Re: [PARPORT] writing data to the parallel port

From: Nordic Boy (jklaas@cs.albany.edu)
Date: Thu May 04 2000 - 08:17:41 EDT

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    Yes, I am finding that out.

    OK, lets talk about strobes for a moment then.

    The IEEE docs say that after the bits are on the line the host sends a low
    pulse on HostClk(nStrobe). (HostClk is some timing function?) I assume
    this is done using something like
    "frob_control(port, PARPORT_CONTROL_STROBE);".

    The peripheral then sets Ptr(nAck) low and PtrBusy(Busy) low. Would we
    then read this using something like "status = read_status(port)" and
    "if (status && (PARPORT_STATUS_ACK | PARPORT_STATUS_BUSY))" after which
    another byte can be sent.

    I noticed that the lp drivers put a delay in. Do you know why?

    James Klaas

    On Thu, 4 May 2000, Philip Blundell wrote:

    > In message <Pine.GSO.4.21.0005031743540.8423-100000@broomstick.cs.albany.edu>,
    > Nordic Boy writes:
    > > {
    > > if( get_user(chunk, buf + curcount))
    > > return -EFAULT;
    > >
    > > mydevice[0]->port->ops->write_data(mydevice[0]->port, chunk);
    > > /* write the data from the user to the port */
    > > curcount ++;
    > > }
    >
    > What port mode are you trying to use here? If it's compatibility mode you
    > will need to provide explicit strobes.
    >
    > p.
    >
    >
    >

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