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From: davec@ECE.Concordia.CA (Dave Chu)
Subject: Re: More 6.270 v2.21 questions
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Date: Fri, 14 Jan 1994 01:39:39 GMT
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Thanks to all who replied to my questions.  It turned out that the
reset pin was floating.  I don't know why, it seems the
reset pin is only connected to the reset button with no pull-up
resistor attached.  I got it working by jumpering a resistor to the
reset pin, but have to get hold of the schematic to see what should
the reset circuit looks like.  According to the 6.270 v2.11 schematic
there should be a 47K pull-up resistor from RP1 connected the reset pin.
I've check on my v2.21 board and that don't seem to be the case.  

I downloaded (twice) the 6.270-1993.ps.tar file from aeneas.mit.edu 
trying to get a schematic of the reset circuit.  But there are postscript
errors in the APPENDIXA.PS file where the circuit is.  Things just can't
get any better.

I think I'll take a break for a while and work on the board again when
I'm more relax.

Dave
