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<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007>What is it exactly that you're trying to
accomplish?</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007>The C-64 had a flat 64k address space, with no MMU and
no protection of any sort, so you could read or modify any address in
memory. Things are more complicated these days - see <A
href="http://en.wikipedia.org/wiki/Memory_protection">http://en.wikipedia.org/wiki/Memory_protection</A>.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007>If you're talking about getting access to I/O, though,
that's another matter. Easiest way to do that with no extra hardware is to
use the parallel port, if you just need a few pins. I honestly don't
remember how to do it, but there are FAQs out there. My Linux box hasn't
been powered up since I moved, so I can't look at my old code. I wrote a
small script for controlling the DR-112 radio I was using for my IGate - I just
wired the channel-up and channel-down pins of the mic connector to a couple of
transistors and connected it to the parallel port so it could automatically
change channels for PCSAT operation.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007>If you need more I/O than that, you can get commercial
data acquisition boards. I've got a 56 bit digital I/O board that I use
under Windows:</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007><A
href="http://www.icpdas.com/oldweb/products/card/pio-d56.htm">http://www.icpdas.com/oldweb/products/card/pio-d56.htm</A></SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007>I think it cost me around $120, but I really don't
remember for sure. I find it useful for testing out interface code.
For example, I wired it up to a SED1330F graphical LCD panel and prototyped all
of the code to drive it in Visual Basic.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007>I'm sure there are cheaper hobby-oriented components
out there.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007>Scott</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=478545615-28062007>N1VG</SPAN></FONT></DIV><BR>
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<FONT face=Tahoma size=2><B>From:</B> aprssig-bounces@lists.tapr.org
[mailto:aprssig-bounces@lists.tapr.org] <B>On Behalf Of </B>Andrew
Rich<BR><B>Sent:</B> Thursday, June 28, 2007 1:24 AM<BR><B>To:</B>
Aprssig<BR><B>Cc:</B> ozaprs<BR><B>Subject:</B> [aprssig] Position
mapping<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV><SPAN class=859072208-28062007><FONT face=Arial size=2>In the early days
I used to peek and poke in the commodore 64.</FONT></SPAN></DIV>
<DIV><SPAN class=859072208-28062007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=859072208-28062007><FONT face=Arial size=2>I am wondering if
something like this exists in linux ?</FONT></SPAN></DIV>
<DIV><SPAN class=859072208-28062007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=859072208-28062007><FONT face=Arial size=2>I am trying to
play with ultrasonic radars </FONT></SPAN></DIV>
<DIV><SPAN class=859072208-28062007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=859072208-28062007><FONT face=Arial size=2>Andrew
VK4TEC</FONT></SPAN></DIV></BLOCKQUOTE></BODY></HTML>