Using CodeView /2, Hercules Graphics Cards and Libraries (46949)
The information in this article applies to:
- Microsoft CodeView for MS-DOS 2.2
- Microsoft CodeView for MS-DOS 3.0
- Microsoft CodeView for MS-DOS 3.11
- Microsoft CodeView for MS-DOS 3.14
- Microsoft CodeView for MS-DOS 4.0
- Microsoft CodeView for MS-DOS 4.01
- Microsoft CodeView for MS-DOS 4.05
- Microsoft CodeView for MS-DOS 4.1
- Microsoft CodeView for Windows 3.0
- Microsoft CodeView for Windows 3.05
- Microsoft CodeView for Windows 3.06
- Microsoft CodeView for Windows 3.07
- Microsoft CodeView for Windows 4.0
- Microsoft CodeView for Windows 4.01
- Microsoft CodeView for Windows 4.1
This article was previously published under Q46949 SUMMARY
Using CodeView in the dual-monitor mode with a Hercules graphics card
as the primary (application) monitor requires the Hercules card to be
configured in the half mode. Using the Hercules graphics library, the
monitor must be configured using the config(0) function call. This
function call is a part of the Hercules graphics library and does not
use Microsoft graphics library or the MSHERC.COM program. Therefore,
this information applies only if you are using the Hercules graphics
libraries. This is NOT the same as using the /h switch with MSHERC.
MORE INFORMATION
The first page of the Hercules graphics display card is mapped to
memory location B0000 (same as MDA), and the second page is mapped to
B8000. The CGA/EGA/VGA also use B8000 as the beginning of their video
memory. CodeView uses these two different address to run in the dual-
monitor mode, sending the application output to the primary address,
usually located at B8000, and the CodeView information to the
secondary monitor, usually located at B0000.
This works well until a Hercules graphics card is used as the primary
monitor (in graphics mode) and the CGA/EGA/VGA card is used as the
secondary monitor. The Hercules graphics card uses both pages (one at
B0000 and the other at B8000) in the full mode. Therefore, use
config(0) and only the first page (B0000) will be used and CodeView
will function properly in dual-monitor mode.
| Modification Type: | Major | Last Reviewed: | 10/23/2003 |
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| Keywords: | kb16bitonly KB46949 |
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