isca@icaen.uiowa.edu (Iowa Student Computer Assoc) (04/04/91)
With the nifty keyboard power switch, I found it annoying to have to
dig under my desk and power on my external HD so.... I fixed it up so
that when I power up or down my NeXTstation, my external HD does the
same. I thought others might be interested in this as it is a rather
easy hardware hack.
The way to do this is to attach a relay to the SCSI terminator power
lines on the SCSI interface. I highly suggest that you use a solid state
relay so that you don't introduce spikes on the line. (I used a Potter &
Brumfield # SSRT-120-D10 available for $15.75 from Molstad Distributing
1-800-831-0932). Attach Pin 26 of the SCSI interface to the + control
and pin 20 (GND) to the - control of the relay. Then just cut the wire
from your power switch and put the load side of the relay between them.
Finished product looks like:
++++++++++++++++++++++ SCSI Interface
Power Out --------|- 2 Load + 3 -|------------ Pin 26
(to power supply) | Relay |
Power IN ---------|- 1 Line - 4 -|------------ Pin 20
(from power switch) ++++++++++++++++++++++
-- Dave
--
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-----------------------------------------------------------------------------rgc@wam.umd.edu (Ross Garrett Cutler) (04/04/91)
In article <5244@ns-mx.uiowa.edu> isca@icaen.uiowa.edu (Iowa Student Computer Assoc) writes: > > With the nifty keyboard power switch, I found it annoying to have to >dig under my desk and power on my external HD so.... I fixed it up so >that when I power up or down my NeXTstation, my external HD does the >same. I thought others might be interested in this as it is a rather >easy hardware hack. [ hack deleted ] Nice hack. But for people who don't wan't to splice their SCSI cable, you can buy a Radio Shack surge supressor that has the following feature: it monitors one line, and if sufficient current is being drawn, it turns the other 5 lines on; otherwise, they're off. So you plug your NeXT into this special line and your drive and printer (and ...) into the others. It only cost ~ $50 and it protects your computer too. Radio Shack still has a few good products... :-) -- Please email -- I'll summarize. Ross Cutler University of Maryland, College Park Internet: rgc@wam.umd.edu
rgc@wam.umd.edu (Ross Garrett Cutler) (04/04/91)
In article <5244@ns-mx.uiowa.edu> isca@icaen.uiowa.edu (Iowa Student Computer Assoc) writes: > > With the nifty keyboard power switch, I found it annoying to have to >dig under my desk and power on my external HD so.... I fixed it up so >that when I power up or down my NeXTstation, my external HD does the >same. I thought others might be interested in this as it is a rather >easy hardware hack. [ hack deleted ] Nice hack. But for people who don't want to splice their SCSI cable, you can buy a Radio Shack surge supressor that has the following feature: it monitors one line, and if sufficient current is being drawn, it turns the other 5 lines on; otherwise, they're off. So you plug your NeXT into this special line and your drive and printer (and ...) into the others. It only cost ~ $50 and it protects your computer too. Radio Shack still has a few good products... :-) -- Please email -- I'll summarize. Ross Cutler University of Maryland, College Park Internet: rgc@wam.umd.edu