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Path: utzoo!mnetor!seismo!mcnc!ecsvax!mjg
From: mjg@ecsvax.UUCP (Michael Gingell)
Newsgroups: comp.sys.ibm.pc
Subject: Turning off the cursor on an EGA
Message-ID: <3508@ecsvax.UUCP>
Date: Wed, 8-Jul-87 08:50:06 EDT
Article-I.D.: ecsvax.3508
Posted: Wed Jul  8 08:50:06 1987
Date-Received: Sat, 11-Jul-87 03:51:30 EDT
Organization: UNC Educational Computing Service
Lines: 26
Keywords: EGA, CGA, MDA, Cursor, OFF, HELP, antidisestablishmentarianism


Does anyone know of a reliable method of turning off the cursor on
an EGA when running in CGA emulation mode ?.  With regular monochrome or
color display adapters one can address the 6845 display controller thus:

	mov	dx,3b4h	;3d4 if color
	mov	al,0ah
	out	dx,al	;selects register 10 of 6845
	inc	dx
	mov	al,20h	;set bit 5 of register 10
	out	dx,al

However, most EGAs do not contain a 6845 nor do they fully emulate one.
Also, the BIOS and DOS do not contain any official documented method of
doing this via INT calls.  I seem to remember seeing this stated for a fact
in Microsoft's Advanced MS-DOS book.  I know you can specify an illegal
location for the cursor, or specify impossible start and end cursor scan
lines but what is the effect of this on an EGA ?.

What I really want to do is to make the cursor invisible while still leaving
it at the current location. The above method works fine on regular monochrome
and color displays but will it work on EGAs ???.

Any pointers would be most gratefully accepted,

		Mike Gingell    ....decvax!mcnc!ecsvax!mjg