SCO Unixware Release 7.1.4  
          SCO Unixware Release 7.1.3 with the latest Maintenance. 
          SCO OpenServer Release 6.0.0 
          SCO OpenServer Release 5.0.7 

          How do I change my printing subsystem between CUPS and SYSV
          and what issues might I expect to find with USB printing?

          For OpenServer 6.0.0 and OpenServer 5.0.7 based systems changing 
          your default print system can be done in one of three ways:

          * on a system-wide basis in /etc/default/lpd. The default entry is
            for the SYSV print system:

            PRINT_SYSTEM=SYSV 

            To use CUPS as the default change to:

            PRINT_SYSTEM=CUPS

          * on a per-login basis by including PRINT_SYSTEM=CUPS or
            PRINT_SYSTEM=SYSV in the environment.

          * by including --sysv or --cups as the first argument in the
            print command line (example: lpstat --sysv -t). 


          For UnixWare7 systems:
         
          The `chprnsys` command can be used to determine your 
          current configuration, as well as switch between CUPS and 
          SYSV(lp) print subsystems. The system default subsystem is SYSV.
           
          `chprnsys` without any options, will report your current 
          configuration.  
           
          `chprnsys cups` will switch to the cups print subsystem. 
           
          `chprnsys lp` will switch to the SYSV print subsystem.

           
          CUPS supports more types of printing, including USB 
          printers. If you are using a USB printer then you'll need to
          restart cups before you can use the printer:

             /etc/init.d/cups restart
           

          When switching between print subsystems, any existing 
          printers will need to be redefined in the new print 
          subsystem as there isn't any mechanism to migrate the 
          printer definitions between the two. 
           
          CUPS support was first added to 7.1.3 in Update Pack 3

          You can't have both CUPS and SYSV printing methods enabled 
          at the same time on UnxiWare 7 systems.

          USB Printing is explained more in http://www.sco.com/ta/126706 but is
          relevant for OpenServer5/6 and UnixWare7:

-----
When defining the printer, use the USB device name. When a USB printer is connected 
to the system and turned on, two device nodes are created automatically for the 
printer. They can be listed by entering:

ls -tr /dev/usb_prnt* /dev/usblp*

The device node names are defined as follows:

/dev/usb_prnt# 

The # appearing in the device name is the order the printer was recognized as 
attached. If you have only one printer, it will always be at /dev/usb_prnt0 
regardless of how it is physically connected. If you have multiple USB printers 
connected (which is not currently supported), the digits at the end should not be 
regarded as stable: they will change as, for example, device timing varies and 
configuration changes are made.

Please Note: Only device names of the form /dev/usb_prnt# should be used in the 
scoadmin printer LP manager. See the procedures referenced above for how to add 
printers to LP and CUPS.

/dev/usblp-#####-[###.###.###.###.###.]### 

The first five digit number is the location of the host controller interface (HCI) to 
which the printer is connected. It's five digits represent the PCI bus number (two 
digits), the PCI device number (two digits), and the PCI function number (the final 
digit). For example:

/dev/usblp-00072-1.4.2 

The above device name indicates that the HCI is located at PCI bus number 00, PCI 
device 07, PCI function 2. Note that this number is completely determined by the 
hardware vendor's PCI configuration.

The remainder of the device name after the second dash is a sequence of from one to 
six decimal numbers, each of which can be from one to three digits. The final number, 
which is required, indicates the port number on the device to which the printer is 
physically connected. Up to five hubs can be connected between the printer and the PC 
USB port, and the ports to which these devices are connected are indicated by the 
five optional three digit numbers in the device name, separated by periods.

For example, if a USB printer were connected directly to the first USB port on the 
system, the device name might look like this:

/dev/usblp-00072-1

A device name like /dev/usblp-00072-1.4.2 indicates the following device 
configuration:


PC USB Port 1 --- | Hub#1 Port 1
PC USB Port 2     | Hub#1 Port 2
                  | Hub#1 Port 3
                  | Hub#1 Port 4  --- | Hub#2 Port 1
                  ...                 | Hub#2 Port 2  --- USB Printer
                                      ...

where Hub#1 is connected into the system's first USB port, a second hub is plugged 
into Hub#1 Port 4, and the USB Printer is plugged into Hub#2 Port 2. This device name 
is completely unique and will not change as long as the physical configuration of the 
USB devices is not changed.
-----

When configuring a printer in "scoadmin printer" for SYSV or CUPS as
the Device:

/dev/usblp-00072-1

For OpenServer5: You will see /dev/usb/lp.0010111.1 for example as an option in
"scoadmin printer" SYSV and CUPS Device listing.

For OpenServer6 and UnixWare7 you would need to specify the Device manually 
within "scoadmin printer" SYSV configuration.

As a simple test before you run "scoadmin printer" you can run:

# usbprobe

to determine if the device is connected.

The print directly to the port with:

For OpenServer5:

# echo "hello world" > /dev/udi/usb_prnt0

For OpenServer6/UnixWare7:

# echo "hello world" > /dev/usb_prnt0

If this locks up then there is a communication issue between the server and the
printer.

If this returns but no print comes out then it's likely the operating system 
does not support printing to your particular USB printer.

       http://osr600doc.sco.com/en/PR_gimpprint/x456.html

Caution Regarding USB Printers 

CUPS versions 1.1.11 and later REQUIRE the user to insure that the desired USB 
printer is powered on AND physically connected to the USB bus BEFORE starting the 
CUPS software. 

CUPS must see the USB printer when the software starts. The CUPS software is 
typically started when the computer boots. Note that one cannot simply plug in the 
USB printer and power it on after CUPS has started. (Note that this does not apply to 
parallel port printers). 

If the USB printer was not connected and powered on at the time CUPS was started, 
there will not be a USB printer shown in the list of devices on the CUPS Admin Device 
Window (see Figure 3-4). In this event, stop the CUPS software, properly connect and 
power on the USB printer, and restart the CUPS software. 

From the list of devices shown in the CUPS Admin Device Window (see Figure 3-4), a 
clever user might attempt to avoid this issue by selecting Internet Printing Protocol 
and then enter something similar to 'usb:/dev/usblp0' in the next screen. However, 
this fails later in the configuration process with a "client_error_not_possible" 
error message with no other explanation. Note that entering 'file:/dev/usblp0' will 
not work either. While CUPS will allow this, printing will not actually work in some 
situations. 

CUPS versions 1.1.10 and earlier exhibit similar behavior with regard to not 
displaying the USB printer if it was not connected to the USB bus and powered up 
prior to starting the CUPS software. However, these versions of CUPS will indeed 
allow the user to enter the name of the USB connection, unlike versions 1.1.11 and 
later. 
 

          

 chprnsys(8) 
 http://uw714doc.sco.com/cgi-bin/man?mansearchword=chprnsys&mansection=8 
 http://uw714doc.sco.com/en/Navpages/PRhome.html
 http://www.cups.org/documentation.php