Q66513: Memory Requirements for Real-Mode CodeView (CV.EXE)
Article: Q66513 Product(s): See article Version(s): 3.00 3.10 3.11 | 3.00 3.10 3.11 Operating System(s): MS-DOS | OS/2 Keyword(s): ENDUSER | | mspl13_basic Last Modified: 11-NOV-1990 Real-mode versions of CodeView (CV) beginning with version 3.00 offer a number of ways to utilize available memory in order to make the greatest amount of conventional memory available to the program being debugged. The amount of memory actually used depends on the command-line options specified as well as the configuration of the system used for debugging. The following table shows the size of CodeView in standard DOS memory with each of the memory-specific command-line options (see the "More Information" section below for further details): Option RAM Usage Option RAM Usage ------ --------- ------ --------- /X 16K /D16 210K /E 192K /D32 225K /D 256K (same as /D64) /D128 320K The following descriptions of the three memory-related CodeView options explain the ways in which each option affects memory utilization in addition to the respective amounts of conventional memory that CodeView requires with each. (This information pertains only to CodeView versions 3.00 and later -- versions of CodeView earlier than 3.00 require approximately 230K of RAM specifically for CodeView.) /X - Specifies that CodeView should utilize extended memory. Assuming that enough extended memory is available, this option moves both the symbolic information and most of CV itself into extended memory. Allowing CV to be loaded into high memory requires that approximately 16K to 19K of "control" code remain in conventional memory, thus all free conventional RAM over 19K is available to load the program to be debugged (the "debuggee"). /E - Specifies that CodeView should utilize expanded memory. Assuming that enough expanded memory is available, this option moves both the symbolic information and CodeView's own overlays into expanded memory. The size of the CV "root" without the extra overlayed code is approximately 192K. Since the overlays do not cause any additional overhead with /E, all free conventional RAM over 192K is available to load the debuggee. /D - Specifies that CodeView should utilize disk overlays in conventional memory. By default, this option creates a 64K buffer area for loading disk overlays. With the 192K root, the 64K buffer means CV will take about 256K of conventional memory with /D. In addition, the symbolic information must also be loaded into conventional memory; therefore, since symbolic data varies with each program, it is not possible to specify the amount of memory available for the debuggee alone. The /D option can also be specified with a value that indicates the size of the overlay buffer area. This parameter can be any value from 16 to 128, which represents an overlay buffer size from 16K to 128K. Specifying /D16 will minimize CodeView's size with disk overlays to approximately 210K. This maximizes the amount of conventional memory that will be available to load the debuggee and the symbolic information. At the other extreme, /D128 causes CV to use approximately 320K of conventional RAM. This provides faster CodeView execution speed, but it will only work with smaller debuggees. Note: CodeView will default to the best memory usage possible. In other words, if NO memory usage option is specified, CV will try to use extended memory. If extended memory is unavailable, CV looks for expanded memory. CV will use disk overlays on its own only if expanded memory is not found.
THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.
Copyright Microsoft Corporation 1986-2002.