Connecting
an MS-Dos Application to a Printer on a USB Port
on Windows 2000
by Curtis Krauskopf
DataFlex, an MS-Dos application, was written in an era when the only printer
ports were serial ports and parallel ports.
A USB port is a completely foreign concept to character
mode DataFlex. From
DataFlex's point of view, printing to a USB port is
as odd as trying to print to the status lights on the
keyboard. The DataFlex character mode runtime was never
designed to write to a USB port called USB001:.
Despite that, and because of Windows 2000's flexibility,
DataFlex and most other MS-Dos applications can be coaxed
into printing character mode documents to a USB printer..
The solution is to assign the USB-connected printer
a network name, and then to associate that network name
with an unused LPT port. The DataFlex program will print
to the LPT port and Windows will automatically redirect
the job to the USB printer port.
The first step is to install the USB printer normally
into Windows. The easiest installation is when Windows
2000 automatically recognizes the printer. This
typically happens when you're using a name-brand
printer or when the printer had previously been
installed on the computer.
In most situations, you need to be logged in as
an administrator, or as a user with administrator
security privileges.
2.
Print the Test Page
Once the printer is installed and the obligatory
test pages print correctly, proceed to the following
steps.
Find the share name for the computer. Share
names are also called network names or
resource names. On Windows 2000, computers
are assigned network names even if they aren't attached
to a network. Your computer's network name might
have been assigned by the computer manufacturer,
or maybe by your IT department, or it might have
been assigned when you originally installed Windows
2000. Substitute your computer's resource name with
computer_name in these
instructions.
Find out the printer's share name (also called
resource name or network name). Generally, the name
is assigned during printer installation and it might
have been assigned automatically. Just like resource
(network) names for computers, printers can be assigned
share names even if you're not attached to a network.
In these instructions, substitute
printer_name for the share name assigned
to your printer.
Share names can contain letters, digits and a few
special characters, like spaces (blanks). Even though
share names can contain spaces, I recommend not
putting spaces in resource names. The reason is
because it's more difficult to use operating system
commands when spaces exist in the resource name.
Figure 1 shows an example of an operating system
command that will not work because the resource
name (in this example, a computer cleverly named
"my computer name") contains blanks.
net view \\my
computer name
Figure 1: This command will not
work because spaces are in the computer
name.
If the network administrator for your system insists
on names with embedded spaces, figure 2 shows a way
to do it.
net view "\\my computer name"
Figure 2: This command will work when
spaces are embedded in a computer name.
As shown in figure 2, double quotes are used to tell
Windows 2000 that the words my computer name
belong together. The double quotes are a single
double-quote character -- not two single quote characters
next to each other. Even though they look nearly
the same on the screen, two single quotes will not
work.
Open an operating system command prompt. The operating
system command in figure 3 assumes that LPT1 is
an unused port. At the operating system prompt,
enter the command shown in figure 3....
net use LPT1 \\computer_name\printer_name /Persistent:Yes
Figure 3: This command defines a persistent
printer connection to LPT1 for a computer
cleverly called computer_name and a printer
called printer_name.
where:
LPT1 is the name
of the unused parallel printer
port. Note that a colon (:) does not
appear after the port name on the command line.
\\computer_name
is the resource name of the computer that is
attached to the USB printer.
\printer_name is
the resource name (share name) of the USB printer
discovered in step 4.
/Persistent:Yes
denotes that this connection should be reestablished
when the system is rebooted. There must not
be a space after the slash and after the colon.
If the command line above is wrapping to two lines
then widen your browser's window because the above
command is on one line.
Figure 4 shows an example of using the command
in Figure 3. In Figure 4, the computer
is named Dell and the printer is named HP. Figure
4 more clearly shows the spaces between the command's
parameters.
net use LPT1 \\Dell\HP /Persistent:Yes
Figure 4: This example shows how to use the command in Figure 3.
Figure 5 is another example of the command in
Figure 3, but blanks (spaces) are inside the resource
names. In figure 5, the computer's resource name
is "Dell Computer" and the printer's name is "HP
Printer". HP
ink cartridges are an optional accessory.
net use LPT1 "\\Dell
Computer\HP Printer" /Persistent:Yes
Figure 5: When one or both of the resource
names contain blanks
(spaces), surround the entire resource name
with double quote characters (") to tell
the operating system that the words belong
together.
A note about /Persistent:Yes:
The /Persistent:Yes
parameter will tell Windows 2000 to reestablish
the connection when the system is rebooted.
If the printer is not connected to the computer
when it boots, Windows 2000 will usually remember
the connection anyway. Depending on your system's
defaults and security settings, Windows 2000
might even ask if you want to have the printer
connection deleted when Windows 2000 can't find
the printer anymore.
However, the operating system is not perfect
at remembering that you specified /Persistent:Yes.
I have seen situations where Windows 2000 seemed
to spontaneously decide that the printer connection
wouldn't be defined after a reboot even though
the printer was connected to the computer and
powered on. When that happens, the only way
to reestablish the connection is to follow the
above instructions. You can
to help you remember how to reestablish the
printer connection.
The command in figure 3 can be inserted into the
autoexec.bat or network login script, whichever
is most appropriate for your installation. If you
do that, eliminate the /Persistent:Yes
parameter because you're making the connection persistent
by using the autoexec.bat or network login script.
7.
Optional: Verify the connection
The command in figure 6 shows how to verify that
the connection was successful. Enter the command at
the operating system prompt.
net view \\computer_name
Figure 6: Verify that the connection
was successful.
The following screenshot shows the successful
use of these commands.
In the net use command, the
Used as column shows that the
hpphotos printer has been assigned to LPT1.
8.
Test the printer
The commands in figure 7 show a way to test that
the printer has been successfully configured.
The ^L part of the command means:
press and hold the control key and tap the
L key
release the control key
Enter the commands at an operating
system prompt. Press the Enter key at the
end of each line.
dir > lpt1:
echo ^L > lpt1:
Figure 7: Test the printer connection
by sending data to it.
The strange incantation in figure 7 sends a directory
listing to the printer. The last page (it might
be the only page) of the printout should eject
from the printer after you type the ^L key combination.
Many thanks to alert reader Eric Meyer for passing
along the tip for easily ejecting a partial page.
Depending on your printer's configuration and
settings, the first page might automatically eject
after the 'dir' command and a
blank page will eject after the 'echo'
command.
If you get an error message similar to this one
after using the dir > lpt1:
command:
then verify that the printer is turned on and
that all of the cables are securely connected
to both the printer and the computer.
If nothing printed on the printer and you didn't
get a Windows error message box even though you
typed the commands exactly as they appear in figure
7, then see the next section, Optional printer
configuration.
9.
Optional printer configuration
For DataFlex and other MS-Dos programs, the data
stream for the printer port might need to be changed
from RAW to Text mode. Symptoms of when you need
to do this are:
Nothing is printed after a directory listing
or when the MS-Dos program printed something
to the printer.
The printer is printing meaningless and useless
information on the pages, such as squiggles,
lines and random characters.
Only part of the printout is printed by the
printer.
To fix these problems, start by opening the printer
configuration panel:
Start
Settings
Control Panel
Printers
Right Click on the Printer to display its
context menu
Choose Properties from the context menu
Change the data stream from RAW to Text mode. Use
these steps:
Choose the Advanced tab or button
Choose the Print Processor button
In the Data Type section, change the data
type from RAW to TEXT.
Apply and Close the printer panel.
Try the test in Figure 7 again. In all of the
Windows 2000 installations I tried, I was always
able to get successful results.
Deleting the USB Connection
The command in figure 8 shows how to delete the LPT
port connection.
From
DataFlex's point of view, printing to a USB port is
as odd as trying to print to the status lights on the
keyboard. The DataFlex character mode runtime was never
designed to write to a USB port called USB001:.
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