Enables information about error conditions to be displayed. AUTOFAIL ------------|---------|---------------------------| |-- NO --| |-- YES --| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

This CONFIG.SYS statement allows the OS/2 operating system to display information about error conditions such as hard errors. A hard error is an error condition that requires you to reconfigure the system or remove the source of the error before the system can resume reliable operation.

The system default is AUTOFAIL=NO, which causes a window to appear that informs you of an error condition. The YES parameter causes the appropriate error code to appear rather than a window.

BASEDEV

Installs a base device driver by specifying the complete file name of the device driver in your CONFIG.SYS file. BASEDEV=-------------------- filename --|-------------|| |- arguments -| Related Commands: Device A device driver is a file that contains the code that the OS/2 operating system needs to recognize a device and correctly process information received from or sent to that device. A base device driver is one that is needed when the OS/2 operating system is first started.

The BASEDEV statement is used to load base device drivers. Device support for disks, diskettes, printers connected to the workstation, and other devices, is loaded with the BASEDEV statement.

Unlike the DEVICE statement, the BASEDEV statement cannot contain either drive or path information because the OS/2 operating system cannot process such information at the stage of the startup sequence when the BASEDEV statements are processed. The root directory of the startup partition is first searched for the specified file name, then the \OS2 directory of the startup partition. If drive or path information is included in a BASEDEV statement, an error is generated.

In addition, BASEDEV statements are not necessarily processed in the order in which they appear in your CONFIG.SYS file. The extensions of the file names specified in the BASEDEV statements are examined; the statements are then processed in the following order of file name extensions: .SYS .BID .VSD .TSD .ADD .I13 .FLT .DMD Files with other file-name extensions will not be loaded.

If several BASEDEV statements load file names with the same extension, those files will be loaded in the order in which they appear in the CONFIG.SYS file.

The following base device drivers are included with your OS/2 diskettes:
PRINT01.SYS Device support for locally attached printers on non-Micro Channel workstations.
PRINT02.SYS Device support for locally attached printers on Micro Channel* workstations.
IBM1FLPY.ADD Device support for diskette drives on non- Micro Channel workstations.
IBM2FLPY.ADD Device support for diskette drives on Micro Channel workstations.
IBM1S506.ADD Device support for non-SCSI disk drives on non-Micro Channel workstations.
IBM2ADSK.ADD Device support for non-SCSI disk drives on Micro Channel workstations.
IBM2SCSI.ADD Device support for Micro Channel SCSI adapters.
IBMINT13.I13 General-purpose device support for non- Micro Channel SCSI adapters.
OS2DASD.DMD General-purpose device support for disk drives.
OS2SCSI.DMD General-purpose device support for non- disk SCSI devices.

IBM1FLPY.ADD

|-------------| | BASEDEV= ---|---------|-|--------|-- IBM1FLPY.ADD --|----------|-|--| |- drive -| |- path -| |- /MCA -| |- /A: -| |- /IRQ: -| |- /DMA: -| |- /P: -| |- /U: -| |- /F: -| |- /CL: -| |- /SPEC: -| Related Commands: BaseDev Os2Dasd.Dmd

IBM1FLPY normally obtains diskette drive information from the host system BIOS. If the information supplied by the host system is incorrect or if the BIOS does not support a third or fourth floppy drive, it may be necessary to provide this information on the IBM1FLPY command line.

In addition, command line parameters may be used to support a second installed floppy controller which would not normally have host system BIOS support.

Examples:
Define a third 1.2MB Floppy drive: BASEDEV=IBM1FLPY.ADD /A:0 /U:2 /F:1.2MB Override the ChangeLine type for the (B:) drive: BASEDEV=IBM1FLPY.ADD /A:0 /U:1 /CL:NONE Support a 1.2MB OEM drive attached to a uChannel machine: rem BASEDEV=IBM2FLPY.ADD BASEDEV=IBM1FLPY.ADD /MCA /A:0 /U:1 /F:1.2MB Note: The /MCA option is required on MicroChannel systems. If it is not specified, the driver will automatically deinstall itself.

Support a second installed floppy controller: BASEDEV=IBM1FLPY.ADD BASEDEV=IBM1FLPY.ADD /A:0 /DMA:3 /IRQ:10 /P:370 /U:0 /F:1.44MB BASEDEV=IBM1FLPY.ADD /A:0 /DMA:3 /IRQ:10 /P:370 /U:1 /F:1.2MB Note: Choices of /DMA, /IRQ, and /P depend on the supplier of the floppy controller. Consult the supplier of the controller for the appropriate settings for these values.

The First drive supported by the second controller will be assigned B: if this drive letter is available. Specifing /A:1 will cause the second controller to be assigned drive other than A: or B:.

Parameters: /MCA Load on uChannel Machine /A: Adapter ID (0 - 1) /IRQ: Interrupt Level (0 - n) /DMA: DMA Channel Number (0 - n) /P: Controller I/O Address (hhhh) /U: Drive Number (0 - 3) /F: Drive Capacity (360KB...2.88MB) /CL: Changeline Type (NONE,AT,PS2) /SPEC: Controller Specify Bytes (hh,hh()

BREAK

Instructs DOS to check whether the Ctrl and Break keys have been pressed before carrying out a program request. BREAK ------------|---------|------------------------------| |-- ON --| |-- OFF --| Enter the BREAK command at the DOS command prompt to display the current status.

BREAK instructs the system to check if you pressed the Ctrl and Break keys together before the system carries out a program request. Pressing and holding the Ctrl and Break keys together stops a command from completing its task.

BREAK can be entered in the CONFIG.SYS file, in a batch file, or at the command prompt. If BREAK is ON, processing might be slower, but the operating system will probably intercept Ctrl+Break faster. Setting BREAK=ON allows you to leave a program even if it produces few or no standard device operations (such as a compiler). For example, if a program is being compiled and it meets an error or loop, it is important to have a way to stop compilation.

If you accept the system installation default for the BREAK statement, the installation program places the following in your CONFIG.SYS file: BREAK=OFF

BUFFERS

Sets the number of disk buffers that the system uses. BUFFERS = --------------------- x -------------------------| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

The disk buffer is a 512-byte block of storage the system uses to read and write blocks of data that do not occupy an entire sector. You can increase the speed of your system by increasing the value specified for BUFFERS. However, when you increase the number of disk buffers, you decrease your available memory. You might want to experiment with the number of buffers to get maximum performance. Additional buffers can cause some applications to run more slowly because there is less memory available for the application to keep data. More frequent read and write requests than are otherwise necessary might then result.

Buffering, which is the allocation of storage, is one memory management method.

By using the disk buffer, the operating system can read and write blocks of information. Once the information is read into the buffer, the system is ready to process the information. While the information is in the buffer or being processed, the input device can begin reading new pieces of information so the processor does not have to wait unnecessarily to process information and program instructions. The processor can complete its operation, because the next block of information to process is already in the buffer area.

Some other situations might also occur. For example, suppose the processor completes its work and there is no information in the buffer to process. The processor must wait until the next block of information is read into memory by the input device. Similarly, if the input device reads information into the buffer before the system has time to process the records, the buffer might reach its capacity and have to wait until the system accepts more information to process.

In your CONFIG.SYS file, there is a BUFFERS statement that determines the number of disk buffers that the operating system will keep in memory. Depending on how many programs you work with at a given time, you might want to experiment with this number to maximize performance on your system.

If you run many programs in OS/2 sessions, you can increase the speed of your system by increasing the value specified for BUFFERS (for example, BUFFERS=70). However, remember that when you increase the number of disk buffers, you decrease your available memory by 512 bytes for each buffer specified. Additional buffers might cause some programs to run more slowly because there is less memory available for the program to keep information. This can result in more frequent memory swapping, which will slow down performance.

CACHE

Specifies the parameters that the High Performance File System (HPFS) uses to write information to a disk. This command is specified as part of a RUN statement in the CONFIG.SYS file or entered at a command prompt. CACHE ---|---------------|----|----------------|--------- |- /LAZY:state -| |- /MAXAGE:time -| . . . . . .-------|------------------|----|--------------------|-----| |- /DISKIDLE:time -| |- /BUFFERIDLE:time -| Related Commands: IFS Hpfs.Ifs

If you enter this command without a parameter, the operating system displays the current values for CACHE.

You can use cache memory if you have:

Formatted the hard-disk partition during OS/2 installation
Selected the High Performance File System

The system installation program sets up caching for the primary partition through the OS2.INI file. The HPFS manages a cache of memory divided into blocks of 2KB. Data that is read from and written to the disk is transferred through this cache so that it can be used in satisfying future requests. This cache is separate from that of the BUFFERS and DISKCACHE commands discussed elsewhere in this reference.

When a user requests data that is not present in the cache, the HPFS selects the least recently used (LRU) block, writes the data within that block to disk if necessary, and then fills the block with the requested data. This significantly increases the chances that often-used data will be found in memory, thus saving the expense of a disk-read operation.

In addition, the file system takes advantage of its knowledge of cache block contents. Data, not expected to be reused soon by the file system, is placed in cache blocks marked for immediate reuse. In most cases, when a write request is received, it is not necessary to write the data immediately to disk. The HPFS takes such data and copies it to the block cache without actually performing the disk-write operation. Once the data is in the cache, it is written to disk as a background activity.

Also, because these lazy-writes are performed during disk idle time, incoming requests need not wait for large disk- write operations to be completed. This optimizes overall system throughput and response time for all requesting processes.

The HPFS also contains additional levels of caching that speed up access to directories. The HPFS uses this cache to quickly get to the directory on which the request is being made.

Note: If you set the /LAZY parameter to ON, select Shut down from the menu of the desktop before turning off your system. Failure to do so will cause loss of data if the contents of the HPFS cache buffers have not been erased and written to disk. For safety, and if performance is not a concern, use the /LAZY:OFF option, which causes a write through the cache to the disk.

COUNTRY

Identifies the following information for a country:

Date and time format
Decimal separator
Character-case map table
Collating-sequence table used by SORT
Double-byte character-set (DBCS) environment vector for double-byte characters.

COUNTRY = nnn -|-----------------------------------------|-| |-,--|---------|--|--------|--- filename -| |- drive -| |- path -| Related Commands: CodePage Date DevInfo KeyB Sort Time

This statement is one of the interrelated CONFIG.SYS statements required for successful code-page switching.

The country-dependent information used by the OS/2 operating system is determined by the COUNTRY statement that is active in the system. This country information is always the same for both operating environments.

The following table lists the country code and supported code pages for each country. The first code page listed for each country is the system default when a CODEPAGE statement is not specified in the CONFIG.SYS file. The CONFIG.SYS file does not change if the country information in the System Setup folder is changed. If your country is not listed, select the most similar country supported. Arabic-speaking Country Code: 785 Code Pages: 864 (Note 1), 437 Country Code: 785 Code Pages: 864 (Note 1), 850 Asian English Country Code: 099 Code Pages: 437, 850 Australia Country Code: 061 Code Pages: 437, 850 Belgium Country Code: 032 Code Pages: 437, 850 Canada (French-speaking) Country Code: 002 Code Pages: 863, 850 Czechoslovakia Country Code: 042 Code Pages: 852, 850 Denmark Country Code: 045 Code Pages: 865, 850 Finland Country Code: 358 Code Pages: 437, 850 France Country Code: 033 Code Pages: 437, 850 Germany Country Code: 049 Code Pages: 437, 850 Hebrew-speaking Country Code: 972 Code Pages: 862 (Note 1), 437 Country Code: 972 Code Pages: 862 (Note 1), 850 Hungary Country Code: 036 Code Pages: 852, 850 Iceland Country Code: 354 Code Pages: 850, 861 Italy Country Code: 039 Code Pages: 437, 850 Japan Country Code: 081 Code Pages: 932 (Note 2), 437, 850 Country Code: 081 Code Pages: 942 (Note 2), 437, 850 Korea Country Code: 082 Code Pages: 934 (Note 2), 437, 850 Country Code: 082 Code Pages: 944 (Note 2), 437, 850 Latin America Country Code: 003 Code Pages: 437, 850 Netherlands Country Code: 031 Code Pages: 437, 850 Norway Country Code: 047 Code Pages: 865, 850 Poland Country Code: 048 Code Pages: 852, 850 Portugal Country Code: 351 Code Pages: 860, 850 Republic of China Country Code: 088 Code Pages: 938 (Note 2), 437, 850 Country Code: 088 Code Pages: 948 (Note 2), 437, 850 Spain Country Code: 034 Code Pages: 437, 850 Sweden Country Code: 046 Code Pages: 437, 850 Switzerland Country Code: 041 Code Pages: 437, 850 Turkey Country Code: 090 Code Pages: 857, 850 United Kingdom Country Code: 044 Code Pages: 437, 850 United States Country Code: 001 Code Pages: 437, 850 Yugoslavia Country Code: 038 Code Pages: 852, 850 Note 1: Code pages 862 and 864 are supported only with a country supplement available only in certain countries.

Note 2: Code pages 932, 934, 938, 942, 944, and 948 are supported only with the Asian version of the OS/2 operating system on Asian hardware.

DEVICE

Installs a device driver by specifying the path and complete file name of the device driver in your CONFIG.SYS file. DEVICE=--|---------|-|--------|- filename --|-------------|| |- drive -| |- path -| |- arguments -| Related Commands: BaseDev

A device driver is a file that contains the code needed so that the OS/2 operating system can recognize the device and correctly process information received from or sent to that device. It loads standard default drivers that support standard system display terminals, keyboards, printers, diskette drives, hard disk drives, and serial devices. You can, however, replace these or add other devices by coding and loading a device driver using DEVICE statements in the CONFIG.SYS file. DEVICE statements are processed in the order in which they appear in the CONFIG.SYS file.

Any time you add or make changes to the CONFIG.SYS file, you must restart the system in order for the new device or change to become effective. Remember, the CONFIG.SYS file is read only during system startup. Anything added to this file after system initialization does not work until you restart the system.

Your OS/2 diskettes contain the following device drivers:
ANSI.SYS Allows extended screen and keyboard support for DOS sessions.
COM.SYS Allows OS/2 application programs or system programs, such as SPOOL, to use serial devices.
EGA.SYS Allows DOS programs that require Enhanced Graphics Adapter support to be run.
EXTDSKDD.SYS Allows access to an external diskette drive referencing a logical drive letter.
LOG.SYS Allows system error logging using the SYSLOG utility program.
MOUSE.SYS Provides support for pointing devices.
PMDD.SYS Provides pointer draw support for OS/2 sessions
POINTDD.SYS Provides mouse pointer draw support.
TOUCH.SYS Provides support for touch devices.
VDISK.SYS Installs a simulated disk called a virtual disk.
VEMM.SYS Provides DOS Expanded Memory Manager.
VXMS.SYS Provides DOS Extended Memory Specification.

The Device Support diskette that comes with the OS/2 operating system contains Printer device drivers. Refer to the Master Help Index for information about installing these files.

Both DOS and OS/2 device drivers can be loaded with the DEVICE statement. OS/2 device drivers are initialized when you start the OS/2 operating system and can process requests from either DOS or OS/2 programs. DOS device drivers are also initialized when you start the OS/2 operating system but they can only process requests from DOS programs.

You can also install a device driver by using one of the following:

OS/2 System Installation program
DDINSTAL command
System Editor

OS/2 System Installation is a menu-driven program designed to guide you through the installation process of installing OS/2 2.0 on all systems supported by OS/2 2.0. It installs the device drivers that are required for your system's operation. It also installs device drivers supplied on separate Device Support diskettes.

DDINSTAL provides an automated way to install device drivers after you have installed the OS/2 operating system. Any device that you can add comes with a separate diskette called a Device Support diskette. That diskette has a device driver profile (a file with a .DDP extension) that controls the installation process. DDINSTAL uses the information from that profile to add the necessary statements to CONFIG.SYS and to copy all the support files into their appropriate directories on the hard disk.

Some device drivers are very simple. They do not have, nor do they depend on, other support files to operate. Because of their simplicity, you can easily install these types of device drivers without much trouble by using an editor such as the System Editor and adding a DEVICE statement in your CONFIG.SYS file.

DEVICE - ANSI.SYS

Allows you to use extended keyboard and display support in DOS sessions. This device driver has no effect on OS/2 sessions. |-------------| | DEVICE= ---|---------|-|--------|-- ANSI.SYS --|----------|-|--| |- drive -| |- path -| |--- /X ---| |--- /L ---| |--- /K ---| Related Commands: Ansi

You specify this support by placing this DEVICE statement in your CONFIG.SYS file. Then, when you start the OS/2 operating system and switch to a DOS session, the standard input and standard output support is replaced with the extended functions. These functions allow you to redefine keys, manipulate the cursor, and change display color attributes. If you no longer want the extended functions for DOS sessions, you can remove the DEVICE=C:\OS2\MDOS\ANSI.SYS statement from your CONFIG.SYS file and restart the system.

DEVICE - COM.SYS

Allows OS/2 application programs or system programs, such as SPOOL, to use serial devices.

Device drivers that support serial ports COM1 through COM4 must be listed before the DEVICE=C:\OS2\COM.SYS statement in the CONFIG.SYS file, or the port will be unavailable to COM.SYS. DEVICE= ---|---------|-|--------|------ COM.SYS ---------| |- drive -| |- path -| The COM.SYS and COMDMA.SYS system files support ports COM1, COM2, COM3, and COM4.

This device driver supports applications with the following RS-232C (serial device) interface functions:

Duplex communication
Automatic flow control (XON/XOFF) for both transmit and receive
Various modem line handshaking modes
Standard and nonstandard baud rates
Receive data-error character replacement.

It also supports these system features:

Multiple active COM ports
Read and write request queueing
Interrupt-driven I/O processing
Internal transmit and receive data buffers
Several device status query functions.

COM.SYS does not provide any support for devices that are attached to the COM port. Instead, it provides enabling support for the asynchronous communications interface itself. Application programs, subsystems, and system programs must provide the support needed to use devices attached to the COM port.

This device driver allows other device drivers that support specific COM ports to be installed, provided that they are listed before COM.SYS in the CONFIG.SYS file. This allows support for:

A special device for an application program's use that is not adequately supported by this device driver
Additional COM ports beside COM1 through COM4
Enhanced device driver function for a COM port (which might be required for certain subsystem support).

DEVICE - EGA.SYS

Supports the EGA register interface. DEVICE= ---|---------|-|--------|------ EGA.SYS ----------| |- drive -| |- path -| The EGA.SYS device driver provides support for the EGA register interface in DOS sessions. EGA.SYS must be installed for those application programs that use the EGA register interface.

DEVICE EXTDSKDD.SYS

Allows you to access a disk using a logical drive letter. DEVICE= ---|---------|-|--------|------ EXTDSKDD.SYS------- |- drive -| |- path -| |-------------------------------| | . . . . . .-----|------ /D:d ------|---------------------------------| |------ /T:t ------| |------ /S:s ------| |------ /H:h ------| |------ /F:f ------| More than one external device driver can be installed at the same time. The maximum number is the total number of physical diskette drives installed in your system. Installed virtual disks do not affect the drive letter assignments described here if DEVICE=C:\OS2\VDISK.SYS statements are listed after DEVICE=C:\OS2\EXTDSKDD.SYS statements in the CONFIG.SYS file.

The first physical internal diskette drive is designated drive A. The second internal diskette drive is designated drive B. Other devices or device drivers are assigned letter values (beginning with C) based on the order in which they are encountered. The existence of internal diskette drives and hard disks is checked first; then the CONFIG.SYS file is checked for device drivers. For the OS/2 operating system to recognize an external physical device, the CONFIG.SYS file must have the correct device driver information.

The drive letter B is automatically used, even if there is only one physical drive; thus, a machine with only one diskette drive has two logical diskette drives: A and B. In this case, a specified parameter of /D:1 is an error. The first hard disk or the first block device driver cannot assign a drive letter lower than C.

DEVICE - LOG.SYS

Activates the System Logging Service device driver. DEVICE = -----|---------|-|--------|---- LOG.SYS --------- |- drive -| |- path -| . . . . . . -----------|--------|-|--------|--|--------|-------------| |- /E:x -| |- /A:x -| |- /OFF -| Related Commands: SysLog Run (Logging)

You must include a RUN=LOGDAEM.EXE command in the CONFIG.SYS file in addition to this DEVICE=LOG.SYS statement. These two commands and their parameters allow the System Logging Service to retrieve log data and keep the data in specific error-log files. LOG.SYS is the file name of the System Logging Service device driver.

DEVICE - MOUSE

Implements support for pointing devices. To effectively use a mouse, you must also load the POINTDD.SYS device driver. In addition, you must include these statements in the CONFIG.SYS file in the following order:

A device-dependent statement that gives the file name containing the information for the mouse you use, along with its model number and the COM port to which it is connected
A device-independent statement that identifies the mouse to MOUSE.SYS

All statements for serial mouse device drivers must precede any COM.SYS statements in the CONFIG.SYS file so that both device drivers are installed correctly.

Device Dependent Statement DEVICE = ---|---------|---|--------|----- filename -------- |- drive -| |- path -| . . . . . . .------|---------------|---------------------------------| |- SERIAL=COMn -| Device Independent Statement DEVICE = ---|---------|---|--------|----- MOUSE.SYS ------- |- drive -| |- path -| . . . . . .------|-------------|-------------------------------------| |- QSIZE=q -| |- TYPE=name -| If you want to install an IBM Personal System/2* Mouse on your computer, type the following in the CONFIG.SYS file:

DEVICE=C:\OS2\POINTDD.SYS DEVICE=C:\OS2\MOUSE.SYS Assume you want to install the PC Mouse System serial mouse on your computer and have it use COM port 2 for all sessions. You would type the following in the CONFIG.SYS file:

DEVICE=C:\OS2\POINTDD.SYS DEVICE=C:\OS2\PCLOGIC.SYS SERIAL=COM2 DEVICE=C:\OS2\MOUSE.SYS TYPE=PCLOGIC$ DEVICE=C:\OS2\COM.SYS Note: For IBM PS/2* Models 90 and 95, the final DEVICE= statement should be: DEVICE=C:\OS2\COMDMA.SYS COM.SYS must be loaded after the mouse statements so that the mouse can gain access to the COM port. For all PS/2 models except Models 90 and 95, the device driver is COM.SYS. For models 90 and 95, the device driver is COMDMA.SYS. The preceding example dedicates the COM2 port to the mouse. When your system is started, the mouse device driver is loaded and takes the COM2 port, leaving the COM1 and COM3 ports available for the COM.SYS device driver to use. You then get a message, as the COM.SYS device driver is being installed, that tells you that the installation on COM2 port was not successful. This message is followed by an additional message:

The device adapter could not be located.

The device adapter is not available because the port has been claimed by the mouse.

DEVICE - PMDD.SYS

Provides pointer draw device-driver support for OS/2 sessions. DEVICE= ---|---------|-|--------|------ PMDD.SYS ----------| |- drive -| |- path -| The DEVICE=PMDD.SYS statement is added to your CONFIG.SYS file when you install the OS/2 operating system. When the system starts, it uses the PMDD.SYS device driver to provide pointer draw support for OS/2 sessions.

If the PMDD.SYS device statement is removed from your CONFIG.SYS file, your system will not restart. If this happens, do the following:

Insert the OS/2 Installation Program diskette. When the logo screen appears, proceed to the Welcome screen and press Esc.
Copy the file, CONFIG.BAK, into the root directory. You now have a generic backup CONFIG.SYS file that you can rename to be your CONFIG.SYS file.
Use the System Editor to edit the CONFIG.SYS file.
Restart the system.

The following shows the PMDD.SYS statement. DEVICE=C:\OS2\PMDD.SYS

DEVICE - POINTDD.SYS

Provides mouse-pointer draw support. To effectively use a mouse, you must load this device driver, in addition to specifying the appropriate mouse device-driver statements in the CONFIG.SYS file.

DEVICE= ---|---------|-|--------|------ POINTDD.SYS--------| |- drive -| |- path -| Related Commands: Device Mouse

Text modes 0, 1, 2, 3, and 7 are the only modes supported. For graphic modes D, E, F, and 10, the EGA.SYS device driver must also be installed.

POINTDD.SYS provides draw support in all text modes for OS/2 sessions; POINTDD.SYS tracks (provides mode information) for all advanced function modes on the 8514A. It tracks for CGA, EGA, and VGA graphic modes in OS/2 sessions.

Implements support for touch devices. For a touch device to be effectively used, the POINTDD.SYS device driver and appropriate mouse device-driver support must be loaded. In addition, these statements must be included in the CONFIG.SYS file in the following order:

A device-dependent statement that gives the name of the file containing the information for the touch device you use.
A device-independent statement that identifies the touch device to TOUCH.SYS

Device Dependent Statement DEVICE = ---|---------|---|--------|----- filename -------- |- drive -| |- path -| . . . . . . . . . . . . . .---------CODE-------------INIT------------| Device Independent Statement DEVICE = ---|---------|---|--------|----- TOUCH.SYS ------- |- drive -| |- path -| . . . . . .------|-------------|-------------------------------------| |- QSIZE=q -| |- TYPE=name -| When the OS/2* operating system detects a touch device installed on your computer, the Install program automatically loads the required device-driver support necessary to enable the touch device. The touch device shares the auxiliary device (mouse) port on the system with the mouse by allowing the mouse to connect to the touch device, which is then connected to the system.

The Install program automatically adds the following statements to the CONFIG.SYS file: DEVICE=C:\OS2\PDITOU0x.SYS CODE=C:\OS2TOUCO21.BIN INIT=C:TOUCH.INI DEVICE=C:\OS2\TOUCH.SYS TYPE=PDITOU$ RUN=C:\OS2\CALIBRATE.EXE-C C:\OS2CALIBRAT.DAT DEVICE=C:\OS2\MOUSE.SYS TYPE=PDIMOU$ where x is 1 or 2 depending on the bus architecture of your computer, TOUCO21D.BIN is the touch-device microcode binary file, and TOUCH.INI is a text file containing default parameter settings.

The RUN=CALIBRAT.EXE statement is to activate the Calibration program. This program performs the dual actions of downloading calibration-constant data to the touch device each time the system is started, and enabling recalibration of the touch device at initial setup, and when the device is moved to a new location.

To recalibrate the touch device, enter the following at an OS/2 command prompt: C: CD \OS2 CALIBRAT -U Note: The use of the "-U" option updates the existing CALIBRAT.DAT file with new calibration data.

DEVICE - VDISK.SYS

Installs a virtual disk.

Any DEVICE=C:\OS2\VDISK.SYS statements must be listed after any DEVICE=C:\OS2\EXTDSKDD.SYS statements in CONFIG.SYS to avoid affecting logical drive letter assignments. DEVICE= -------|---------|---|--------|---- VDISK.SYS ----- |- drive -| |- path -| . . . . . .--|----------------------------------------------------|--| |-|- bytes -|--|-------------------------------------| |-- , ---| ||- sectors --|---|-------------------| |---- , ---| |-|- directories -|-| |----- , ------| The parameters, bytes, sectors, and directories are positional parameters. Use a comma when you do not want to alter the default value of the parameter for which the comma is being used. This tells the system to skip past the value it is looking for at this position, insert the default value, and proceed to the next value.

The following example shows how to install a 160KB virtual disk with 128-byte sectors and 64 directory entries. Note that all parameters are being specified.

DEVICE=C:\OS2\VDISK.SYS 160 128 64 If you decide to use the default value of any of the parameters, such as the sector size and directory entries, you can enter commas where the values should be.

DEVICE=C:\OS2\VDISK.SYS 160,, Assume that you want to specify a value for directories and accept the defaults for bytes and sectors. The value for directories should be preceded by two commas, as in this example: DEVICE=C:\OS2\VDISK.SYS ,,32 However, to indicate only the sectors parameter as the default, you must use two commas as follows: DEVICE=C:\OS2\VDISK.SYS 160,,64 VDISK displays a message to tell you that it is installed and gives you the drive letter that is assigned to the virtual disk.

If the virtual disk size specified is too large to fit in storage, VDISK tries to make a 16KB virtual disk. This may result in a virtual disk with a different number of directory entries than the number you specified with directories.

DEVICE - VEMM.SYS

Provides Expanded Memory Manager (EMM) for DOS sessions. DEVICE= ---|---------|-|--------|-- VEMM.SYS --|-----|----| |- drive -| |- path -| |- n -| Related Commands: ProtectOnly

VEMM.SYS is a virtual device driver that provides the Lotus**/Intel**/Microsoft** (LIM) Version 4.0 Expanded Memory Specification (EMS) emulation to DOS sessions. VEMM.SYS allows DOS applications to allocate and map expanded memory on the Intel 8086 family of computers.

Any DEVICE=C:\OS2\VEMM.SYS n statements must be listed before any DEVICE=C:\OS2\MDOS\VXMS.SYS statements in the CONFIG.SYS file since VEMM searches for unused addresses between 640KB and 1MB.

The following example shows the statement you type in the CONFIG.SYS file: DEVICE=C:\OS2\VEMM.SYS n

DEVICE - VXMS.SYS

Provides Extended Memory Specification (XMS) for DOS sessions.

DEVICE= --|---------|-|--------|-- VXMS.SYS --|----------------|--| |- drive -| |- path -| |- XMMLIMIT=g,i -| |--- HMAMIN=d ---| |- NUMHANDLES=n -| |----- UMB ------| |---- NOUMB -----| VXMS.SYS is a virtual device driver that provides Extended Memory Specification (XMS) emulation to DOS sessions. XMS allows DOS applications to access more than 1MB of memory, under XMS control.

If multiple DOS session support is requested during Installation, the system places the following statements in the CONFIG.SYS file to provide the XMS, VDD, and Load DOS High support to DOS sessions. DOS=HIGH,UMB DEVICE=C:\OS2\MDOS\VXMS.SYS /UMB Any DEVICE=C:\OS2\MDOS\VXMS.SYS statements must be listed after DEVICE=C:\OS2\VEMM.SYS statements in the CONFIG.SYS file because VXMS reserves all available addresses between 640KB and 1MB for use as upper memory blocks (UMBs). VXMS will not be installed if some other device driver has already reserved the region from 1MB to 1MB+64KB.

DEVINFO

DEVINFO statements prepare a device (such as your keyboard, display terminal, and printer) for code-page switching. Separate DEVINFO statements are required for each device to be used for code-page switching.

DEVINFO--|---------|-|--------|- filename --|-------------|| |- drive -| |- path -| |- arguments -| There are three different DEVINFO statements you can use:

KBD Prepares a keyboard for code-page switching. The keyboard statement specifies your keyboard layout ID (keyboard country and subcountry codes) and a file named KEYBOARD.DCP that contains a keyboard layout table for translating keystrokes into the characters of each code page supported by the OS/2 operating system. Refer to the KEYB command for a table containing the keyboard country and subcountry codes.

SCR Prepares a display screen for code page switching. The display statement specifies your display name and a file named VIOTBL.DCP that contains a video font table for displaying characters in each of the code pages supported by the OS/2 operating system.

LPT# Prepares a printer for code page switching. The printer statement specifies your printer name and a file with a .DCP extension that contains a printer font table for each code page supported by the OS/2 operating system.

Prepares a display for system code-page switching.

DEVINFO = SCR -- ,device, -|---------||--------|- filename -| |- drive -||- path -| This statement is one of the interrelated CONFIG.SYS statements required for successful code-page switching. The other statements are: CODEPAGE and COUNTRY

The display statement specifies your display name and a file named VIOTBL.DCP that contains a video font table for displaying characters in each of the code pages supported by the system.

To prepare a VGA display, type the following in the CONFIG.SYS file: DEVINFO=SCR,VGA,C:\OS2\VIOTBL.DCP

Prepares a keyboard for system code-page switching. DEVINFO = KBD--- ,layout, -|---------||--------|- filename -| |- drive -||- path -| This statement is one of the interrelated CONFIG.SYS statements required for successful code-page switching. The other statements are: CODEPAGE and COUNTRY

The DEVINFO=KBD statement specifies your keyboard layout and a file named KEYBOARD.DCP that contains a keyboard layout table for translating keystrokes into the characters of each code page supported by the system.

To prepare a U.S. keyboard using the keyboard layout, US, type the following in the CONFIG.SYS file:

DEVINFO=KBD,US,C:\OS2\KEYBOARD.DCP Remember the following if you want to prepare an enhanced keyboard. All countries have at least one Sub-Country code supported by the OS/2 operating system. Several countries such as France, Italy, and the United Kingdom have two. Because these countries have more than one keyboard layout, the subcountry code allows you to select the keyboard you want. If you do not specify a subcountry code for these countries, DEVINFO uses the default subcountry codes: FR189 (for France), IT141 (for Italy), and UK166 (for the United Kingdom).

To prepare the enhanced French keyboard 120, type the following in the CONFIG.SYS file:

DEVINFO=KBD,FR120,C:\OS2\KEYBOARD.DCP Prepares a parallel printer for system code-page switching.

DEVINFO = PRN -|-,device, -|---------||--------|- filename - LPT# -| |- drive -||- path -| . . . . . ----|----------------------------------|-------------------| |- ,ROM= --|------- nnn --|-----|--| | | | | |-- , ---| | |--- (nnn,fontid) -|-| | |----- , -------| This statement is one of the interrelated CONFIG.SYS statements required for successful code-page switching. The other statements are: CODEPAGE and COUNTRY.

This DEVINFO statement specifies your printer name and a file with a .DCP extension that contains a printer font table for each code page supported by the system.

If you want to prepare a Proprinter Model II as your first parallel printer, type the following statement in the CONFIG.SYS file: DEVINFO=LPT1,4201,C:\OS2\4201.DCP,ROM=(437,0)

If you want to use fonts other than the defaults, include the code page and font combinations on the ROM parameter in the correct order (imbedded fonts first). For example, if you want to set up an IBM Quietwriter III and use code page 850 and 860, in addition to 437, enter: DEVINFO=LPT1,5202,C:\OS2\5202.DCP,ROM=(437,011), (437,085),(437,254), (437,159),(850,254),(850,159), (860,011),(860,085) This statement must appear as one line in your CONFIG.SYS file.

If you do not correctly specify the required file names, or if you specify incorrect code pages in your CODEPAGE statement (those other than the two supported by the country code in your COUNTRY statement), the device is not prepared for code page switching. If a drive and path are not specified, the operating system looks for the file in the root directory of the default drive.

Also, remember that the keyword ROM is significant only for printers. Each ROM specification can be a pair of values enclosed in parentheses, where the first value is the system code page, and the second value is the number of a font that is in read-only storage or in a cartridge installed in the printer. If multiple fonts are not used, specify only the system code pages, separated by commas and without the parentheses.

DISKCACHE

Specifies the number of blocks of storage to allocate for control information and for use by the disk cache. DISKCACHE = ---- n --|-------|-|------|-|---------|------| |- ,LW -| |- ,T -| |- ,AC:x -| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

The disk cache allows a portion of the system storage to be used as an additional hard disk buffer. DISKCACHE speeds up application programs that read hard disks by keeping hard disk data frequently accessed in a cache buffer. When an application program requests hard disk data that is already in the cache buffer, the disk cache sends the data directly to the application program. This method of accessing data is much faster than if the data had to be read from the disk each time.

Specifying this statement increases the speed of your system. However, when you increase the size of your disk cache you also decrease the size of available storage. For this reason, you may want to experiment with the number of blocks you specify to get maximum performance. The recommended disk cache sizes should be based on the amount of memory that is available in the system, not the disk size.

Note: You need to select Shut down from the menu of the desktop before turning off your system. Failure to do so can cause loss of data if the contents of the cache buffers have not been erased and written to disk.

General DISKCACHE parameters size guidelines are as follows:

Systems with up to 5MB of physical memory should use a disk cache size of 64KB.
Systems with 6MB or more of physical memory should use a disk cache size of 256KB.
In most situations a threshold size of 32 is recommended

The amount of storage required for control information is determined by the total size of one or more hard disks. When the amount of storage you specify in the DISKCACHE statement is not available, the system displays an error message. When the amount of storage you specify in the DISKCACHE statement is not sufficient to support the total hard disk size, the disk cache does not work. The disk cache is allocated at system startup, and there is no dynamic adjustment of its size.

It is recommended that the threshold size be set at 32 unless the software product you are using is disk intensive and the manufacturer supplies information on the block size required. If the block size is defined in terms of byte count, divide the byte count by 512 and round up the quotient to the nearest whole number to determine the threshold value.

The disk device driver for the Personal System/2 Models 55sx, 65, 70, 80, 90, and 95 provides direct-access storage disk- cache support for use with hard disks. This device driver controls operation of the cache, which is allocated by the system and taken out of storage above 1MB. The cache is run as a write-through cache to maintain data integrity. Sectors passed to the disk device driver for writing on the disk are guaranteed to be written out to the disk on successful return from the device driver.

DOS

Specifies whether the DOS kernel will reside in the high memory area (HMA) and whether the operating system or DOS applications will control upper memory blocks (UMBs). DOS=-----|- HIGH -|--,---|-- UMB --|----------------| |- LOW --| |- NOUMB -| Related Commands: DeviceHigh LoadHigh

You need to have a DOS=HIGH/LOW,UMB/NOUMB statement in the CONFIG.SYS file to determine if the DOS kernel resides in high or low memory and to determine the control of upper memory blocks (UMBs). Upper memory blocks are provided by the XMS device driver. Therefore, you must have a VXMS.SYS statement in your CONFIG.SYS file to have upper memory blocks available.

Note: The high memory area (HMA) refers to space between 1MB and 1MB + 64KB. Upper memory blocks (UMBs) are between 640KB and 1MB.

If DOS=HIGH/LOW,UMB is in the CONFIG.SYS file, the operating system controls the upper memory blocks. This means that DOS applications can be loaded into upper memory but cannot allocate UMBs.

If DOS=HIGH/LOW,NOUMB is in the CONFIG.SYS file, the operating system will not control any UMBs and DOS applications can allocate UMBs but cannot be loaded there. DOS=HIGH/LOW,NOUMB must be specified in the CONFIG.SYS file for a DOS application to allocate UMBs.

Note: The high memory area (HMA) refers to space between 1MB and 1MB + 64KB. Upper memory blocks (UMBs) are between 640KB and 1MB.

If DOS=HIGH/LOW,UMB is in the CONFIG.SYS file, the operating system controls the upper memory blocks. This means that DOS applications can be loaded into upper memory but cannot allocate UMBs.

FCBS

Determines file-control-block (FCB) management information for DOS sessions.

This statement has no effect in OS/2 sessions. FCBS = ----------------- m ,n -----------------------| Type this command in the CONFIG.SYS file; do not enter the command at a command prompt.

A file control block (FCB) is a record that contains all of the information about a file (for example, its structure, length, and name). If a program tries to open more than the number of files specified in the FCBS statement, the system closes the least-recently used file control block and opens the new file.

Some application programs use file control blocks to create, open, delete, read, and write to files. New programs written for the operating system usually use internal file IDs (handles) for file input/output.

If a program tries to open more than the number of file control blocks specified in the FCBS statement, the system closes the least-recently used FCB and opens a new file. The files that are protected from being closed are not included in the list of least-recently used FCBs. If a program tries to read or write to a file that has been closed because it is the least-recently used FCB, the system displays an error message.

In addition, the value of the first number must be greater than or equal to the value of the second number. If you set the two values equal to each other in the FCBS statement and a program tries to open more than the total number of file control blocks you specified, no files can be closed. If a program tries to open more than the number of file control blocks you specified, no new files are opened.

FILES

Determines the maximum number of files available in DOS sessions.

This statement has no effect in OS/2 sessions. FILES = --------------------- n-------------------------| Type this command in the CONFIG.SYS file; do not enter the command at a command prompt.

When a DOS session is started, 20 files are available to be used by all programs running in that DOS session. A file is in use when a program is processing some kind of operation in it. When a program is using a file for its operation, that file is unavailable to another program. The file is returned to availability when the program has finished its operation and the file is closed.

Regardless of the FILES= setting, all DOS programs are initialized to a maximum of 20 files. It is the responsibility of an application to increase the number of files up to the maximum set by the FILES= statement.

Placing a FILES= statement in the CONFIG.SYS file increases the default value for all DOS sessions. Each session can also be customized by changing the appropriate DOS setting.

DEVICE - FSFILTER.SYS

DEVICE= ---------------- FSFILTER.SYS ----------| Related Commands: FsAccess VmDisk

Related Information: Starting a Specific Version of DOS

FSFILTER is a DOS device driver that provides access to OS/2 disk partitions when running a specific version of DOS. This device driver is provided in the OS2\MDOS directory, and must be loaded by the CONFIG.SYS file that is processed by the specific version of DOS.

Do this by copying FSFILTER.SYS to the diskette or disk partition that will be started, and add the following statement to the CONFIG.SYS file of the diskette or disk partition from which the DOS session will be started. DEVICE=FSFILTER.SYS The FSFILTER statement must be the first DEVICE= statement in the CONFIG.SYS file. In addition, it must precede any statement with a reference to a file stored in an HPFS partition.

IFS

Installs a file system (IFS) by specifying the path and complete file name of the file system driver in your CONFIG.SYS file. IFS = --|---------|-|--------|- filename --|-------------|| |- drive -| |- path -| |- arguments -| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

Related Commands: Cache ChkDsk Format IFS Hpfs.Ifs

A file system driver is a file that contains code needed to manage disks and diskettes formatted for file systems other than the file allocation table (FAT).

Any time you add or make changes to the CONFIG.SYS file, you must restart the system in order for the new file system or change to become effective. Remember, the CONFIG.SYS file is read only during system startup. Anything added to this file after system initialization does not work until you restart the system.

Use this command to replace the FAT file system with a file system of your choice. This enables you to:

Use large disks more efficiently
Have greater file flexibility
Increase system performance
Have more than one active file system.

An example of an IFS driver is HPFS.IFS

Specifies the file system program for loading the High Performance File System (HPFS). IFS = -----|---------|-|--------|-- filename --|-----------|- |- drive -| |- path -| |- /C:nnnn -| . . . .----------|------------------|---|------------|---------------| |- /AUTOCHECK:xxx -| |- /CRECL:x -| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

Related Commands: Cache ChkDsk Format IFS

Use this command to replace the FAT file system with a file system of your choice such as HPFS. This enables you to:

Use large disks more efficiently
Have greater file flexibility
Increase system performance
Have more than one active file system.

During OS/2 installation, you were given the option of installing the High Performance File System (HPFS). The features of this file system include the following:

Cache Memory Access The High Performance File System uses a high-speed buffer storage, known as a cache, to access programs and data. Often-used programs and data can be found in memory, thereby reducing the number of times the operating system must read a disk. The maximum amount of memory that can be used as a cache is 2MB regardless of how much memory is available.
Long File Names HPFS accepts file names of up to 254 characters in length. It also accepts any number of separators (.) as part of the file name.
File Allocation HPFS attempts to keep disk allocation for a file in contiguous sectors. Because most files will be located in adjacent sectors, the number of operations needed to access the file is reduced.
Extended Attributes HPFS supports extended directory information about files and directories. This information is called an extended attribute. Through extended attributes, an application can attach information to a file or directory.
"Lazy" Writing HPFS copies data to an area in cache memory before writing data to a disk according to the IFS statement specified in a CONFIG.SYS file. During OS/2 installation, the following IFS statement was added to the CONFIG.SYS file if you selected the High Performance File System: IFS=C:\OS2\HPFS.IFS /C:64
Balanced Directory Tree HPFS keeps track of files through a structure known as a balanced directory tree. To locate a file, HPFS reads this structure rather than reading the full directory list. HPFS is an installable file system (IFS) designed to provide better performance than the existing file allocation table (FAT) based file system. HPFS is designed to provide extremely fast access to very large disk volumes. The OS/2 operating system also supports the coexistence of multiple, active file systems on a single personal computer system, with the capability of multiple and different storage devices.

If you select HPFS as your standard file system, the OS/2 installation procedure inserts an IFS statement as the first entry in the CONFIG.SYS file.

System installation automatically sets up the HPFS cache for you if you format the primary partition with HPFS (using the OS2.INI file). If you format the primary partition for FAT instead, and then later want to format another partition with HPFS, you need to add an IFS statement to the CONFIG.SYS file.

Keep in mind that these statements are device-dependent and must be included before any DEVICE statements.

Note: Refer to the individual commands for further information on IFS, CACHE, and RUN statements.

If you start DOS (from outside the OS/2 operating system, that is, from a DOS partition or diskette), files on HPFS partitions are not accessible. If you start a Specific Version of DOS from within the OS/2 operating system (that is, a version of DOS running in a DOS sesssion), then files on HPFS partitions are accessible.

Both the FAT-based file system and installable file systems support standard naming conventions and the existing logical file and directory structure. Features of HPFS include:

File names up to 254 characters in length
Fast access to very large disk volumes
Strategic allocation of directory structures
Extended attribute support
Caching of directories, data, and file system structures
Processing of metacharacters that are generally used for displaying and printing graphics.
Large file support.

IOPL

Allows I/O privilege to be granted to requesting processes in OS/2 sessions. IOPL = ---------------|------- NO -----|-------------------| |------ YES -----| |------ list --|-| | |---- , ----| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

The privilege level assigned to a program determines what code segments and data segments it can access. The privilege level also limits the machine instructions a program can process.

Application programs are usually assigned privilege level 3. This means that they can call routines that run at any other privilege level. However, they can access only their own data segments and cannot issue any I/O instructions.

Programs that are granted I/O privilege run at privilege level 2. When IOPL is YES, a program assigned privilege level 2, such as a subsystem that needs to communicate directly with a specific device, is then permitted to send or receive instructions to or from that device.

LASTDRIVE

Specifies the maximum number of drives that are accessible.

This statement has no effect in OS/2 sessions. LASTDRIVE = --------------------- x-------------------------| Type this command in the CONFIG.SYS file; do not enter the command at a command prompt.

The value you specify with this command represents the last valid drive that is recognized.

LIBPATH

Identifies the locations of dynamic link libraries for OS/2 programs. LIBPATH = ------|---------|---- path -------|-------------| |- drive -| | | | |------------- ; --------------| LIBPATH is used to identify a set of directories to be searched when the OS/2 operating system loads dynamic link libraries. Because dynamic link library modules are shared globally, this command allows path searching to be defined globally rather than on a per-process basis (as done by the PATH command).

LIBPATH is not a part of the environment and therefore cannot be viewed with the SET command. Also, unlike the PATH environment variable, the current directory is not searched first.

The installation program places this statement in your CONFIG.SYS file: LIBPATH=C:\OS2\DLL;C:\OS2\MDOS;C:\;

LOADHIGH

Loads Terminate and Stay Resident (TSR) DOS programs into an available upper memory block (UMB) for a DOS session. LOADHIGH --|---------|-|--------|- filename -|-------------|-| LH |- drive -| |- path -| |- arguments -| Related Commands: DeviceHigh Dos (UMB/NOUMB)

You can load a DOS TSR program into an upper memory block (UMB) by typing the LH or LOADHIGH command at the DOS command prompt. If no UMB is available, the TSR program will be loaded into low memory (below 640KB). To enable UMBs, type the DOS=UMB statement in the CONFIG.SYS file.

MAXWAIT

Sets the amount of time a process waits before the system assigns it a higher priority.

When a regular-class thread is denied the processor for a defined number of seconds, it receives a temporary increase in priority for a minimum time slice. MAXWAIT = --------------------- x -------------------------| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

Related Commands: Priority Threads TimeSlice

The system limits the time that a regular-class thread waits to be processed. When the time limit is reached, the system raises the priority of the thread to give it a chance to be processed.

The most appropriate amount of time to set depends on the number of applications that must run concurrently and the kinds of activities the applications perform (the system default is three seconds). Experiment with this time to improve overall system performance.

MEMMAN

Selects storage allocation options for the OS/2 environment. |-------- , ----------| | MEMMAN = --------------|--|-- SWAP --|---|-|--------------| | |- NOSWAP -| | |--|-- MOVE --|---| | |- NOMOVE -| | |---- PROTECT ----| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

Related Commands: SwapPath

Applications consist of groups of segments that can be either loaded into physical memory at the same time or called when needed. If not enough memory is available to satisfy a request, the system attempts to provide more memory by writing the least frequently used data segments to a temporary file on a disk. This file is called a swap file.

Segments in the swap file are brought back into memory only as needed. Swapping makes it possible for applications to overcommit the amount of physical memory in the system.

If the system is started from a hard disk, swapping (SWAP) is the system default; from a diskette, the default is no swapping (NOSWAP).

PAUSEONERROR

Allows or prevents pausing when error messages are issued during the processing of the CONFIG.SYS file. PAUSEONERROR = --------|-- YES --|-------------------------| |- NO -|

PRINTMONBUFSIZE

Sets parallel-port device-driver buffer size. PRINTMONBUFSIZE = ------ x,-- x,-- x--| Type this command in the CONFIG.SYS file; do not enter the command at a command prompt.

The PRINTMONBUFSIZE= statement enables you to increase the size of the parallel-port device-driver buffer and thereby increase performance of data transfer to devices connected to the parallel port. The parallel port device driver will allocate and register its monitor chain buffer based upon the value specified.

The parallel port device driver is loaded automatically at startup by the operating system. It does not require a DEVICE= statement in the CONFIG.SYS file and, therefore, must have a separate statement to specify the buffer size for LPT1, LPT2, and LPT3.

PRIORITY

Selects priority calculation in scheduling regular-class threads. PRIORITY = -----------|--- DYNAMIC ----|-------------------| |-- ABSOLUTE ----| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

Related Commands: MaxWait TimeSlice Threads

The system assigns a regular-class thread to any of 32 priority levels and dispatches it based on its display status (background or foreground), recent input and output activity, and frequency of processor use. Most threads are assigned regular priority.

Applications can adjust priorities, but the system has a built-in method of handling access to the processor. The default method is Dynamic. Changing this to Absolute can help achieve predictable results by determining the order of priority strictly on the basis of class and level.

PRIORITY_DISK_IO

Specifies disk input/output priority for applications running in the foreground. PRIORITY_DISK_IO = ---|--- YES ----|-------------------| |-- NO ----| Type this command in the CONFIG.SYS file; do not enter the command at a DOS or OS/2 command prompt.

When PRIORITY_DISK_IO=YES is specified in the CONFIG.SYS file, an application running in the foreground will receive disk I/O priority over applications running in the background. This means that the application in the forground will have a better response time than applications running in the background.

PROTECTONLY

Selects one or two operating environments. PROTECTONLY ----------|------ NO ------|-------------------| |----- YES ------| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

Related Commands: ProtShell RmSize Shell

The OS/2 operating system requires this statement in the CONFIG.SYS file. The PROTECTONLY=YES statement allows memory under 640KB, which is normally used for DOS programs, to be available for OS/2 programs. When PROTECTONLY=YES, you cannot run programs in DOS sessions. If you later decide that you want to run DOS programs in the lower 640KB of memory, specify PROTECTONLY=NO. This allows you to use both DOS and OS/2 programs.

PROTSHELL

Loads the user interface program and OS/2 command processor. PROTSHELL also replaces the default OS/2 command processor, CMD.EXE, with another command processor.

PROTSHELL = --|---------|-|--------|---- filename --------- |- drive -| |- path -| . . . . . . -----------|-------------|-------------------------------| |- arguments -| Related Commands: Cmd ProtectOnly RmSize Shell

If you do not specify PROTSHELL in your CONFIG.SYS file, the default user interface for OS/2 2.0 is loaded and started with an argument of CMD.EXE.

For a system that is set up for both OS/2 and DOS sessions, the user interface is started and automatically displayed. The DOS command processor also is started but does not begin running until the DOS command prompt is selected from the Command Prompts folder.

REM

Adds comments or line spacing in a batch file or a CONFIG.SYS file. REM --------------|-----------|----------------------------| |- comment -| When adding remarks or line spacing in a batch file, it is important to note that:

The OS/2 operating system displays the remark when batch processing reaches the REM command. If ECHO is OFF, the system does not display the remarks.
You can use REM by itself to improve the readability of your batch file.

The OS/2 operating system treats the preceding REM commands as comments only and does not attempt to act on the comments.

You can use the REM command to add remarks or line spacing to your CONFIG.SYS file. Any lines of text added using REM are ignored by the system during CONFIG.SYS processing and are not displayed on your display terminal.

RMSIZE

Specifies the highest storage address allowed for the DOS operating environment.

RMSIZE = ---------------------- x --------------------------| Related Commands: ProtectOnly ProtShell Shell

If you specify a number that exceeds the amount of memory allowable for your system configuration, the system sends you an error message and ignores the statement. It then automatically calculates the largest default value for your system.

If you do not have an RMSIZE statement in your CONFIG.SYS file, the default is the total amount of low memory installed (either 512KB or 640KB).

If you decided to specify PROTECTONLY=NO, you can further reduce the size of the DOS environment by specifying RMSIZE. This allows you to make the size of the DOS environment smaller than the maximum amount available if all the remaining memory below 640KB were used for DOS sessions.

This statement specifies the highest storage address allowed for a DOS session. It is important to note that if you specify a number that exceeds the amount of memory allowable for your system configuration, the system sends you an error message. This message states that the value was not acceptable and ignores the statement. If you do not specify a RMSIZE statement in your CONFIG.SYS file, the default depends on the total memory installed. If this total is 640KB or less, then the default size is the total memory minus the minimum required for protect-mode operations. If this total is 1024KB or greater, the default size is the amount of memory installed below 1024KB, either 512KB or 640KB.

This is the largest usable size for DOS sessions at which your system can operate. If you enter a size that is too large for your system, the system displays an error message during startup and automatically calculates the largest default value possible.

RUN

Loads and starts a system program during system initialization. RUN does not start a Presentation Manager* application.

RUN = --------|---------|-|--------|---- filename --------- |- drive -| |- path -| . . . . . . -----------|-------------|-------------------------------| |- arguments -| Related Commands: Start

It is important to note that more than one RUN statement might appear in the CONFIG.SYS file. The RUN statements are processed in the order in which they appear in the file, but all DEVICE statements are processed before any RUN statements.

If a program started with a RUN statement requests a window before the user interface is started, it receives a unique error code. The program might respond by delaying its processing until the user interface is started.

A program started with a RUN statement can establish a keyboard or mouse monitor for any non-detached program. Also, it can issue I/O requests to the keyboard, mouse, or display only after it has established a window.

Because RUN programs are started before initialization of the user interface and disk error handling, the program must prevent the OS/2 operating system from performing disk handling and perform its own.

RUN - LOGDAEM.EXE

Controls the start of the Logging Daemon process for system error-log files.

RUN = --------|---------|-|--------|---- LOGDAEM.EXE --------- |- drive -| |- path -| . . . . -----------|---------------|--|--------|---------------------| |- /E:filename -| |- /W:x -| Related Commands: SysLog Device Log.Sys

A RUN=LOGDAEM.EXE command must be in the CONFIG.SYS file to control the start of the Logging Daemon process. It must be included whenever you specify the DEVICE=LOG.SYS command in the CONFIG.SYS file to install the System Logging Service device driver.

SHELL

Loads and starts the DOS command processor, COMMAND.COM, or allows you to replace the DOS command processor with another command processor.

SHELL = ------|---------|-|--------|---- filename --------- |- drive -| |- path -| . . . . . . -----------|-------------|-------------------------------| |- arguments -| Type this command in the CONFIG.SYS file; do not enter this command at a DOS command prompt.

Related Commands: Command ProtShell RmSize

If SHELL is omitted from the CONFIG.SYS file, the default DOS command processor is loaded and started with a /P parameter to retain COMMAND.COM in storage. In addition, SHELL does not affect either the OS/2 SET command, or the SHELL command in BASIC.

Also, remember that if you are using a DOS command processor other than COMMAND.COM, internal commands and the batch processor are not available to you unless they are duplicated in your command processor.

SWAPPATH

Specifies the size and location of the swap file.

SWAPPATH = drive -----|--------|--|-----------|--|-----------|-----| |- path -| |- minfree -| |- initial -| Related Commands: MemMan

The swap file (SWAPPER.DAT) is used to temporarily store data segments that the system has removed from physical memory to satisfy a request for memory. If moving and swapping are enabled, use this command to specify the location and size of the swap file.

You can isolate the swap file in either a subdirectory or a separate partition on a hard disk. A separate partition is recommended, because the swap file can become quite large.

The default location is: SWAPPATH=C:\OS2\SYSTEM The minfree parameter specifies the minimum free space that can remain on the disk before you receive a warning that the swap file has increased to a size that leaves less than this amount of free space on the disk. The initial parameter specifies the size of the swap file initially allocated by the operating system at time of installation. This value is variable and depends on the amount of physical memory in the system.

Note: The minfree value does NOT define the amount of free space on the disk at any given time because applications could cause less free space to be available on the disk than what is specified by the minfree value.

THREADS

Sets the maximum number of independent actions, known as threads, for OS/2 sessions. THREADS = --------------------- x --------------------------| Related Commands: MaxWait Priority TimeSlice

Applications consist of a series of instructions. The processor reads each instruction and performs the associated activity. The sequential execution of the instructions by the processor is called the thread of execution. More than one thread of execution can exist within a single process. Typically, OS/2 applications contain many threads.

Several threads can be ready to execute at the same time, but only one thread at a time can have access to the processor. Access to the processor is managed by the system scheduler, which assigns each thread a priority. The thread that has the highest priority, and that is ready to run, is allocated to the processor. For example, if a thread is being processed, and another thread with a higher priority becomes ready to run, the system stops processing the thread with the lower priority and allocates the processor to the thread with the higher priority. That thread will be processed until the time allocated to it (time slice) expires, or until a thread of higher priority is ready to run.

The system supports a maximum of 4095 threads, which it allocates to itself and the applications running on it. Reducing the number of threads while running complex applications or system extensions, can force activities that COULD be performed concurrently, to be performed serially, thus slowing performance. If no THREADS statement is in the CONFIG.SYS file, the default number of threads is 64.

TIMESLICE

Sets the minimum and maximum amount of processor time allocated to processes and programs for both OS/2 and DOS sessions.

TIMESLICE = --------- x ---------|------|-------------------| |- ,y -| Type this command in the CONFIG.SYS file; do not enter the command at the OS/2 command prompt.

Related Commands: MaxWait Threads Priority

Unless a dispatching priority is explicitly defined by an application, the system assigns one to each thread of execution. The system uses preemptive time slicing to ensure that threads of equal priority are given equal chances to be processed.

The first value (x) in the statement is the minimum amount of time a thread can be processed before yielding the processor to a thread of the same priority level; the second value (y) is the maximum amount of time a thread can be processed before yielding processor time.

The default is dynamic time slicing based on system load and paging activity. Dynamic time slicing gives the best performance in all situations.

TRACE

Selects or sets the tracing of system events.

This command is intended to be used with the assistance of your technical coordinator. ---|---------|-|--------|------- TRACE ------|- OFF -|----- |- drive -| |- path -| |- ON -| . . . . . .--|-----------------------|----|--|----------|---|--------| ||-- major_code_spec --|| | |--- /S ---| | ||- (minor_code_spec) -|| | |--- /R ---| | ||----- tdf_spec ------|| |------ /C -------| ||- (minor_code_spec) -|| ||- (event_type_spec) -|| ||--- tdf_keyword -----|| ||- (minor_code_spec) -|| ||- (event_type_spec) -|| |--|------ /P: -----|---| |--- pid_spec ---| To allow system trace in your CONFIG.SYS file: TRACE = ---------|- OFF -|-------------|-----|-----|-------| |- ON -| |- x -| | | | |------- , -------| Related Commands: PStat TraceBuf TraceFmt

Related Information: Trace Point Overview and Trace Definition Files (TDF)

The OS/2* operating system processes TRACE statements in the order in which they appear in the CONFIG.SYS file; the effects of the statements are cumulative. If any part of a statement is incorrect, the OS/2 operating system ignores the statement.

If you do not specify TRACE in the CONFIG.SYS file, events are not traced. However, if you have a TRACEBUF statement in CONFIG.SYS, this allocates a trace buffer. Then, you can trace events by entering the TRACE command at the OS/2 command prompt.

If TRACE=OFF or TRACE=ON appears in the CONFIG.SYS file without a TRACEBUF statement, the system allocates a 4KB trace buffer.

If you do not specify TRACE or TRACEBUF statements in the CONFIG.SYS file, OS/2 2.0 does not allocate a trace buffer and system tracing is not available.

The System Trace facility is used to record a sequence of system events, function calls, or data. The record is usually produced for debugging purposes. After the trace data is recorded, the System Trace Formatter is used to retrieve it from the system trace buffer and format the data to your display, printer, or file.

On request, the OS/2 operating system tracing facility records certain important events in the system and system extensions in a circular buffer.

If a system problem can be duplicated without a system failure, the TRACE OFF function allows tracing to be stopped after the problem has been re-created. This allows the state of the trace buffer to be preserved from the time the TRACE OFF command is processed.

The tracing mechanism is performance critical; therefore, no statistical processing of recorded data is performed by the tracing routines.

Records in the buffer are identified by major and minor codes (you can only specify TRACE by major code in the CONFIG.SYS file). Some of the data that may be recorded in the circular buffer will include system events such as interrupts and task switches.

If you need to use the System Trace facility, your technical coordinator will provide the buffer size. When the trace is complete, you can use the trace formatter (TRACEFMT) to organize the data into a report. This helps you isolate causes of problems in the OS/2 system by formatting the information placed in the trace buffer by the Trace facility.

An OS/2 enhancement to the Trace utility program allows you to trace a given process or set of processes, so that you can focus on the events of the specified process without intermixing events from other processes in the system. This reduces the possibility of trace-buffer overflow by minimizing the number of events which are recorded. Analyzing the formatted trace data is quicker and easier because only events of the specified process are recorded and displayed.

TRACEBUF

Sets the size of the trace buffer. This statement is intended to be used with the assistance of your technical coordinator. TRACEBUF= --------------------- x --------------------------| Related Commands: Trace TraceFmt

TRACEBUF sets the size of the trace buffer in the CONFIG.SYS file. If any valid TRACE statements are in CONFIG.SYS (including TRACE=OFF), the default size of the trace buffer is 4KB.

The x parameter specifies a trace buffer size of up to 63KB. If you have a TRACEBUF statement without a TRACE statement in the CONFIG.SYS file, the trace buffer size requested is specified and tracing is turned off (the same as if you specify TRACE=OFF). If you need to use the System Trace facility, your technical coordinator will provide the buffer size.

If you do not specify a TRACE or TRACEBUF statement in CONFIG.SYS file, OS/2 2.0 does not allocate a trace buffer, and system tracing is not available.