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From: mdvries@cwi.nl (Michiel de Vries)
Newsgroups: comp.sys.ibm.pc
Subject: Problem: IBM-Logo & EGA don't go
Message-ID: <533@turing.cwi.nl>
Date: 28 Jun 89 15:57:19 GMT
Reply-To: mdvries@cwi.nl (Michiel de Vries)
Organization: CWI, Amsterdam
Lines: 18

IBM-Logo doesn't work with an EGA card, even if you set the switches
for CGA emulation.

The problem is in so called `Mixed Mode', where there are 4 lines of text 
displayed on the graphics screen. Scrolling these lines, sometimes leaves
some pixels set; a kind of shadow of the just scrolled away lines.
Just for completeness: the text lines have to be in 40 char. mode.

The problem is known to the Dutch Logo Users Group, but they don't know
of a solution. There is no problem with a CGA card.

Questions:
- Does someone has a solution/patch for the problem?
- What causes the problem? Is it incompatibility between CGA & EGA, and does
Logo write directly to the EGA memory? Is it do-able to try to patch Logo?
What should I start to look for?

Any help will be appreciated. Thanks.