reading the status bits of parallel port continuously?

[Marlene Richter]

Hello everyone,
    I am new to E-Prime (about 2 weeks) so perhaps someone with more
experience can answer this question. However I did not see it in any of
the manuals, discussions or on the E-Prime website.
    I have been able to successfully use the WritePort command to
trigger an external device (address &H378), and the ReadPort command to
receive a trigger from an external device on the parallel port
(address:&H379) as described on the E-Prime website. For the ReadPort
command, I kept cycling through an "If Then Else, Else loop" until the
4th bit (pin 15) changed its state, and then exited the label loop to
start the main portion of the code (my paradigm).
   However, I would like to continually poll the status pins at address
&H379 to know when changes in state occur throughout the experiment. I
would like to use the first TTL input pulse from an external device to
trigger the main paradigm of the experiment, but I would like to keep
continuing the experiment (without any interruptions) as I record
additional  TTL signals from the external device. For example, if my
external device is putting out 100 TTL pulses, I would like to start the
main portion of my paradigm presentation immediately after the first
pulse, and record all the subsequent 99 pulses and their timing in the
E-DataAid file without disrupting my paradigm timing.
    Can anyone provide me with some help or advice? Will E-Prime even
permit this? Any suggestions would be greatly appreciated.


Thanks for any suggestions you may be able to provide!
P.S. I am still using the Beta 5.0 version.


Marlene Richter
mrichter at princeton.edu