should I be able to get a proper "high" voltage of above 2.3 volts for TTL logic?

Curious if I've done something wrong.

thanks!

shawn