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Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!ihnp4!zehntel!hplabs!sri-unix!prindle@NADC.ARPA
From: prindle@NADC.ARPA
Newsgroups: net.micro
Subject: Re: music application for the c64
Message-ID: <12553@sri-arpa.UUCP>
Date: Fri, 17-Aug-84 08:26:58 EDT
Article-I.D.: sri-arpa.12553
Posted: Fri Aug 17 08:26:58 1984
Date-Received: Mon, 20-Aug-84 01:22:01 EDT
Lines: 16


Apparently, much of the traffic on net.micro.cbm never makes it to the ARPANET,
because I never saw the original article.  But anyway, the C64 joystick trigger
button doesn't interrupt the cpu (it does toggle a line on the VIC chip which
causes the VIC chip to save the light pen raster coordinates).  Furthermore,
the joystick ports are only 5 bits each and are shared with the keyboard
scan ports (contol port 1 is 5 rows of keyboard in, control port 2 is 5 columns
of keyboard out scan), so the keyboard scan would have to be disabled in the
kernel before you could assume complete control over these ports.  I don't
know what kind of D to A conversion was required, but 5 bits only gives 32
possible analog levels.

Does anyone know why ARPANET coverage of net.micro.cbm seems so sporadic?

Frank Prindle
Prindle@NADC.ARPA