Support for IBM EGA and Hercules Graphics Cards (21839)

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EGA Support

QuickBasic versions 2.0, 2.01, 3.0, 4.0, 4.0b, and 4.5 support EGA through the use of SCREEN modes 7, 8, 9, and 10. QuickBasic versions 1.0, 1.01, and 1.02 do not support the EGA. The 43-line EGA mode is supported in the Editor and in the WIDTH statement in QuickBasic versions 3.0, 4.0, 4.0b, and 4.5. The EGA is also supported in OS/2 real mode and MS-DOS for programs compiled with Microsoft Basic Compiler versions 6.0 and 6.0b for MS-DOS and MS OS/2, and Microsoft Basic Professional Development System (PDS) version 7.0. The EGA is not currently supported for Basic programs that run in OS/2 protected mode.

Hercules Support

Microsoft QuickBasic versions 4.0 and later, Microsoft Basic Compiler versions 6.0 and 6.0b, and Microsoft Basic PDS versions 7.0 and 7.1 all support the Hercules Monochrome Graphics Card, Hercules Graphics Card Plus, Hercules InColor Card, and cards that are 100 percent compatible with these cards. The following describes how Hercules cards are supported in QuickBasic:

• Hercules graphics mode is SCREEN 3.
• Hercules text mode is SCREEN 0.
• With Hercules, you must use a monochrome monitor.
• You must load the Hercules driver (MSHERC.COM in QuickBasic 4.50 and in Basic PDS 7.0 and 7.1; QBHERC.COM in QuickBasic 4.0, 4.0b, and in Basic Compiler 6.0 and 6.0b) before running your program. If the driver is not loaded, the SCREEN 3 statement gives an "Illegal function call" error message. Type MSHERC (or QBHERC in earlier versions) to load the driver.
• The text dimensions are 80x25 (9x14 character box); the bottom two scan lines of the 25th row are not visible.
• The resolution is 720x348 pixels, monochrome.
• SCREEN 3 supports two pages (0 and 1); SCREEN 0 used with Hercules supports only one page.
• The PALETTE statement is not supported.
• To make function calls to the Microsoft Mouse, you must follow special instructions for Hercules cards in the "Microsoft Mouse Programmer's Reference Guide." (This manual must be ordered separately; it is not supplied with either the QuickBasic or the Microsoft Mouse packages.)

The use of Hercules cards is also documented in the README.DOC file on the QuickBasic versions 4.0, 4.0b, and 4.5 release disk, which supplements the Microsoft QuickBasic documentation.