-=> On 05 Aug 95  22:59:00 Leon Deboer said to All <=-

 LD> I am told OS2 virtualizes all of it's IO space and devices and if
 LD> this is true is the following possible on a network connected under
 LD> OS2.
 LD> Can a parallel port on machine A be "virtualized" on machine B so
 LD> that it looks like a local port.
 It can.

 LD> My reason for wanting this in that I
 LD> have some DOS/WINDOZE programs which must obviously use direct LPT
 LD> access on a local basis in that they can not be fooled into printing on
 LD> a network they report only the local ports even though I have other
 LD> "VIRTUAL" ports allocated with network printers.

These presumably don't use the bios to access the printer port, and hit the
hardware direct.

 LD> What's invloved if is possible and any programmers willing to
 LD> discuss a fee to do it?

You have to set up the hardware to interrupt if an attempt is made to
access the port, go and look at the instruction that did it, and pass it
to the other machine. If its an IN, you also have to get the data, then
restart the trapped program. It sounds easy, but it is fiendishly hard
to debug.

The timing is completely screwed. Anthing timing sensetive wont work.
(This means dongles normally, but also parallel to scsi converters,
and parallel port network cards. Some printers have bi-directional comms
using the control lines for data, and these may not work either.)

I might quote, but I'm working at present, and don't have the time.

If you cant find someone else you might try twisting my arm.

Andrew


... Engage brain before operating mouth
--- Blue Wave/Max v2.12 OS/2 [NR]