Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!tektronix!percival!bucket!leonard
From: leonard@bucket.UUCP (Leonard Erickson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Cursor question, Int 0x10 service 0x03
Keywords: insert cursor, problem, certain machines
Message-ID: <1152@bucket.UUCP>
Date: 27 Nov 88 19:45:39 GMT
References: <9821@watdragon.waterloo.edu>
Reply-To: leonard@bucket.UUCP (Leonard Erickson)
Distribution: comp
Organization: Rick's Home Grown Unix; Portland, OR
Lines: 35

In article <9821@watdragon.waterloo.edu> bamcpherson@trillium.waterloo.edu (Brent McPherson) writes:
<	I calculate a half-height insert cursor from the information
<	received through interrupt 0x10, service 0x03. 
<	What I do is take the old cursors bottom scan line, divide this
<	by two. This now becomes the new top scan line of the insert cursor.
<
<	eg.
<
<	regs.h.ah = 0x03;                /* read cursor position */
<	intr( 0x10, ®s );             /* perform video interrupt */
<	old_cursor = regs.x.cx;          /* save normal cursor */
<	ins_cursor = (((old_cursor & 0xff) >> 1) << 8) + (old_cursor & 0xff);
<
<
<	The cursor is set by using interrupt 0x10, service 0x01 and
<	the cursor (old or ins) is stored into CX.
<
<	There seems to a problem on certain machines. (the plain IBM PC
<	with a monochrome monitor I think) Basically instead of getting a
<	half-height insert cursor you get a cursor in the middle of the
<	character. Also a mode change using "mode" seems to correct the 
<	problem.

The problem is that on IBM monochrome cards, Hercules cards or on clones of
either, the system 'sees' "monochrome". For god only knows what reason,
monochrome displays do not return the corect values from BIOS call. Sometimes
you will get the correct values, most of the time you won't. 

The only "solution" I know of is to test for monochrome, and then *assume*
the standard cursor.... then modiify/restore accordingly.      
-- 
Leonard Erickson		...!tektronix!reed!percival!bucket!leonard
CIS: [70465,203]
"I used to be a hacker. Now I'm a 'microcomputer specialist'.
You know... I'd rather be a hacker."