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Q46448: Capabilities and Limits of the /R switch on 80386 Machines

Article: Q46448
Product(s): See article
Version(s): 2.20 2.30 2.35 3.00 | 2.20 2.30 2.35 3.00
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | 386 | mspl13_basic
Last Modified: 12-APR-1990

The /R command line switch for CodeView beginning with Version 2.20 is
used only on 80386 machines. The /R switch tells CodeView to use the
four debug registers available on the 80386 chip, and also allows
hardware breakpoints. This causes CodeView to run faster when
performing debugger-intensive steps such as monitoring a tracepoint.

The /R switch works under DOS and OS/2's DOS compatibility box. It is
an unrecognized switch under OS/2. The /R switch speeds operation of
Tracepoint but not Watchpoint or Breakpoint commands.

Note: because there are only four debug registers, only four
tracepoints (of up to 4 bytes each) may be specified when utilizing
these registers. Specifying any combination of tracepoints greater
than 16 bytes will require CodeView to use software tracepoints rather
than the debug registers and all performance gains will be lost.

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