L
Lucvdv
I'm using a custom driver that connects to the parallel port driver
and takes over the port completely, because external hardware is
connected that sends data to the port and requires that it remains in
(bidirectional) input mode 100% of the time.
The port _has_ to have an interrupt vector too, because having to poll
it constantly would eat too much CPU time.
The first tests were done on an AOpen mainboard using W2k and XPe, and
on a Gigabyte with W2k only, and that all worked perfectly, but on the
Gigabyte it only works if the port is in EPP mode. The symptoms seem
to indicate either a timing problem with the ACK signal (out), or a
large delay between the Strobe signal (in) and the actual interrupt.
The problem is with Gigabyte/XPe: I can't use the port in ECP mode
here, and I can't get it to work in EPP mode: with the "ECP Printer
port" component it doesn't recognize the port at all, device manager
lists only the serial ports.
With the "Printer Port" component added the port is there, but
apparently as a standard parallel port only, and I can't get it to
hold the interrupt setting: it always switches back to "never use" by
itself (without even a reboot: just close and re-enter the port
properties in device manager, and the setting is back off again).
[ISTR that the latter is something that can happen in a minlogon
configuration, but this is winlogon]
I've been searching for an EPP component, but that doesn't seem to
exist in XP.
Worst case, and licensing issues put aside, does anyone think it could
work if I created a parallel port component around Win2000's drivers?
There are significant differences in driver structure: in W2k parport
and parclass were two separate drivers, in XP they're one.
I don't think licensing would be an issue: I suppose it's OK to
recompile the sample from the W2k DDK and to use that (if it works).
and takes over the port completely, because external hardware is
connected that sends data to the port and requires that it remains in
(bidirectional) input mode 100% of the time.
The port _has_ to have an interrupt vector too, because having to poll
it constantly would eat too much CPU time.
The first tests were done on an AOpen mainboard using W2k and XPe, and
on a Gigabyte with W2k only, and that all worked perfectly, but on the
Gigabyte it only works if the port is in EPP mode. The symptoms seem
to indicate either a timing problem with the ACK signal (out), or a
large delay between the Strobe signal (in) and the actual interrupt.
The problem is with Gigabyte/XPe: I can't use the port in ECP mode
here, and I can't get it to work in EPP mode: with the "ECP Printer
port" component it doesn't recognize the port at all, device manager
lists only the serial ports.
With the "Printer Port" component added the port is there, but
apparently as a standard parallel port only, and I can't get it to
hold the interrupt setting: it always switches back to "never use" by
itself (without even a reboot: just close and re-enter the port
properties in device manager, and the setting is back off again).
[ISTR that the latter is something that can happen in a minlogon
configuration, but this is winlogon]
I've been searching for an EPP component, but that doesn't seem to
exist in XP.
Worst case, and licensing issues put aside, does anyone think it could
work if I created a parallel port component around Win2000's drivers?
There are significant differences in driver structure: in W2k parport
and parclass were two separate drivers, in XP they're one.
I don't think licensing would be an issue: I suppose it's OK to
recompile the sample from the W2k DDK and to use that (if it works).