ALT+Numeric Keypad Problem When Change Code Page Command (CHCP) is Used

When you use the Change Code Page (CHCP) 437 or 850 command to change the current code page, the ALT+Numeric keypad characters are not mapped properly. This problem was initially observed in an application using the OS/2 subsystem, but it is also present in the NTVDM environment (MS-DOS mode).

Using Lucida Console fonts allows ALT+Numeric keypad characters to be entered and displayed properly according to the current code page selected by the CHCP command. This works in MS-DOS and OS/2 modes.

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.

Locale-specific code pages for U.S. versions of the Windows NT systems are defined as follows:

• OEM Primary CP (default): 437 (MS-DOS Latin US)
• OEM Secondary CP : 850 (MS-DOS Latin 1)

Locale-specific code pages for European versions of the Windows NT systems are defined as follows:

• OEM Primary CP (default): 850 (MS-DOS Latin 1)
• OEM Secondary CP : 437 (MS-DOS Latin US)

The CHCP command allows the user to change the current default code page.

Notes

• Lucida Console fonts (16-bit) must be selected in the original DOS/OS2 window in order to switch between the code pages.
• The Raster fonts (8-bit) do not allow code page switching.
• The OEM primary code page is always the default.