MSHERC.COM Mistakenly Loads on CGA Computer; README Addition

This article was previously published under Q69537
This article has been archived. It is offered "as is" and will no longer be updated.
SUMMARY
MSHERC.COM is a Hercules graphics driver supplied with MicrosoftQuickBasic version 4.50 and Microsoft Basic Professional DevelopmentSystem (PDS) versions 7.00 and 7.10. QBHERC.COM is the equivalentdriver supplied with Microsoft QuickBasic versions 4.00 and 4.00b. Youmust run MSHERC.COM or QBHERC.COM before you can use Hercules graphics(SCREEN 3) in your Basic programs.

MSHERC.COM or QBHERC.COM should not load on a system that is using agraphics adapter other than Hercules. If invoked on a system using anEGA or VGA graphics card, MSHERC.COM or QBHERC.COM reports thefollowing error and does not load:
Hercules Video Card not present.
Hercules Video Support Routines not installed.
However, on some systems using CGA graphics cards, MSHERC will loadinto memory and display the following:
Hercules Video Support Routines installed.
This behavior consumes memory unnecessarily, and the message can bemisleading because Hercules graphics (SCREEN 3) does not work on CGAsystems. MSHERC.COM or QBHERC.COM should not be run on computers thathave a CGA card.

README.DOC Addition for MSHERC.COM

All documentation for the driver file MSHERC.COM was mistakenly leftout of the manuals, online Help, and README.DOC file of QuickBasicversion 4.50 and Basic PDS versions 7.00 and 7.10. MSHERC.COM isbriefly mentioned in the packing list (PACKING.LST) of these products,but instructions are missing.

The following instructions for QBHERC.COM are taken from theREADME.DOC file for QuickBasic versions 4.00/4.00b and Basic compilerversions 6.00/6.00b; this information applies to both QBHERC.COM andMSHERC.COM:
The SCREEN statement now includes mode 3 for Hercules display adapters. The following is a brief summary of screen mode 3. See your Hercules documentation for details.

QuickBasic supports Hercules Graphics Card, Graphics Card Plus, InColor Card, and 100% compatibles.

You must use a monochrome monitor.

Hercules text mode is SCREEN 0; Hercules Graphics mode is SCREEN 3.

You must load the Hercules driver (QBHERC.COM) before running your program. If the driver is not loaded, SCREEN 3 statement gives an "Illegal function call" error message. Type QBHERC to load the driver.

Text dimensions are 80x25 (9x14 character box); bottom 2 scan lines of 25th row are not visible.

Resolution is 720x348 pixels, monochrome.

Number of screen pages supported is 2.

The PALETTE statement is not supported.

In order to use the Mouse, you must follow special instructions for Hercules cards in the Microsoft Mouse Programmer's Reference Guide. (This must be ordered separately; it is not supplied with either the QuickBasic or the Mouse package.)
QuickBas BasicCom
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Article ID: 69537 - Last Review: 02/27/2014 21:01:27 - Revision: 1.2

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