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From: oml%lanl@sri-unix.UUCP
Newsgroups: net.micro.pc
Subject: PCJr Horizontal Retrace Query
Message-ID: <349@sri-arpa.UUCP>
Date: Fri, 27-Apr-84 06:58:13 EDT
Article-I.D.: sri-arpa.349
Posted: Fri Apr 27 06:58:13 1984
Date-Received: Sat, 12-May-84 09:29:22 EDT
Lines: 14

From:  Olaf Lubeck C-3 <oml@lanl>

I've been working with the pc-jr's graphics and need to change color
registers at a particular scan line. I know that there is no
capability to interrupt at horizontal retrace but I can use the timer
interrupt to interrupt just before the retrace period.  If I could
then poll the horizontal retrace active bit, I would be able to change
color registers during that time. Only problem is I can't find
documentation to tell me if there is such a thing as a horizontal
retrace active bit.  Anyone know ...  or have other ideas?  I know the
pc had this bit.

                              Olaf Lubeck Home 505-662-3471 
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