[aus.computers.ibm-pc] Printer Query - BIOS/DOS 3.3

pcampb@rhea.trl.oz.au (Peter Campbell) (07/20/90)

This is a repost - we have been having problems with the news machine
here - apologies to those who may have already received this.


Hello, all.  Here at the Research Labs we are having a problem with
MS-DOS printer timeouts, and I was wondering if anyone out there could
help us.

We are using MS-DOS 3.3 and have a program written in Turbo-C V2.0 that
needs to know whether a printer is connected to a computer - either
directly attached or redirected through a network.  We are using the
BIOS calls provided in Turbo-C/DOS-BIOS to check whether the printer is
connected.  This works perfectly when a printer is connected, but not
when this isn't the case.

When there aren't any printers connected to the machine it will wait for
a BIOS timeout.  However, we have found that this isn't a fixed time -
we are getting timeouts anywhere between 5 seconds and 55, with a few
machines hanging rather than timing out.

We would like to somehow use the DOS calls to test the printer, so a
different version is not needed when different DOS BIOSs are used.  We
would also like to be able to set the timeout time to a fixed amount.
The Technical Reference manual makes reference to a specific byte that
is used for the BIOS printer timeout time, and the DOS call also uses a byte
somewhere, but the manual doesn't say whether these are the same bytes -
and knowing DOS, they probably aren't.

Hence, would anyone know of a DOS call/routine that:
	(1) Works on all DOS Versions (or at least V3.x+)
	(2) Checks for redirected printers (e.g. across networks)
	(3) Allows a fixed printer timeout to be set.

Please E-mail responses  - a code example would be nice if anyone has one.
If there is enough interest I'll summarise and send it out to the
newsgroups.

Thanks in advance.

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Peter K. Campbell                      | Phone :
2/M6                                   | Aust. :    03 541 6751
Telecom Research Laboratories          | Int.  : + 613 541 6751
P.O. Box 249                           | Fax   : + 613 543 6026
Clayton 3168                           | Email : p.campbell@trl.OZ.AU
Victoria, Australia                    |
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