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<DIV><FONT face=Arial size=2>As I sent to rasterlist a earlier
today:</FONT></DIV>
<DIV> </DIV>
<DIV>:::::::::::</DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Anyone used these together? There appears to
be some odd bank switching to the ram and I can't quite get a handle on
it. Have a board that watch dogs constantly.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>As far as I can see there is something wrong in the
DRAM address selector. Pin 8 of the LS10 @ E3 never changes. I piggy
backed another chip on it with pin 8 pulled up and it also gave the same
result. As far as I can see all the inputs to that area are correct but I
am wondering about ~IRQH which is the hardware interrupt signal. There is
a note on the schematics that this signal will disable the DRAM address
controller from setting the MADSEL.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Tracking ~IRQH back to its source it appears that
16FLIP is triggering which leads me to FLIP which is triggering. Now I
wouldn't expect FLIP to fire unless I had the cocktail strap in. Plus I am
running -01 roms which don't even support FLIP.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>As you can probably guess I am going in circles
just a bit.</FONT></DIV>
<DIV> </DIV>
<DIV>:::::::</DIV>
<DIV> </DIV>
<DIV>A bit more information, going over the sync section of the schematics I
noticed something odd, the HBLANK and 128H signals are both the same count
15.6hz. I would have thought that the HBLANK should be 1/2 the rate of
128H as it is one step further down the counter.</DIV>
<DIV> </DIV>
<DIV>And going back to FLIP, looking at the xxxV signal generation the sourcing
clock for this section appears to be FLIP. Now I am really confused.</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Ideas?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>David</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV></FONT></DIV></BODY></HTML>
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Received on Sun Nov 10 22:29:40 2002
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