[net.micro.pc] need reset button for pc clone

stevens@boulder.UUCP (Curt Stevens) (11/06/86)

I have a voodoo XT clone that sometimes has a problem with hanging the CPU
when performing a warm boot in fast mode. This forces me to spin down my
disk drive a lot more often than I like. My question (request) is whether
or not there is a piece of hardware (hopefully cheap) that will serve as
a reset button for these situations. Alternately, is there a way that I can
power the disk drive from an external source so that powering down the CPU
doesn't spin down the drive? Any help with this would be GREATLY appreciated.
(I have a Seagate 20 meg AT drive, 4025 is the number I think, and I run
an 8088-2).
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Curt Stevens                      |             ||    ---           \
University of Colorado at Boulder |             ||    | |            \
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mark@ems.UUCP (Mark H. Colburn) (11/07/86)

We have made several reset buttons for our pc's here at work.  On the IBM/PC,
I am not sure about others, there is a line going from the power supply to
the mother board called power good.  This line is used by the system to
monitor the quality of power that is being supplied.  This line is constantly
held high by the system.  If the power good line drops below a certain
threshold voltage then the system will shutdown.  Neat, huh?  So, what you
do is buy a momentary contact switch and connect one of the leads to the
power good line and the other lead goes to ground.  On the PC this can
be done without soldering, since the leads will fit quite nicely into
the power connector plug on the mother board along side the wires from
the power supply.  Now, when you press the switch you will pull the power
good line low, and the system will reset.  This is roughly equivilent to
a cold boot, without the POST.  Total cost is about $1.35.




-- 
Mark H. Colburn             UUCP: ihnp4!rosevax!ems!mark
EMS/McGraw-Hill              ATT: (612) 829-8200
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