Information on SYSTEM.INI [386enh] Entry SystemROMBreakPoint=

 Last reviewed: August 1, 1995
Article ID: Q71264
The information in this article applies to:
  • Microsoft Windows operating system versions 3.0, 3.0a, 3.1, 3.11

SUMMARY

The following is information about the SYSTEM.INI [386Enh] entry SystemROMBreakPoint=.

The first section is taken from the Windows SYSINI3.TXT file. Below that, you find more specific information on Windows' relationship with SystemROMBreakPoint=.

MORE INFORMATION

SYSINI3.TXT

SystemROMBreakPoint=<Boolean>

Default: True Purpose: Specifies whether Windows should use ROM address 

         space between F000:0000 and 1 MB for a break
         point. Windows in 386 enhanced mode normally
         searches this space to find a special instruction
         that is used as a system break point. If this
         address space contains something other than
         permanently available ROM, you should disable
         this setting.
To change: Use Notepad to edit the SYSTEM.INI file.

Windows is searching for a byte value equal to 63H, which is an adjust-requested privilege level (ARPL) instruction in the range F000-FFFF.

When the SystemROMBreakPoint variable is set to false, enhanced mode Windows allocates a one-byte block of global virtual 8086 memory in low MS-DOS conventional memory and writes a 63h in it.

With QEMM and 386Max, SystemROMBreakPoint= must be set to false. These expanded memory emulators remap the ROM. The search in the system ROM for the system ROM break point must be disabled if the ROM is going to be remapped.

KBCategory: kbref kbenv
KBSubcategory: win30 win31
Additional reference words: 3.00 3.00a 3.10 3.11 winmem

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Last reviewed: August 1, 1995
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