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Using the DOS Requesters

This section documents the use of DOS requesters.

Overview

Pervasive.SQL V8 supports DOS Btrieve applications in several different ways. The exact method, however, depends on the current configuration and environment of the workstation.

Requesters Available

The following choices are available:

Note
DOS Box support must be used for Workgroup engines. These engines do not support the DOS requesters described below.

There are different reasons for using these different options, including:

Supported Configurations

The table below shows the DOS requester configurations that are supported.

 
Table 18-4    Supported DOS Requester Configurations
Requester
Workgroup or Server Engine on Windows 98/ME (Local application)
Workgroup or Server Engine on Windows NT/2000 (Local application)
Client on Windows 98/ME to Remote Server Engine
Client on Windows NT/2000 to Remote Server Engine
DOS Box

ü

ü

ü

ü

BREQTCP


TCP/IP only
TCP/IP only
BREQNT


SPX only
SPX only
BREQUEST


SPX to NetWare only
SPX to NetWare only

The preferred Requester for Windows is BTRBOX. You can use this Requester even for legacy DOS applications, and for Workgroup applications.

Note
Use the BREQUEST/BREQNT/BREQTCP Requesters ONLY if you experience a problem with BTRBOX. These Requesters are supported for access to Server engines only, not to Workgroup engines.

Win16 and DOS Workstations

The Requesters for non-Win32 boxes are:

The following sections document the steps for running DOS applications on Windows NT and Windows 2000, Windows 9x, and DOS.

Running DOS applications on Windows NT/2000

To run a Pervasive application on a Windows NT/2000 workstation or locally on a Windows NT/2000 server, you should always install the Windows client components. Note, these are installed on the Windows NT/2000 server by default. You can find the Windows client installation on the Pervasive.SQL V8 CD in the \clients\win directory. Typically, the client installation programs are also installed automatically on your Pervasive.SQL V8 server in the \pvsw\clients\win directory.

After the Windows client component installation, you will have everything you need to run a DOS, Windows 16-bit, or Windows 32-bit application. The default DOS application support installed is the Win32 DOS Box configuration.

Using/Disabling Win32 DOS Box Support

Under Windows NT/2000, the DOS Box Install configures the drivers to be completely transparent. Thus, you are able to immediately open a command prompt and run a DOS Btrieve application. The CONFIG.NT file, located in the WINNT\SYSTEM32 directory, contains the command that enables DOS application support. This file is similar to the old Config.SYS in DOS. Windows NT and Windows 2000 load it for each DOS session opened. In here, the Install places the following path to load the Win32 DOS Box driver: 

DEVICE = C:\PVSW\BIN\BTRDRVR.SYS

To disable the Win32 DOS box support to use the DOS TCP/IP or SPX requester, you must follow these steps:

  1. Remove the files BTRDRVR.SYS and BTRVDD.SYS from your system; these are installed by default in the \pvsw\bin directory.
  2. Edit the Config.NT file (using Notepad) in the folder WINNT\SYSTEM32. Delete or invalidate the line: 
    DEVICE=C:\PVSW\BIN\BTRDRVR.SYS

Note
Each configuration (Win32 DOS Box, DOS TCP/IP and DOS SPX Support) is mutually exclusive. You must disable the existing configuration before configuring your machine for a new configuration.

Using DOS TCP/IP Support (BREQTCP)

To use the DOS TCP/IP requester on a Windows NT or Windows 2000 workstation, you must first disable the Win32 DOS Box support as described above, and then enable the DOS TCP/IP requester configuration.

To enable BREQTCP support on Windows NT/2000, follow these steps:

  1. Copy the following six files into your %SystemRoot%\SYSTEM directory. %SystemRoot% refers to your Windows directory, typically C:\WINNT. You can determine the value for %SystemRoot% by opening a DOS box and entering the SET command. 
    BREQTCP.EXE  
BREQTCP.MSG  
JSBDOSWS.EXE  
JSBDOSWS.DLL  
MSOCKLIB.RC  
VSLDOS.INI
  2. Click Start, point to Settings and select Control Panel.
  3. Double-click the System icon and click the Environment tab.

    In Windows 2000, double-click the System icon and click the Advanced tab to get to the environment variables setting.

  4. Add the following environment variable: 
    VSL=%SystemRoot%\SYSTEM

Note
There must NOT be a trailing semicolon in this statement.

Once the DOS TCP/IP requester is setup, follow the following steps to run a DOS application:

  1. Start a DOS session.
  2. Run JSBDOSWS.EXE
  3. Load BREQTCP.EXE from the \pvsw\bin directory; this needs to be loaded in each DOS session running a Btrieve application.
  4. Run your application.

Note
The commands to load JSBDOSWS and BREQTCP can be put in your AUTOEXEC.NT file. You can load JSBDOSWS with the Load High command.

To stop a DOS application, unload the requester components by entering the command BREQTCP /u followed by JSBDOSWS /u in the DOS box before closing it.

Using DOS SPX Support (BREQUEST/BREQNT)

There are two DOS SPX Btrieve requesters:

BREQUEST exists for historical purposes before Windows NT support was available, and is still provided because it requires smaller memory than BREQNT. If you are accessing Pervasive.SQL on a NetWare server and if you are running low on DOS conventional memory, you may need to use BREQUEST. If you are accessing a Windows NT server, you must use BREQNT.

In order to use the DOS SPX requester on a Windows NT or Windows 2000 workstation, you must first disable the Win32 DOS Box support as described above; there are no special steps required to enable the DOS SPX requester configuration.

A DOS application can be run with the SPX protocol to a remote server engine by following these steps:

  1. Start a DOS session.
  2. Load BREQNT.EXE or BREQUEST.EXE from the \PVSW\BIN directory; this needs to be loaded in each DOS session running a Btrieve application.
  3. Run your application.

To stop a DOS application, unload the requester by entering the command BREQUEST /u or BREQTCP /u in the DOS box before closing it.

Running DOS applications on Windows 9X/ME

To run a Pervasive application on a Windows 9X/ME workstation, you must always install the Windows client components. These are found on the Pervasive.SQL V8 CD in the \clients\win directory.

Typically, the client installation programs are also installed on your Pervasive.SQL V8 server in the \pvsw\clients\win directory by default.

After the Windows client component installation, you will have everything you need to run a DOS, Windows 16-bit, or Windows 32-bit application. The default DOS application support installed is the Win32 DOS Box configuration.

Using/Disabling Win32 DOS Box Support on Windows 9X/ME

Note
Legacy DOS applications must use the BTRBOX configuration on Windows 9X/ME. In fact, it is the only supported configuration with the Workgroup engine. However, with client/server products, you can run DOS applications with either the BTRBOX configuration, or the legacy 16-bit DOS requesters.

If the DOS application is being run on a DOS or Windows 16-bit operating system, then the legacy 16-bit DOS requesters MUST be used. BTRBOX works on Win32 operating systems only.

Installation Instructions

To run a DOS application with the Win32 DOS Box configuration follow these steps:

  1. Start BTRBOX95:
    1. Select the BTRBOX95 icon to launch from the Start4Programs4Pervasive.SQL V84Other Utilities menu.
    2. Load from the \pvsw\bin directory. A minimized dialog appears indicating active support. You must leave this dialog running.

      Closure of this dialog will unload BTRBOX95. You will only need to run BTRBOX once -- you may have multiple DOS sessions open using a single instance of the driver.

  2. Start a DOS session.
  3. Load BDOSSTUB.EXE from the \pvsw\bin directory; this needs to be loaded in each DOS session running a Btrieve application.
  4. Run your application.

Note
You MUST reboot after the initial installation of the Windows client components in order for the Win32 DOS Box support to function. A device driver (VxD) is registered and will not load until reboot.

The proper order to stop a DOS application is as follows:

  1. Stop the DOS application.
  2. Close the DOS box.
  3. Stop BTRBOX95.

If you do not follow this order, BTRBOX95 or the database engine may not unload properly.

In situations where stopping and restarting all clients is recommended, you should perform all three steps above. Simply stopping and starting your client applications is not sufficient.

To disable the Win32 DOS box support in order to use the DOS TCP/IP or SPX requester, you must follow these steps:

  1. Remove the files BTRBOX95.EXE, BDOSSTUB.EXE, and BTRBOX95.VXD from your system; these are installed by default in the \pvsw\bin directory.
  2. Using REGEDIT, remove the following key from your registry: 
    HKEY_LOCAL_MACHINE\System\Current Control Set\ Services\VXD\BtrBox95 

    
   Each configuration (Win32 DOS Box, DOS TCP/IP and DOS SPX Support) is mutually exclusive. You must disable the existing configuration before configuring your machine for a new configuration.

Caution
Editing your registry is dangerous and can cause you to reinstall your entire computer. If you do not feel comfortable doing this, please obtain the services of a qualified technician. Pervasive can accept no responsibility for a damaged Registry.

Using DOS TCP/IP Support (BREQTCP)

To use the DOS TCP/IP requester on a Windows 9x workstation you must first disable the Win32 DOS Box support as described above, and then enable the DOS TCP/IP requester configuration using the following steps:

  1. Ensure you have the following five files in your PVSW\BIN directory. These files are installed as part of the clients\win installation. Make sure PVSW\BIN is included in your path. 
    BREQTCP.EXE 
BREQTCP.MSG 
JSBDOSWS.VXD 
MSOCKLIB.RC 
VSLDOS.INI
  2. Use a text editor such as Notepad to edit your AUTOEXEC.BAT file located in your root directory. Make sure the following line is in the file: 
    SET VSL=C:\PVSW\BIN
  3. Edit your SYSTEM.INI file with a text editor such as Notepad. SYSTEM.INI is a Windows system file that is located in your Windows directory (for example, C:\WINDOWS). In the section [386enh], ensure the following line exists 
    DEVICE=JSBDOSWS.VXD
  4. Restart Windows 9X/ME to register your changes.

Once the DOS TCP/IP requester is setup, follow these steps to run a DOS application:

  1. Start a DOS session.
  2. Load BREQTCP.EXE from the \pvsw\bin directory; this needs to be loaded in each DOS session running a Btrieve application.
  3. Run your application.

To stop a DOS application, enter the command BREQTCP /u in the DOS box to unload the requester.

Using DOS SPX Support (BREQUEST/BREQNT)

There are two DOS SPX Btrieve requesters. BREQNT.EXE is the "dual mode" requester used by a DOS application to communicate to either a Windows NT or a NetWare server. BREQUEST.EXE is a NetWare-only version of the DOS SPX requester. This exists for historical purposes before Windows NT support was available, and is still provided because it requires smaller memory than BREQNT. If you are accessing Pervasive.SQL on a NetWare server and if you are running low on DOS conventional memory, you may need to use BREQUEST. If you are accessing a Windows NT server, you must use BREQNT.

To use the DOS SPX requester on a Windows 9x workstation, you must first disable the Win32 DOS Box support as described above; there are no special steps required to enable the DOS SPX requester configuration.

A DOS application can be run with the SPX protocol to a remote server engine by following these steps:

  1. Start a DOS session.
  2. Load BREQNT.EXE or BREQUEST.EXE from the \pvsw\bin directory; this needs to be loaded in each DOS session running a Btrieve application.
  3. Run your application.

To stop a DOS application, unload the requester by entering the command BREQUEST /u or BREQTCP /u in the DOS box before closing it.

Running DOS Applications

DOS Btrieve application support on DOS workstations is only available through the DOS TCP/IP or DOS SPX requesters.

Both allow a DOS application to communicate to a Windows NT/2000 or NetWare server running the client/server version of Pervasive.SQL V8.

Using DOS TCP/IP Support (BREQTCP)

To use the DOS TCP/IP requester on a DOS or Windows workstation, you must have one of the following TCP/IP stacks:

You can enable the DOS TCP/IP requester configuration using the following steps:

  1. Copy the following files to the target directory. If you are running DOS, the target directory is the directory where you installed the Pervasive.SQL DOS client software. These files can be found in the clients\dos directory on your Pervasive.SQL V8 CD or in the PVSW\Clients\DOS directory of a Pervasive.SQL V8 server.
    • BREQTCP.EXE
    • BREQTCP.MSG
    • M3OPEN.EXE
    • MNOVLWP.EXE
    • MFTP22.EXE
    • MSOCKLIB.RC
    • VSLDOS.*
  2. Rename your VSLDOS file to VSLDOS.INI in your target directory.

If Your TCP stack is
Rename this file to VSLDOS.INI
Microsoft LAN Manager
VSLDOS.M3
Novell LAN Workplace
VSLDOS.LWP
FTP Software
VSLDOS.FTP

  1. Edit AUTOEXEC.BAT file located in the root directory. Add the following line to the file: 
    SET VSL=[jsb-location] 

    
   where [jsb-location] is the fully-qualified path of the directory where you placed the VSLDOS.INI file. For example, C:\PVSW\BIN for DOS.
  2. Restart the computer to register the AUTOEXEC.BAT changes.

Once the DOS TCP/IP requester is setup, follow these steps to run a DOS application:

  1. Make sure your TCP/IP components are loaded, as described by your TCP/IP stack provider.
  2. Run the JSB executable appropriate for your TCP stack:
    • M3OPEN.EXE (Microsoft)
    • MNOVLWP.EXE (Novell)
    • MFTP22.EXE (FTP)
  3. Load BREQTCP.EXE.
  4. Run your application.
VENDOR-SPECIFIC NOTES

MICROSOFT LAN MANAGER

  1. Ensure that the NUMSOCKETS parameter in the [SOCKETS] section of TCPUTILS.INI is set to the maximum concurrent number of connections required.
  2. SOCKETS.EXE is a Terminate and Stay Resident (TSR) program that allows applications to use the Microsoft LAN Manager TCP/IP stack. SOCKETS.EXE must be located in the same directory as the other Microsoft LAN Manager TCP/IP executable.

NOVELL LAN WORKPLACE

Using Novell's LAN Workplace for DOS with BREQTCP.EXE requires that the environment variable EXCELAN be set to the Novell base directory. For example, if you installed LAN Workplace in the C:\NET directory, do a SET EXCELAN=C:\NET prior to loading MNOVLWP.EXE and BREQTCP.EXE.

FTP SOFTWARE

  1. Ensure that you allocate enough TCP and packet buffers for your application within the FTP kernel.

e.g. 'kernel-name' -t 16 -p 20

allocates 16 TCP connections and 20 packet buffers.

  1. Once the maximum number of connections is reached, it may prove difficult to effect any connection thereafter until all, or almost all, connections have been closed. You are therefore recommended to set the maximum number of connections to a high number.

To stop a DOS application, unload the requester components by entering the command BREQTCP /u at the DOS prompt, followed by [JSB executable] /U, where [JSB executable] is either M3OPEN.EXE, MNOVLWP.EXE, or MFTP22.EXE. If running in a Windows DOS box, unload the requester components before closing the DOS box.

Using DOS SPX Support (BREQUEST/BREQNT)

There are two DOS SPX Btrieve requesters. BREQNT.EXE is the "dual mode" requester that can be used by a DOS application to communicate to either a Windows NT or a NetWare server. BREQUEST.EXE is a NetWare-only version of the DOS SPX requester. This exists for historical purposes before Windows NT support was available, and is still provided because it has a smaller memory requirement than BREQNT. If you are accessing Pervasive.SQL on a NetWare server and if you are running low on DOS conventional memory, you may need to use BREQUEST. If you are accessing a Windows NT server, you must use BREQNT.

A DOS application can be run with the SPX protocol to a remote server engine by following these steps:

  1. At a DOS prompt, load BREQNT.EXE or BREQUEST.EXE from the \pvsw\bin directory; this needs to be loaded in each DOS session running a Btrieve application in a Windows environment.
  2. Run your application.

To stop a DOS application, unload the requester by entering the command BREQUEST /u or BREQTCP /u in the DOS box before closing it.

Verifying the DOS Configuration

To verify that the install completed successfully, you need a pure DOS Btrieve application. One of the simplest application ships with the server engines. You will find BUTIL.EXE in the PVSW\Clients\DOS directory. Running this command by itself will show a list of available commands. Do this one time to ensure the copyright information says Butil for DOS, not Windows NT. You will then want to access a Btrieve file. You can use the BUTIL -STAT command to do this. If the command completes successfully, your DOS support is functioning as designed.

Try a command like this: 

BUTIL -STAT f:\pvsw\samples\sample.btr

Here, "f:" is a drive letter mapped to your server and "f:\pvsw\samples\sample.btr" is the path and filename of an existing Btrieve data file. A successful completion will return information about the data file. Otherwise, you will see a status code indicating the problem. Pervasive Technical Support can help you resolve any problems.

DOS TCP/IP Technical Information

BREQTCP.EXE is a DOS executable that runs on various DOS and Windows platforms. It is built using JSB Corporation's Virtual Socket Library (VSL). VSL implements an API based on the Berkeley 4.3 sockets standard that enables development of platform-independent and transport-independent network applications. For information about JSB Corporation, visit their site at http://www.jsb.com.

Components of the Btrieve TCP/IP Requester

System Requirements for Btrieve TCP/IP Requester

Server software requirements

You must have one of the following client operating systems:

For DOS, you must have one of the following TCP/IP stacks:

Conventional memory required to load with defaults

Accessing NetWare Servers

You must have your Pervasive.SQL server IP address configured properly on your clients for Pervasive.SQL to function. There are two ways to do this.

To configure your clients to use the server's IP address, do ONE of the following:

In Windows 9X/ME or NT:

    1. Click Start, point to Settings and select Control Panel.
    2. Select Network, TCP/IP and click Properties.
    3. Click the DNS tab.
    4. Enable DNS and enter the appropriate server information.
    5. Verify correct configuration using the TCP/IP 'ping' to ping the server by name.

In Windows 2000:

    1. Click Start, point to Settings and select Control Panel.
    2. Select Network and Dial-up Connections, and the Local Area Connection.
    3. From the component list, select TCP/IP and then click Properties.
    4. Enable DNS by selecting the corresponding button and entering the appropriate server information.
    5. Verify correct configuration using the TCP/IP 'ping' to ping the server by name.

or

Note
BREQTCP will return Btrieve status 20 if it is unable to resolve the server name into an IP address, or if the IP address is incorrect or unreachable.

Known Issues

This section contains notes on technical issues.

Multiple DOS Boxes

When running BREQTCP on Windows 9X/ME, only one DOS box is supported. Unloading BREQTCP is not sufficient to release the JSB VxD. The DOS box must be closed before another DOS box can load BREQTCP.

On Windows NT, there is no restriction on the number of DOS boxes that can be invoked.

Use of DOS Requesters on the Windows NT platform

There are some configuration requirements when you use the DOS Requester (BREQTCP, BREQNT or BREQUEST) with Windows NT.

IP Address caching in Windows 9X/ME

After adding a target IP address for a NetWare server in the local Windows 9X/ME hosts file, BREQTCP must be unloaded and reloaded.

After correcting a target IP address for a NetWare server in the local Windows 9X/ME hosts file, the Windows 9X/ME system may need to be restarted to restart the JSB VxD.

BREQTCP caches both valid and invalid IP addresses while the JSB VSL VxD caches valid IP addresses. The result is that modifications to the hosts file will not affect BREQTCP and may not affect the JSB VSL VxD depending upon prior attempts cached. This can be confusing when you are trying to modify a target IP address in the local host's file or on a DNS server.

Note
The Windows 9X/ME 'ping' utility does not exhibit this behavior, so ping may work while BREQTCP requires that Windows 9X/ME be restarted.

Diagnosing BREQTCP.EXE initialization failures

You may receive the following error message when loading BREQTCP: 

BREQTCP-10: The function InitSocketLibrary returned an error.

If you see this message, you can determine the cause by using this checklist:

Configuring the Pervasive.SQL DOS Requester

Note
There is no DOS requestor for the SQL Relational Database Engine. All database transactions on DOS must be done through the MicroKernel.

Before configuring the Pervasive.SQL DOS Requester, review this section for any information necessary to your operation. You should also read the READDOS.TXT file on the distribution media.

You must load the Pervasive.SQL DOS Requester at a workstation running DOS before that workstation can access network data files. There are three versions of the DOS Requester: BREQUEST, BREQNT, and BREQTCP.


Version

Used On
Communication Protocol Used
BREQUEST
Local area networks that use only NetWare servers. BREQUEST uses less memory than BREQNT in accessing NetWare servers.
SPX
BREQNT
Local area networks that use Windows NT (or a combination of NetWare and Windows NT). You can also use BREQNT from a DOS box from Windows NT or Windows for Workgroups. BREQNT requires that the DOS workstations accessing the file server have the following components loaded:
  • To run BREQNT from DOS or Windows, load the Microsoft Network Client for MS-DOS and Windows. You also must use the NetWare SPX protocol stack. Pervasive recommends using the ODI drivers from Novell. You do not need to run NETX.EXE or be logged on to a NetWare server if you are using a Windows NT-only LAN.
  • To run BREQNT from a DOS box in Windows for Workgroups, load the Microsoft Windows for Workgroups Network Client.
SPX
BREQTCP
Local area networks that use NetWare or Windows NT servers.
TCP/IP

The DOS Requester loads into a DOS workstation's memory as a Terminate and Stay Resident (TSR) program. You can access local as well as remote files by running a Pervasive.SQL engine on your machine.

Use of DOS Requesters on the Windows NT platform

There are some configuration requirements when you use the DOS Requester with Windows NT.

Loading the Btrieve DOS Requester

Load the DOS Requester at the workstation by entering one of the following commands: 


[path] BREQUEST [options]
[path] BRREQNT [options]
[path] BREQTCP [options]



  
  

     
path

     
The path to the directory where the DOS Requester is stored. You can omit the path name if the DOS Requester is stored on the default drive or if it is located in a directory in your search path.

  

  

     
option

     
Any of the configuration options described in Btrieve DOS Requester Options  .

For example, if the Requester is on the default drive and you want to specify a 2,048 byte data message length, enter BREQNT /D:2048.

Note
The forward slash (/) before the configuration option is the only valid character you can use. If you specify a dash (-) or a backslash (\), the Requester may load improperly.

Unloading the Btrieve DOS Requester

To unload the DOS Requester, use the /U parameter of the DOS Requester (BREQUEST, BREQNT, or BREQTCP; see Unload Requester (/U) ), or the DOS Requester utility, BREQUTIL.EXE. At the workstation where the DOS Requester is loaded, enter BREQUTIL -STOP.

To determine the version of your DOS Requester, you can enter BREQUTIL -VER.

If files have been left open (for example, when an application does not issue a Close operation for each open file, or does not issue a Reset), simply logging out of one or more servers from a workstation does not close data files or terminate the Btrieve communications connection to the server. To close data files and terminate the connection, you must unload the Btrieve requester.

Btrieve DOS Requester Options

There are several configuration options for the Btrieve DOS Requester.

NetWare Runtime Server Support (/C)

Range: /C:0 | /C:1 | /C:1,username,password

Default: /C:1

Memory Required: Not applicable

Runtime Server Support allows access to the MicroKernel running on a NetWare Server that the user is not attached to. The workstation must have a network connection to one or more servers, but not necessarily the target Btrieve server. Using this option, you can enable or disable NetWare Runtime server support.

.
/C:0
Disables NetWare Runtime Server support.
/C:1
Enables NetWare Runtime server support. The MicroKernel looks at the username for the drive (current server) on which you are presently running.
If the username is SUPERVISOR or ADMIN, the MicroKernel searches for another username in the table of usernames for the servers to which you have a network connection.
If the username is not SUPERVISOR or ADMIN, the MicroKernel searches for that username on the NetWare Runtime server. If it is not a valid username, the MicroKernel returns Status Code 94, Permission Error, at the time of the Open or Create request on the NetWare Runtime server.
/C:1, username, password

Enables NetWare Runtime server support. The MicroKernel Database Engine verifies the specified username and password for the NetWare Runtime server. The MicroKernel returns an error if the specified username is not found or the password is invalid.

username
Preferred login name on the NetWare runtime server. If you specify SUPERVISOR for the username, the MicroKernel returns status 99 at the time of the Open or Create.

password
Login password for the specified user.

Data Message Length (/D)

Range: 532 through 57,000 bytes (55,512 bytes is the upper limit for BREQNT)

Default: 4096 bytes

Memory Required: 355 bytes + data message length

This option specifies the length of the largest record (or the largest portion or chunk of a record) you want to access through the MicroKernel. (If you omit this option, the Requester uses the default value, 4096). The Requester uses this value to calculate the length of the data message buffer reserved for passing records between the MicroKernel and your applications. The requester maintains one copy of the data message buffer.

The value you enter here should not exceed the largest communication buffer size you configure for the MicroKernel through the Configuration utility since that is the maximum message that the server communication agent can receive.

Specify the data message length in bytes. For example, if the largest record your application uses is 3,000 bytes, specify the /D option as follows: 

/d:3000

Note
Specifying a higher value than you need for the /D option does not improve performance and could waste workstation memory.

DOS Session Load (/L)

Range: Not applicable

Default: Not applicable

Memory Required: Not applicable

To run a DOS-based Btrieve application in a Windows DOS box, you must have the DOS Requester loaded in each DOS session. However, if you have already loaded the DOS Requester before loading Windows, you cannot load the DOS Requester in any subsequent DOS session. Consequently, you cannot run the DOS-based Btrieve application in the DOS box.

In each Windows DOS session that will be running a Btrieve-based application, load the DOS Requester with the /L option. Doing so loads another instance of the DOS Requester that is available only to the DOS session. This operation provides the DOS session with its own copy of the DOS Requester that is available only to the DOS session, and prevents the DOS session from using the instance of the DOS Requester that you loaded before starting Windows.

Note
Versions of Btrieve for NetWare prior to 6.15 required the DOS requesters to be loaded before Windows in order to run Win16 applications. This is no longer necessary.

Receive Packet Size (/M)

Range: 532-4,096

Default: 532 (BREQUEST) or 1514 (BREQNT or BREQTCP)

Memory Required: 3 * Receive Packet Size

This option serves the same function as the Receive Packet Size setting for the NetWare Btrieve Communications Manager server setting (described in Pervasive.SQL User's Guide). It has the same range as the server parameter but has different default that is optimized for the DOS requester.

Real-Time Data Compression (/O)

Range: None

Default: No compression

Memory Required: Approximately 32 KB on the workstation and 32 KB per client on the server

In many cases (such as when implementing extended reads or huge records), this option can help reduce network traffic and increase performance by reducing the number of packets required to complete a request to the MicroKernel. This option may, however, adversely affect memory and performance due to the compress and uncompress work that must be done.

Compressing and decompressing data takes extra CPU time on both the server and client sides. Because of overhead, do not use this option with fast networks or with slow workstations for clients.

Note
This is not to be confused with Data Compression Flag. For more information on Data Compression Flag, see Advanced Operations Guide.

Number of Servers (/S)

Range: 1 through 8, or more if memory permits

Default: 8

Memory Required: 27 bytes per server

The /S option specifies the number of MicroKernel Database Engine with which the requester can simultaneously communicate.

Number of Tasks (/T)

Range: 1 through 32,000

Default: 0

Memory Required: 9 bytes per task

The /T option specifies the maximum number of workstation tasks that can access the server engine at one time using the BTRVID function. Applications that use the BTRV function are not affected by this option. For more information about whether you should set this option, refer to the documentation for your Btrieve application.

Unload Requester (/U)

Range: Not applicable

Default: Not applicable

Memory Required: Not applicable

This option unloads the Btrieve requester from memory. It performs the same function as a BREQUTIL -STOP command.

Help (/?)

The /? option lists the options that are available.

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