[comp.sys.ibm.pc] A hardware reset switch for the AT and compatibles

tr@thumper.UUCP (03/02/87)

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Thanks to those who described how to build such a switch for
8088-based machines on behalf of those who use them.  How about one
for '286 machines?  Is the technique the same?
-- 
Tom Reingold
tr@bellcore.com

johnl@ima.UUCP (03/03/87)

In article <429@thumper.UUCP> tr@thumper.UUCP (Tom Reingold) writes:
>Thanks to those who described how to build such a switch for
>8088-based machines on behalf of those who use them.  How about one
>for '286 machines?  Is the technique the same?

I built one for about five bucks.  The AT has a "power good" signal
coming out of the power supply; if you pull that signal down to ground
for a moment the AT will think that it's just been turned on and reboot.
I put a momentary contact switch in series with a 220 ohm resistor (I picked
220 just because I had one lying around and didn't want to short the +5
directly to ground.)  Power good is pin 1 on the PS8 power connector and
a convenient ground is pin 6 on the same connector.  I just folded over the
leads from my switch and stuffed them into the back of PS8 to avoid any
cutting or soldering.  Works great.
-- 
John R. Levine, Javelin Software Corp., Cambridge MA +1 617 494 1400
{ ihnp4 | decvax | cbosgd | harvard | yale }!ima!johnl, Levine@YALE.something
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