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 The BLINKER environment variable
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 At program start up the Blinker kernel checks the DOS environment for the
 BLINKER environment variable, which allows certain Blinker settings to be
 overridden at program run time. The name of this environment variable can be
 changed at link time with the BLINKER ENVIRONMENT NAME command. For more
 details refer to the BLINKER ENVIRONMENT NAME section of the online help.in
 Chapter 9. If the environment variable name is present, the variable is
 examined for the following settings:

 /CEnnn,nn   Amount of EMS to use for overlay cache
 /CXnnn,nn   Amount of XMS to use for overlay cache
 /DHn        Debug Handle
 /DI3        Debug Interrupt 3
 /DTnnnn     Dual Mode threshold in KB
 /EBnnnn     Extended memory block size in KB
 /ED-        Disable extender debugging
 /ED+        Enable extender debugging
 /EInnn      Extender IPX buffers count
 /EK-        Disable extender special keyboard handling
 /EK+        Enable extender special keyboard handling
 /ELnnnn     Extended memory limit in KB
 /ETnnnn     Extended Mode threshold in KB
 /HD-        Disable DPMI host support
 /HD+        Enable DPMI host support
 /HM-        Disable display of host messages
 /HM+        Enable display of host messages
 /HP-        Disable host passup of IRQ interrupts
 /HP+        Enable host passup of IRQ interrupts
 /HQ-        Disable QDPMI host support
 /HQ+        Enable QDPMI host support
 /HV-        Disable VCPI host support
 /HV+        Enable VCPI host support
 /HX-        Disable XMS host support
 /HX+        Enable XMS host support
 /LRnn       Reserve memory < 1 Mb for program use
 /OOnn       Overlay pool Operating size in KB
 /OP-        Disable use of EMS pageframe for overlays
 /OP+        Enable use of EMS pageframe for overlays
 /OU-        Disable use of XMS UMBs for overlays
 /OU+        Enable use of XMS UMBs for overlays
 /SD<path>   Directory for SWPRUNCMD() swap file
 /SE-        Disable use of EMS by SWPRUNCMD()
 /SE+        Enable use of EMS by SWPRUNCMD()
 /SU-        Disable use of UMBs by SWPRUNCMD()
 /SU+        Enable use of UMBs by SWPRUNCMD()
 /SX-        Disable use of XMS by SWPRUNCMD()
 /SX+        Enable use of XMS by SWPRUNCMD()
 /WS-        Disable detection of SoftICE/W
 /WS+        Enable detection of SoftICE/W

 The /CEnnn,nn setting is an override of the link time command BLINKER CACHE
 EMS nnn which controls the amount of EMS memory used by the overlay manager
 for overlay caching. For details of the usage of these values, see the
 command BLINKER CACHE EMS in the online help.

 The /CXnnn,nn setting is an override of the link time command BLINKER CACHE
 XMS nnn which controls the amount of XMS memory used by the overlay manager
 for overlay caching. For details of the usage of these values, see the
 command BLINKER CACHE XMS in the online help.

 The /DHn setting is an override of the link time Blinker command BLINKER
 DEBUG HANDLE n which controls the handle of the destination of debug output
 from Blinker. For details of the usage of this value, see the command
 BLINKER DEBUG HANDLE in the online help.

 The /DI3 setting enables the creation of a debug interrupt 3 instruction
 just before the Blinker kernel jumps to the first line of the main program.
 This setting should only be used while debugging. For more details see the
 debugging sections in the online help.

 The /DTnnnn setting is an override of the link time Blinker command BLINKER
 EXECUTABLE DUAL nnnn which controls whether a dual mode program runs in real
 or protected mode. This can also be used during testing to force the program
 to run in real mode by setting /DT20000 (or some suitably large figure). For
 details of the usage of this value, see the command BLINKER EXECUTABLE DUAL
 in the online help.

 The /EBnnnn setting is an override of the link time BLINKER EXTMEM BLOCK
 command, which is used to control the Blinker extender's memory allocation
 block size. For further details, see the BLINKER EXTMEM BLOCK command in the
 online help.

 The /EDc setting (where c=- is disabled and c=+ is enabled) controls the
 debugging mode of the Blinker extender. These settings enable and disable
 certain debugging messages provided by the extender, such as checking for
 aliasing of segments which are not locked or not present, and freeing of
 selectors using a free memory function call. It is advisable to test your
 programs running under a VCPI or XMS host (ie not DPMI) with this option
 enabled to check for these circumstances. The default is disabled.

 The /EInnn setting specifies the number of IPX ECB buffers allocated by the
 extender's IPX module. The default value is 32. For details, see the BLINKER
 EXECUTABLE IPX command in the online help.

 The /EKc setting (where c=- is disabled and c=+ is enabled) controls the
 keyboard handling of the Blinker extender. These settings enable and disable
 special handling of certain keyboard BIOS calls by the extender to prevent
 needless mode switching. When enabled, this option can increase the
 performance of serial communications routines. When disabled, this option
 may improve compatability with old TSRs which manipulate the keyboard. The
 default is disabled.

 The /ELnnnn setting is an override of the link time BLINKER EXTMEM LIMIT
 nnnn command, which is used to control the total amount of extended memory
 allocated by the Blinker extender. For details, see the BLINKER EXTMEM LIMIT
 command in the online help.

 The /ETnnnn setting is an override of the link time BLINKER EXECUTABLE
 EXTENDED nnnn command, which is used to control whether an extended mode
 program is able to run in the memory available. For details, see the BLINKER
 EXECUTABLE EXTENDED command in the online help.

 The /HDc setting (where c=- is disabled and c=+ is enabled) is an override
 of the link time BLINKER HOST DPMI command, which controls the usage of a
 DPMI host by the Blinker extender. For further details, see the BLINKER HOST
 DPMI command in the online help.

 The /HMc setting (where c=- is disabled and c=+ is enabled) is an override
 of the link time BLINKER HOST MESSAGES command, which controls the display
 of host messages by the Blinker extender. For further details, see the
 BLINKER HOST MESSAGES command in the online help.

 The /HPc setting (where c=- is disabled and c=+ is enabled) is an override
 of the link time BLINKER HOST PASSUP command, which controls the automatic
 pass up of IRQ interrupts from real mode to protected mode by the Blinker
 extender. This setting should only be necessary for debugging purposes when
 testing interrupt handlers, and is enabled by default. For further details,
 see the BLINKER HOST PASSUP command in the online help.

 The /HQc setting (where c=- is disabled and c=+ is enabled) is an override
 of the link time BLINKER HOST QDPMI command, which controls the usage of a
 QDPMI host by the Blinker extender. For further details, see the BLINKER
 HOST QDPMI command in the online help.

 The /HVc setting (where c=- is disabled and c=+ is enabled) is an override
 of the link time BLINKER HOST VCPI command, which controls the usage of a
 VCPI host by the Blinker extender. For further details, see the BLINKER HOST
 VCPI command in the online help.

 The /HXc setting (where c=- is disabled and c=+ is enabled) is an override
 of the link time BLINKER HOST XMS command, which controls the usage of an
 XMS host by the Blinker extender. For further details, see the BLINKER HOST
 XMS command in the online help.

 The /LRnnn setting is an override of the link time Blinker command BLINKER
 LOWMEM RESERVE nnn which controls the amount of conventional memoy reserved
 for program use, preventing Blinker's DOS extender from using it for other
 purposes. For further details,details of the usage of this value, see the
 command BLINKER LOWMEM RESERVE in the online help.

 The /OOnn setting is an override of the link time Blinker command BLINKER
 OVERLAY OPSIZE nn which controls the operating size of the Blinker overlay
 pool. For details of the usage of this value, see the command BLINKER
 OVERLAY OPSIZE in the online help.

 The /OPc setting (where c=- is disabled, and c=+ is enabled) is an override
 of the link time Blinker command BLINKER OVERLAY PAGEFRAME which controls
 the allocation of the overlay pool using the EMS (3.2+) pageframe. For
 details of the usage of this value, see the command BLINKER OVERLAY
 PAGEFRAME in the online help.

 The /OUc setting (where c=- is disabled, and c=+ is enabled) is an override
 of the link time Blinker command BLINKER OVERLAY UMB which controls the
 allocation of the overlay pool using XMS 2.0 upper memory blocks. For
 details of the usage of this value, see the command BLINKER OVERLAY UMB in
 the online help.

 Note: the Blinker overlay manager obtains control before the program begins
 execution, so the system resources controlled by the previous settings are
 allocated before the main program gets control.
 The BLINKER environment variable may also be used to alter the behaviour of
 Blinker's built in swap function (SWPRUNCMD()), using the following
 settings:

 The /SD<path> setting may be used to specify a directory path to be used by
 SWPRUNCMD() when saving the parent program's image to disk. This setting is
 an override of the `temporary directory' parameter passed to SWPRUNCMD()
 itself. For further details, see the function SWPRUNCMD() in the online
 help.

 The /SEc setting (where c=- is disabled, and c=+ is enabled) is an override
 of the swap function SWPUSEEMS(), which controls the usage of EMS memory by
 SWPRUNCMD() for saving the parent program's memory image. For further
 details, see the function SWPUSEEMS() in the online help.

 The /SUc setting (where c=- is disabled, and c=+ is enabled) is an override
 of the swap function SWPUSEUMB(), which controls the usage of UMBs by
 SWPRUNCMD() for relocating the resident portion of the swap function's
 kernel. For further details, see the function SWPUSEUMB() in the online
 help.

 The /SXc setting (where c=- is disabled, and c=+ is enabled) is an override
 of the swap function SWPUSEXMS(), which controls the usage of XMS memory by
 SWPRUNCMD() for saving the parent program's memory image. For further
 details, see the function SWPUSEXMS() in the online help.

 The /WSc setting (where c=- is disabled, and c=+ is enabled) enables or
 disables checking for the presence of the NuMega SoftICE/W debugger in
 protected mode running in a DOS box of Windows. This setting is enabled by
 default. For further details, see the section entitled `NuMega SoftICE/W
 debugger' in the `Special features' chapter of the manual and online help.

 The BLINKER environment variable can be used to alter settings quickly while
 testing an application, and to provide unique settings for individual
 workstations once the application is in production.
 Settings in the BLINKER environment variable should be separated by spaces,
 ie:

 SET BLINKER=/HM+ /ET2000

 This example enables the display of host messages by the Blinker extender
 and sets the extended memory threshold to 2000 Kb.

 The default environment variable name `BLINKER' can be changed with the use
 of the command BLINKER ENVIRONMENT NAME, which will avoid conflict with
 other Blinker linked programs that are present on the same computer.

 For example, you could change the name to `MYAPP', causing Blinker to ignore
 the `BLINKER' variable, and use `MYAPP' instead:

 SET MYAPP=/OP- /OO30 /CX128