SCO Merge resource administration
SCO Merge automatically manages access to the most important hardware resources , such as the keyboard, the display, and diskette drives from DOS and Windows sessions.
You must explicitly request (attach) all other devices to use them under DOS or Windows. A device definition describing the particular device characteristics must exist before the device can be attached to your session. The system administrator creates device definitions using the Merge Setup utility in the Desktop environment or command-line utilities from the UNIX prompt. See ``Device definition''.
Several commonly used resources have preconfigured definitions and can be attached to your DOS and Windows sessions. These resources include physical and virtual DOS drives, default printer, COM ports, and a game port. For instructions on attaching these resources, see Chapter 4, ``Configuring DOS and Windows sessions''.
SCO Merge automatically makes the following resources available to all DOS and Windows sessions:
However, when you run SCO Merge outside of the Desktop
(in full-screen mode) or take advantage of the
Desktop's zoom feature, your display adapter
must be completely IBM VGA compatible.
SCO Merge and display modes
On rare occasions, you may want to specify a particular
display mode
for your
DOS environment, for example, if a DOS application functions better in
that mode.
SCO Merge allows you to start your DOS session using VGA, CGA, MDA, or
Hercules display modes.
(Note that you can use Hercules mode only when you are running on the
Desktop.)
See ``Setting DOS display types'' in Chapter 4 for instructions.
Using extended video modes
If you run DOS and Windows sessions in full-screen mode,
your display will be treated as a standard VGA display regardless
of the actual display adapter you are using.
It may also be possible to take advantage of the extended video modes of your VGA adapter and run applications that require resolutions higher than standard VGA (which is 640x480, 16 colors).
To enable DOS and Windows to use extended video modes, you need to create new DOS images using the on-card VGA ROM rather than the standard VGA ROM used by default. See ``Using on-card VGA ROMs'' for instructions.
Using serial terminals
You can use SCO Merge to run DOS from a variety of serial terminals.
Appendix B, ``Using remote terminals'',
discusses the major differences between
terminals and the system console.
Diskette drives
Diskette drives A and B are available to DOS and Windows as long as
neither of them is mounted as a UNIX file system or
otherwise used by the UNIX system (by a cpio process, for example).
SCO Merge automatically
assigns the diskette drives on a first-come-first-served
basis to any DOS or Windows session that attempts to
access them whenever they have been unused for five
seconds or longer.
Drives A and B are assigned and released simultaneously. That is, SCO Merge prevents a DOS or a Windows session from using either diskette drive as long as any other session is using any diskette drive.
A diskette mounted as a UNIX file system
is only accessible through the
UNIX environment and is not accessible as a
DOS diskette drive.
If you insert a diskette
into a diskette drive and mount it
as a UNIX file system, any files on that diskette become
part of the file system shared by DOS and the UNIX
operating system.
You can then
access files on the mounted diskette in the same way
you access files in the fixed disk file system shared by
DOS and UNIX.
The mouse
Any mouse that is properly installed and accessible to the
UNIX system is also accessible to DOS and Windows.
(If you are running a DOS application that uses the mouse on the
Desktop, you have to
focus the mouse first.
See
``Controlling the
SCO Merge window'' in Chapter 1.)
When you use the Multiscreen feature on the console, the mouse automatically communicates with the screen currently displayed.
DOS and Windows sessions always view the mouse as a Microsoft bus mouse. A device driver entry in the system-wide SCO Merge config.sys file supports DOS communication with a mouse. Do not modify this file or a personal config.sys file to specify another mouse driver. In particular, ensure that DOS or Windows applications do not modify any config.sys files to specify another mouse driver when you install them.
By default, the mouse uses interrupt (IRQ) 5, which works for almost all applications. If you discover that your mouse does not work, check the following:
In a non-Desktop environment, follow these steps to change the mouse interrupt:
dos +amousen
win +amousen
Here, n is the interrupt number. (Valid values are 2, 3, 4, or 5; the default is 5.)
mrgconfig dos set mouse=mousen
mrgconfig win set mouse=mousen
SCO Merge provides both Desktop and non-Desktop utilities for you to define and attach devices that your DOS and Windows applications may need. You can also use these utilities to examine, modify, and delete existing device definitions.
Examples of devices for which definitions are required include physical and virtual DOS drives, COM ports, printers, and custom devices such as a modem or scanner.
A device definition provides the information that SCO Merge needs to access a device. Once a device definition has been created, you can use the device by selecting it to be part of a personal DOS or Windows session configuration. This action is called attaching the device for use in a DOS or Windows session. On the Desktop, use the Personal Merge Session Configuration option of the Merge Setup utility to attach devices. Device attachment is described in detail in Chapter 4, ``Configuring DOS and Windows sessions''.
Device definition in the Desktop environment
If you are working in a Desktop environment, use the Device Definition window to display, create, modify, and delete device definitions. Follow these steps to access the Device Definition window:
Use the buttons (Printer, COM1, COM2, DOS Drive, and Custom) across the top of the Device Definition window to select the category of device whose definition you want to view, create, change, or delete.
All device definitions belong to one of the following categories:
A separate view of the Device Definition window exists for each category. For example, if you click on the DOS Drive button at the top of the Device Definition window, you will see all device definition parameters that apply to DOS drives displayed in this window.
There are two versions of the Printer view of the Device Definition window: one for Spooler Attach and one for Direct Attach device definitions. If you click on the Printer button, the view corresponding to the type of printer device currently selected will be displayed.
There are also two versions of the COM1, COM2, and Custom views of the Device Definition window: one for Virtual Attach and one for Direct Attach device definitions. If you click on the COM1, COM2, or Custom button, the view corresponding to the type of device currently selected will be displayed.
The controls that are common to all views of the Device Definition window
are described in ``Token name'',
``Button controls'', and
``Left panel controls''.
Token name
The Token Name box shows the name for the current device definition. A token name is a short name that uniquely identifies a given device.
A token name can contain up to 12 characters consisting of the letters a-z, the digits 0-9, and the hyphen (-). Token names must be unique.
You can use the drop-down list of tokens to select another device definition in the current category. Note that if you modify a device definition, you cannot select another token name or change views until you save the changes (by clicking on the Save or Save As button) or abandon the changes (by clicking on the Undo button or responding to a prompt to discard the changes).
The following button controls appear on all views of the Device Definition window:
After you specify the new token name, you can enter device definition parameters in the fields provided, and then save your definition by clicking on the Save or Save As buttons.
The following controls appear on the left side of all views of the Device Definition window:
On a multi-user system, you should set the Usable By setting to Root while you are developing the definition for a new device to prevent other users from accessing the definition until it is ready for everyone to use. When the device definition is ready for use, change this setting to All to enable all users to select the device for a DOS or Windows configuration.
Note that the specified Failure Action does not apply to Spooler Attach printer definitions.
If you are working in a non-Desktop environment, use the mrgadmin command to display, create, modify, and delete device definitions. See ``Using mrgadmin'' in Chapter 6 for more information.
Physical and virtual DOS drives
A physical DOS drive is a portion of the fixed disk
formatted under DOS and reserved exclusively for
DOS and Windows files.
Your fixed disk may have one or more physical DOS drives of different
sizes.
SCO Merge can access any physical DOS drive on your fixed disk. During installation, and each time you reboot your system, SCO Merge checks for the existence of physical DOS drives and updates its internal database for the drives it finds.
SCO Merge also allows you to create virtual DOS drives. A virtual DOS drive (sometimes called a virtual DOS volume) is actually a UNIX file that has been formatted as a DOS file system and is used to store DOS files. One default virtual DOS drive is provided in each user's home directory.
A DOS drive may be useful with SCO Merge for the following reasons:
If you are working in a Desktop environment, follow these steps to list the available DOS drives:
Tokens for physical DOS partitions are named dosc, dosd, and so on, while the default virtual DOS drive token is named homevdrv.
In a non-Desktop environment, you can use the mrgadmin command to list the available DOS drives as described in ``Using mrgadmin'' in Chapter 6.
To attach an available physical or virtual DOS drive to your DOS or Windows session, use the Personal Merge Session Configuration option of the Merge Setup utility as described in ``Configuring drives'' in Chapter 4.
Creating and formatting physical DOS drives
If you want to have one or more physical DOS drives
on your computer, you should create them before or
at the time you install the UNIX system.
If you do not have a physical DOS drive on your computer and wish to create one, you must back up your fixed disk, create the DOS drive, and reinstall your UNIX system and all applications. For OpenServer systems refer to Chapter 2, ``Installing or upgrading an SCO system'' in the SCO OpenServer Handbook for instructions.
You can also add a second hard disk to your computer and put one or more physical DOS drives on it.
SCO Merge automatically senses these new physical drives the next time you reboot and makes them available by creating device definitions for them. You still need to attach each of the new drives to a SCO Merge drive letter as described in ``Configuring drives'' in Chapter 4.
Virtual DOS drives are different from physical DOS drives in the following ways:
SCO Merge automatically makes the definition for $HOME/vdrive.dsk (token name homevdrv) available. This is the default virtual DOS drive that is located in each user's home directory.
If you are working in a Desktop environment, you can create definitions for new virtual drives as follows:
You can create two types of virtual volumes: One type is for use by all users where the actual volume is shared; the other type is for use by individual users, where each user can have his or her own copy of the defined volume.
Shared volumes are created when you specify the file name using the full UNIX path name. In this case, the actual file should be created at device definition time. Personal volumes are created when you specify the file name relative to the user's home directory. Each user creates actual files for personal volumes at the time of attachment.
Once the new virtual volume has been defined, you can attach it to a drive letter using the Personal Merge Session Configuration option of Merge Setup utility.
In the non-Desktop environment, you can use the mrgadmin and mkvdisk commands to create tokens for new virtual drives as described in ``Using mrgadmin'' in Chapter 6.
Default protection of DOS drives
The UNIX file system protection mechanisms apply in only a
limited way to DOS drives.
Because DOS
drives are not UNIX file systems, access to
individual DOS files in these drives is not
governed by UNIX system user or group ownership
or by UNIX system read, write, or execute permissions.
However, a DOS drive as a whole is accessed as a UNIX file or device and can be protected like any other UNIX file or device.
Here are the considerations that affect access to and administration of DOS drives:
Virtual DOS drives created in public directories have the same permissions
as physical DOS drives, i.e., all users have read and write permissions.
However, by default, only the owner can access personal virtual DOS drives created in
a user's home directory.
The user can relax these permissions
at the time the virtual drive is created.
Changing the protection of DOS drives
If you need to restrict access to a DOS drive, you can use
one or all of the following methods:
When a DOS drive is attached to a DOS or Windows session, SCO Merge does not immediately claim the specified device, but waits until DOS or Windows actually attempts to read or write to the device. Meanwhile, the requested device may become unavailable if another session gets control of it.
To avoid this problem, you can request that the device be attached to DOS and Windows sessions immediately and exclusively. Exclusive access to the specified device means that no other session can attach it at the same time.
Specifying read-only access prevents DOS and Windows sessions from making any changes to the DOS drive.
Using the DOS attrib command to make a DOS file read-only can protect individual files on a DOS volume. The protection offered by the DOS attrib command is limited, however, because anyone who can access a DOS file can also use this command to make the file writeable.
To make a DOS file read-only, use the attrib
command to assign the read-only (R) attribute as follows:
attrib +r filename
When the read-only attribute is assigned, the file cannot be
deleted or changed.
To make the file writable again, type:
attrib -r filename
If you want to restrict access to a DOS drive to specific
groups of users, you can use the UNIX chmod command
to assign any desired
permission mode.
For example,
suppose the UNIX device file name for your physical DOS drive is
/dev/dsk/0s5.
To deny access to users outside the group to which
the DOS drive belongs, you could type:
chmod o-rw /dev/dsk/0s5
To enable a COM port device for use under SCO Merge, you can use the virtual attachment or the direct attachment method. A COM port device configured through virtual attachment is a UNIX serial port that a DOS or Windows process refers to as COM1 or COM2 and accesses through SCO Merge drivers. A COM port device configured through direct attachment is a serial port that DOS or Windows drivers control directly without interfacing with SCO Merge or UNIX.
By default, SCO Merge provides definitions for virtual attachment of COM1 and COM2 to UNIX serial ports named /dev/tty1a and /dev/tty2a on OpenServer syststems, and /dev/tty00t and /dev/tty01t on UnixWare syststems. The tokens that represent these definitions are named com1 and com2 respectively.
SCO Merge also provides definitions for direct attachment of COM1 and COM2. The tokens that represent these definitions are named dcom1 and dcom2 respectively.
In the Desktop environment, the serial ports available to your DOS or Windows environment are listed and can be attached through the Devices view of the Personal Merge Session Configuration window of the Merge Setup utility.
You can also create new COM port device definitions if the standard ones are not adequate.
For example, some cards provide multiple serial ports on a single adapter. Each of these is a separate UNIX device, and UNIX processes can output directly to any of them. DOS and Windows, however, recognize only a limited number of serial ports. In this case, for example, you can create a new virtual COM1 definition, where the physical device accessed is UNIX device /dev/tty4a.
If you are working in a Desktop environment, follow these steps to create a new COM port device definition:
The Device Definition window appears.
You will be able to create a virtual or a direct attached device definition.
For the virtual attach definition, you will need to specify the UNIX device name that corresponds to the actual serial port on your system (PPI), as well as the SCO Merge device name that corresponds to the particular virtual COM port (VPI). You can use device definitions for com1 and com2 as examples to create your new virtual COM port definition. If you are using a serial card with special SCO Merge drivers provided, refer to the card manufacturer's instructions for creating a device definition.
For the direct attach definition, you will need to specify the physical IRQ number and the IO Port range that the serial device uses.
Printer administration
By default, SCO Merge sends all DOS and Windows printing jobs via the
UNIX print spooler to a printer named
doslp
.
The SCO Merge
installation routine automatically
attempts to configure your default UNIX
printer, if one exists, so it can also be used as the
default DOS printer doslp.
To determine whether doslp has been configured, type the
following
lpstat command
at the UNIX prompt:
lpstat -p doslp
This command tells you whether or not doslp is properly configured. If it is, you can start using this printer in your DOS and Windows sessions. For more information, see ``Printing from a DOS session'' and ``Printing from a Windows session'' in Chapter 3.
If it is not properly configured, you need to set it up yourself as described in the next section ``Configuring the default printer''.
You can also configure alternate printers for use in your DOS and Windows sessions. See ``Configuring multiple printers''.
If using the UNIX spoolers to print from your DOS or Windows application
does not work, you can try directly attaching the printer. See
``Configuring printers for direct attachment''.
Configuring the default printer
To configure doslp, use the standard UNIX procedures for setting
up local printers.
If you are working in the Desktop environment, use the SCOadmin Printer Manager utility on OpenServer systems, or the SCOadmin Printer Setup Manager utility on UnixWare systems.
If you are not working in the Desktop environment, use the scoadmin printer manager command on OpenServer systems, or scoadmin printer setup manager command on UnixWare systems.
Do the following when setting up a DOS printer:
dosmodel is a printer interface program similar to the standard printer model, except that it does not print banner pages at the beginning of each print job, and it does not output a form feed at the end of each print job. It is best to use this model because DOS print jobs are often split up under SCO Merge.
(dosmodel is always used as the printer model for doslp printer when it is automatically configured during SCO Merge installation.)
If your printer does not recognize the standard printer model, you should not use either the standard model or dosmodel. Instead, choose a printer model that is appropriate for your printer.
The default SCO Merge printer is always named doslp.
To change the physical printer to which doslp
refers, follow the standard UNIX procedures for configuring
printers.
Assign the name doslp to your preferred
printing device and choose an appropriate interface
program.
Configuring multiple printers
You can use printers other than doslp
for DOS and Windows printing. These printers can be either local or remote.
Assuming the printers you want to set up have been configured under UNIX, you can create definitions for them in the SCO Merge environment and then attach them to your DOS and Windows sessions.
To create a new printer definition from the Desktop environment, do the following:
The most important parameter in the print spooler definition is the printer command . This is the actual UNIX command that is used to print on your system. For example, if you have a UNIX printer named printer1, you may enter the following command in the Printer Command text box:
lp -dprinter1if that is the command you use to print under UNIX.
The printer command can also be any other UNIX command that operates on standard input. For example, you can run your printer output through a filter before spooling by using the following command:
filtername | lp -dprinter1
mrgadmin printer add token:filename:"full_name"
See ``Using mrgadmin'' in Chapter 6 for more information.
If you are using Windows 95, the new printer definition automatically becomes available to the Windows Add Printer Wizard utility under the token name you specify. See ``Setting up printers in Windows 95'' in Chapter 3.
If you are using DOS or Windows 3.1, you need to attach the new printer to your session to make it available in your DOS or Windows environment. See ``Printing through the UNIX system spooler'' in Chapter 4 for instructions on attaching printers.
Configuring printers for direct attachment
Under some circumstances, you may not want to use the UNIX spooling system for DOS printing. In these cases, you can attach a printer directly to a DOS or Windows session. Then, DOS or Windows directly controls the printer, and it is not available for UNIX printing. You can directly attach printers only to printer port LPT1.
Before you can use the printer under DOS or Windows, you must disable UNIX printing on that printer. See ``Disabling UNIX printing'' for instructions.
SCO Merge provides standard printer definitions to correspond to two standard parallel ports on your system. To use a directly attached printer under DOS or Windows, you can attach a printer connected to one of these ports using the Merge Setup utility as described in ``Directly attaching printers'' in Chapter 4.
You can examine the available printer definitions using the Merge Setup utility as follows:
Disabling UNIX printing
To disable UNIX printing, do the following:
disable doslp
While UNIX printing is disabled, users can continue spooling print jobs to that printer. However, the jobs are not printed until the printer is re-enabled for UNIX use.
Custom device administration
In addition to the standard hardware resources, SCO Merge
allows DOS and Windows to use custom hardware devices, such as
soundboards, scanners, and LAN cards, which are not
made available automatically as part of SCO Merge.
Some of these devices may come with drivers that support SCO Merge. In these cases, you can use the virtual attachment method to attach these devices to your DOS or Windows sessions. Consult the manufacturer's instructions for how to create custom virtual device definitions for such devices.
You can use the direct attachment method to attach devices that don't come with SCO Merge support in their drivers to DOS and Windows sessions. In this case, DOS and Windows drivers control the device hardware directly without intervention of SCO Merge or UNIX.
Limitations of direct attachment
Many factors can prevent a directly attached device from
working under SCO Merge. Some reasons
certain devices may fail are:
The game port is the only custom device that is predefined by SCO Merge.
If a game port exists on your system, you can attach it to your DOS or Windows session from the Desktop environment by simply selecting the game device in the Devices view of the Personal Merge Session Configuration window.
In a non-Desktop environment, use the +agame option with the dos or win command to start your DOS or Windows session or with the mrgconfig command to update your default configuration.
Only one DOS process at a time can use the game port. If the game port is not available because it is currently in use, SCO Merge displays a warning message.
Defining a direct attach custom device
To be able to attach a custom device to a DOS or Windows configuration, you must first create a device definition for it.
If you are working in a Desktop environment, follow these steps:
You have to specify various hardware characteristics of the device you are defining, so you should have that information ready. The parameters you can specify include:
You cannot choose an IRQ that another device will be using at the same time. Consult the manufacturer's documentation for the value to use. If this device must use a physical IRQ that has been assigned to another device, you can remap the IRQ to a virtual IRQ value.
SCO Merge uses the following IRQ numbers:
Valid DMA values are 0 through 7. If this device must use a DMA channel that another device is using, you can remap the DMA channel to a virtual DMA channel.
SCO Merge uses DMA channel 1 for the floppy controller.
The address is given in hexadecimal notation, and is typically in the range 0 - 3ff(hex). If this device must use an address range that another device is using, you can remap the address to a virtual address. You cannot choose a virtual address that another device is already using as a physical or virtual address at the same time as this device.
For a Memory Mapped I/O device, the range must start on a 4K boundary and be a multiple of 4K. If this device must use an address range that another device is using, you can remap the address to a virtual address. You cannot choose a virtual address that another device is already using as a physical or virtual address at the same time as this device.
In a non-Desktop environment, you can create a new custom device definition by using the mrgadmin command as described in ``Using mrgadmin'' in Chapter 6.
Making new DOS images
The DOS image is a file that reflects the configuration of your
virtual PC environment.
It is a
snapshot of DOS memory that is taken after DOS has been booted,
loaded into memory, and started.
This image includes information DOS needs about the system configuration, which is derived from the hardware installed on the system and the contents of special configuration files at the time the image is made. It allows quick start-up of a DOS program from the UNIX environment.
The default DOS images (for monochrome, CGA, and VGA
display modes) are contained in the following files:
/usr/merge/image/std/mono/*.img
/usr/merge/image/std/cga/*.img
/usr/merge/image/std/vga/*.img
(Hercules display mode uses the same files as monochrome mode.)
SCO Merge users use these DOS image files whenever they run a DOS or Windows session.
These standard DOS images are sufficient for most SCO Merge users in most situations. However, you may need to make new DOS images if you want to:
Typically, when new images are required, you create a new DOS image for all of the display modes. The new default images are available automatically to all users.
To create new DOS images, log in as root and follow the procedures in
``Steps to making DOS images''.
Making config.sys changes
Three special directories are created specifically for new images,
one directory for each image type you make:
/usr/merge/image/std/mono
/usr/merge/image/std/cga
/usr/merge/image/std/vga
Each directory has a file called config.sys. This config.sys file is used in the DOS session from which the DOS image is created, so all configuration parameters specified in it are automatically included in each DOS or Windows session started after the new image is created.
If you want to change the values of certain config.sys commands or add device drivers to your DOS image, log in as root, edit these config.sys files, and create new DOS images following the procedures in ``Steps to making DOS images''.
The following sections describe specific changes you can make to
config.sys files.
Changing special config.sys commands
SCO Merge allows you to use nearly all config.sys
commands as you would on a conventional DOS
computer.
Commands in the system-wide config.sys file affect all users when they start a DOS process. Commands in each user's home directory config.sys file affect only that user's DOS and Windows sessions. To examine or modify these config.sys files, you can use the Personal Merge Session Configuration option of the Merge Setup utility.
However, certain config.sys commands cannot be interpreted unless they are incorporated into the DOS image you are using. These commands include:
The BUFFERS
value is effective only when you use
an actual DOS file system.
It is not used when you
access the shared UNIX file system.
The FCBS command is effective only when you use an actual DOS file system. It is not used on any portion of the shared UNIX file system.
Do not edit the image configuration file /usr/merge/image/config.mki. The factory default images are made on the basis of the entries in this file. Altering any of its lines is likely to result in unexpected and undesirable SCO Merge behavior.
Adding device drivers to DOS images
If you want to load additional DOS drivers, you would normally add DEVICE= commands to your personal or system-wide config.sys files. These commands are interpreted, and the appropriate drivers are loaded each time the DOS sessions starts.
If you want to improve the DOS session start-up time, you can incorporate these drivers into the DOS images.
You might also want to try this with other config.sys commands that are executed with every DOS session that starts on your system.
However, not all device drivers can be successfully incorporated into DOS images, so some experimentation may be necessary.
When you want to add device drivers to your DOS images, follow these steps:
Normally, SCO Merge uses a standard ROM supplied (as a file) with the SCO Merge software. This results in your display being treated as a standard VGA display, when DOS or Windows runs in full-screen mode, regardless of what display adapter you are actually using on your system.
If you want to take advantage of the extended video modes of your display adapter, you can rebuild the DOS VGA image using the actual physical ROM on your card.
To make this VGA image using the on-card ROM, your computer must have a 100 percent VGA-compatible card. If your card is not fully compatible, the procedure for making a VGA image may fail. When the procedure fails, symptoms range from an error message like the one shown below to a system lock-up:
VGA Image was not made. (Incompatible VGA card?) (1)
To create a new VGA DOS image, follow the procedures in ``Steps to making DOS images''.
To create new DOS images, you have to be logged in as root since the new images are used for all DOS and Windows sessions on your system.
In the Desktop environment, start the Merge Setup utility and choose System-Wide Merge Administration from the list of configuration categories. To make new DOS images, click on the Create DOS images button.
mkimg
The mkimg utility creates new DOS images for all display cards.
To make a new VGA DOS image using data
from a VGA on-card ROM, type:
mkimg native vga
The mkimg utility creates a new VGA DOS image only.
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