parallel port input

[Leh Woon Mok]

Brandon,

Thanks much for the clarification.

After trying out more systematically across computers, I have discovered
that the parallel port device on EPrime seems to work properly (i.e., being
able to read from all 5 input pins) only when the computer supports the
newer SPP mode but not when the computer is only to support the older AT
mode.

Under the AT mode, only 2 pins can be read and when the device is connected
through the parallel port key, three pins can be read but the fourth pin
consistently cannot be read.

May I verify my findings with you that it is an issue of whether it's the
AT or the SPP mode?

In addition, there seems to be an interaction with DELL computers.  Across
DELL computers that support either the AT or SPP mode, the parallel port
device consistently does not work well with EPrime, i.e., only 2 pins can
be read.  Under the SPP mode with other computer brands, the parallel port
device consistently works fine.

Hope to hear from you again.

Thanks,
Leh Woon

At 12:47 PM 10/5/2004 -0700, Brandon Cernicky wrote:
>Leh,
>
>By default, E-Prime is directed to work best when a
>parallel port is in standard mode (also known as AT or
>Output only).  This allows for 8 output bits on the
>DATA register (pins 2-9) and 5 input bits on the
>STATUS register (pins 10-13, 15).
>
>First, make sure that the external device is
>connecting to one of the ground pins (18-25) and that
>the device is using a true TTL signal to set the 1/0
>states.
>
>It is possible that on the machines where you are
>having trouble, the parallel port mode is configured
>for the newer Bi-Directional, ECP, or EPP modes where
>the pins control different behaviors.  You can
>determine what the parallel port mode is and configure
>it through the system BIOS.
>
>Although the parallel port hardware key is designed to
>be a pass-through device, you may find difficulty in
>getting communications to work when connecting devices
>to the hardware key.  I would encourage you to
>temporarily not use the parallel key while debugging
>to ensure proper communications.  PST does offer a USB
>version of the hardware key.
>
>If you continue to have troubles, you may want to
>contact PST web support and ask them for a set of
>script routines they have that can configure the
>parallel port to work in Bi-Directional mode, which
>would allow you to read and write to the DATA register
>and have all eight bits of input and output (but not
>at the exact same time of course).  Going through the
>DATA register also allows for no bits being inverted.
>The pre-canned script does all of the technical work
>and all that is needed in the experiment is an InLine
>with "ConfigurePortForRead" call to setup the port.
>
>-Brandon
>
>~~~~~~~~~~~~~~~~~~~~~~~~
>Brandon S. Cernicky
>Senior Software Engineer
>Psychology Software Tools
>
> > Hi all,
> >
> > I'm trying to collect input from an external device
>connected through the
> > parallel port via pins 15, 13, 12 and 10.
> >
> > I have defined my port device as below:
> > address: 889
> > size: 8
> > invert: No
> > mask: -1
> >
> > This worked on some computers but on some computers,
>I can only read from
> > pins 15 and 10 which gave me the hexadecimal outputs
>of 4 and 7, respectively.
> >
> > Strangely enough, on those computers that can only
>read from pins 15 and
> > 10, when the parallel port device is connected
>through the EPrime parallel
> > key (for single licenses), pin 12 worked as well,
>but I still can't read
> > from pin 13.
> >
> > I hope someone could provide me with some insights
>as to what is happening.
> >
> > Thanks much!
> >
> > Regards,
> > Leh Woon
>
>
>
>
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