Does Dev.par support read?

QNX Newsgroups (Archives) qdn.public.qnx4
1

Does Dev.par support reading if the parallel port is bi-directional?

2

No, it doesn’t.

The Dev.par source is available from /usr/free, you can add the
support if you’d like.

Heather


Brown, Richard <brownr@aecl.ca> wrote:

\

Does Dev.par support reading if the parallel port is bi-directional?

3

Heather,

Can you supply more info on where to find the source??
There is no such directory as /usr/free on our systems.

Thanks,

Chris Milette

Heather Johnstone wrote:

No, it doesn’t.

The Dev.par source is available from /usr/free, you can add the
support if you’d like.

Heather

Brown, Richard <> brownr@aecl.ca> > wrote:

Does Dev.par support reading if the parallel port is bi-directional?

4

Never mind, I found the file! I just haven’t spent much time
looking around the qnx site.

Now, as an alternative question to the world…

Has anyone already modified dev.par to support reads??? If so,
would they be willing to share it. I’ve got a device I need to
talk to, and reading from the device is rather important!

I’d appeciate any help.

Chris Milette


Chris Milette wrote:

Heather,

Can you supply more info on where to find the source??
There is no such directory as /usr/free on our systems.

Thanks,

Chris Milette

Heather Johnstone wrote:

No, it doesn’t.

The Dev.par source is available from /usr/free, you can add the
support if you’d like.

Heather

Brown, Richard <> brownr@aecl.ca> > wrote:

Does Dev.par support reading if the parallel port is bi-directional?

5

Previously, Chris Milette wrote in qdn.public.qnx4:

Has anyone already modified dev.par to support reads??? If so,
would they be willing to share it. I’ve got a device I need to
talk to, and reading from the device is rather important!

Just one more time in summary. There is no such thing as a generic
way to read a parallel port. The closest to this would be the
IEEE-1284 spec, but it only describes the transport mechanism,
not how you get the device to provide data. Likewise there are
Host-Host protocols such as lap-link, but these need special cables.


Mitchell Schoenbrun --------- maschoen@pobox.com