Problem with SCREEN 0 Paging on CGA in QB.EXE & QBX.EXE (62270)

This article was previously published under Q62270

SYMPTOMS

Paging through the active and visible pages of SCREEN 0 does not work correctly on a CGA monitor in the QBX.EXE or QB.EXE environment This problem occurs only when single-stepping through a program and setting breakpoints to view the output of the various pages. Machines equipped with EGA or VGA video adapters do not demonstrate this problem.

STATUS

Microsoft has confirmed this to be a bug in the QB.EXE environment QuickBasic version 4.50 (buglist4.50) and in the QBX.EXE environment of Microsoft Basic Professional Development System (PDS) versions 7.00 and 7.10. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

This problem does not occur in QuickBasic versions 4.00 and 4.00b.

MORE INFORMATION

The following code example demonstrates the problem in QB.EXE or QBX.EXE. Step through the program using the F8 key. After the PRINT statement, press the F4 function key to view the output screen. The screen will not be updated on a CGA monitor.

Code Example

   DEFINT A-Z
   DO UNTIL INKEY$ <> ""
      SCREEN 0, 0, x, x
      CLS
      PRINT "SCREEN MODE 0, PAGE"; x
      x = x + 1          ' Press F4 key to view the output screen
      IF x = 8 THEN x = 0
   LOOP

Modification Type:	Minor	Last Reviewed:	1/9/2003
Keywords:	KB62270