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Q40632: If PRINT Fails on Non-Standard System, PRINT#n to "CONS:"

Article: Q40632
Product(s): See article
Version(s): 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom SR# S890112-74 | mspl13_basic
Last Modified: 12-DEC-1989

The PRINT and WRITE statements write directly to video memory; they do
not write to the screen through function calls to MS-DOS or the ROM
BIOS. This information applies to Microsoft QuickBASIC Versions 4.00,
4.00b, and 4.50, Microsoft BASIC Compiler Versions 6.00 and 6.00b for
MS-DOS and MS OS/2, and Microsoft BASIC PDS Version 7.00 for MS-DOS
and MS OS/2.

By circumventing MS-DOS and the ROM BIOS, the PRINT and WRITE
statements may not work correctly with certain non-standard or
unsupported operating-system configurations (such as PC-MOS,
Multi-DOS, or multitasking packages added to MS-DOS).

To be more compatible with non-standard systems, you can send output
to a logical device name that routes the characters through an
MS-DOS character device driver.

For example, output through the "CONS:" (CONSole) or "CON" device name
forces all output through the MS-DOS console device driver. The MS-DOS
console device driver makes ROM BIOS calls to perform the output.

You can OPEN "CONS:" FOR OUTPUT AS #n and send output with the PRINT#n
or WRITE#n statement.

Similarly, if you have trouble printing with LPRINT to a network
printer, OPEN "LPT1:" FOR OUTPUT AS #n and send output with the
PRINT#n or WRITE#n statement.

Some computer manufacturers provide an ANSI.SYS device driver on their
DOS disk. Limited graphics control may be performed through ANSI
control codes. For more information about ANSI codes, query on the
following words:

   PRINT# MS-DOS "CON" Device ANSI Escape Codes

The following device names supported by the OPEN statement are
discussed on Pages 293 and 294 of the "Microsoft QuickBASIC Version
4.0: BASIC Language Reference" manual for Versions 4.00 and 4.00b:

   "CONS:"
   "KYBD:"
   "SCRN:"
   "COM1:", "COM2:"
   "LPT1:", "LPT2:"

The following is a code example:

CLS
OPEN "CONS:" FOR OUTPUT AS #1
PRINT #1, "Howdy pahd-nuh..."
CLOSE #1
END

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