Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!gatech!gitpyr!stat!curci
From: curci@stat.uucp (Ray Curci (scri))
Newsgroups: comp.sys.ibm.pc
Subject: Re: Determining if a printer is available
Message-ID: <7730@pyr.gatech.EDU>
Date: 27 Mar 89 13:18:27 GMT
References: <2165@pembina.UUCP>
Sender: news@pyr.gatech.EDU
Reply-To: curci@stat.fsu.edu (Ray Curci (scri))
Organization: Dept. of Statistics, Florida State Univ.
Lines: 17

In article <2165@pembina.UUCP> lake@alberta.UUCP (Robert Lake) writes:
>I am trying to determine if a line printer is attached to my PC.  I am

One method of determining whether you have a printer or not with MS-DOS
is to look at some special memory addresses.  If memory serves me, at absolute
address 0x400 in MS-DOS are 8 words of memory that contain the base addresses
for (4)COM ports and (4)printer ports.  I believe that the Lattice C compiler
has a PEEK function, so use it to examine addresses 0x408 and 0x409.  If both
are zero, then there is no printer port, otherwise those bytes contain the
base address for the printer.  Additionally, I believe there are also some
BIOS services that will give you the same information including information
about some of the control signals (whether your printer is on-line, out-of-paper, etc,.)

Look in the IBM PC or IBM AT technical reference software manuals at the BIOS
routines for the printer device for more details.

curci@stat.fsu.edu