Q32499: PRINT Does Not Scroll Line 25 after a SHELL

Article: Q32499
Product(s): See article
Version(s): 4.00 4.00b
Operating System(s): MS-DOS
Keyword(s): ENDUSER | buglist4.00 buglist4.00b fixlist4.50 | mspl13_basic
Last Modified: 12-DEC-1989

The code example below does not work correctly when compiled in
QuickBASIC Versions 4.00 or 4.00b (in the environment or in an .EXE
program) or in Microsoft BASIC Compiler Versions 6.00 and 6.00b for MS
OS/2 and MS-DOS.

The first line printed after returning from a SHELL statement is
printed on line 25 and does not scroll when something else is printed
after it (i.e., the subsequent PRINT statements are printed above line
25).

Microsoft has confirmed this to be a problem in QuickBASIC Versions
4.00 and 4.00b and in Microsoft BASIC Compiler Versions 6.00 and 6.00b
for MS-DOS and OS/2 (buglist6.00, buglist6.00b). This problem was
corrected in QuickBASIC Version 4.50 and in Microsoft BASIC PDS
Version 7.00 (fixlist7.00).

The workaround is to send output to the console ("cons:") device using
the PRINT# statement, as shown below.

The following code demonstrates the problem:

PRINT "before shell"
SHELL
PRINT "after shell1"
PRINT "after shell2"
INPUT a$
PRINT a$
END

The workaround is to print to the console ("cons:") device, as in the
following program:

OPEN "cons:" FOR OUTPUT AS #1
PRINT #1, "before shell"
SHELL
PRINT #1, "after shell1"
PRINT #1, "after shell2"
INPUT a$
PRINT #1, a$
END