OPEN SCRN: or CONS: Wrong Output in QBX.EXE When Step (F8) (67378)

This article was previously published under Q67378

SYMPTOMS

When you single step (F8) through a program that redirects screen output to the device name CON or the MS-DOS standard devices SCRN: or CONS:, the output will incorrectly flash momentarily on the QBX.EXE programming environment instead of going to the output window.

STATUS

Microsoft has confirmed this to be a bug in the editing environment (QBX.EXE) of Microsoft Basic Professional Development System (PDS) versions 7.0 and 7.1. This problem does not occur in the Microsoft QuickBasic environment (QB.EXE) shipped with QuickBasic versions 4.0, 4.0b, and 4.5. Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The following short program demonstrates the problem:

OPEN "SCRN:" FOR OUTPUT AS #1   ' "CONS:" and "CON" also show problem.
FOR i = 1 TO 10
        PRINT #1, i
NEXT i

Single step through this program in the QBX.EXE 7.0 or 7.1 environment by repeatedly pressing the F8 key. The output will momentarily flash on the environment screen; no text will be displayed on the output screen. Note that just running the program (F5) will correctly print to the output screen.

Modification Type:	Minor	Last Reviewed:	1/8/2003
Keywords:	KB67378