[coco] A couple of PC hardware questions

[peak at mail.polarcomm.com]

Ray
I have re-packed my coco3 into a case using an ATX power 
supply! There were some difficulties.
An ATX power supply has some special features because it is 
Turned on by the computer motherboard and not by the front 
powers switch on the computer. ----WHY??---
Vsb is +5volts which is always on provided that the rocker 
switch on the back of the power supply is on and the power 
cord is plugged in. (Voltage Stand By).
VSB is used by the motherboard to turn on the computers power 
supply depending on certain conditions.
One of those conditions is that the operator presses the on 
switch on the front of the computer.
Another condition is that there is a suficient load on the 
power supply.
To turn on an ATX supply try this:
Connect an old MFM hard drive to the supply.(load)
Connect the ATX "PS-ON" wire to ground.
Check to see if it turns on.
Eric


---- Original message ----
>Date: Thu, 15 Jan 2004 19:08:51 -0800
>From: Ray Watts <rayanddoraleew at earthlink.net>  
>Subject: [coco] A couple of PC hardware questions  
>To: Coco <Coco at maltedmedia.com>
>
>1.  What is the difference between an AT and an ATX power 
supply?  I 
>note that the specs for an ATX show a +5V VSB lead.  How is 
that used?
>
>2. Does a PS/2 keyboard operate identically to an AT 
keyboard (except 
>for the connector size)?
>
>The reason I ask is that the latest JAMECO catalog has a 
150W ATX PS 
>(though a litttle pricey) that will slide easily into the 
space left by 
>pulling the transformer and voltage regulator heat sink.  
This will 
>allow one to install a superboard, a SCSI controller, a 
floppy 
>controller (both on a Y-cable), a couple of 3.5" floppy 
drives, a SCSI 
>HD and an internal SCSI ZIPdrive all into a CoCo chassis.  
Then, all you 
>have to do is build a polystyrene backplane and cover.  
Essentially, 
>this is what I did on the Grizzly CoCo except I only had a 
65W PS so I 
>had to go with an external ZIP.  And, of course, Disto 2-meg 
and 3 in 1 
>boards in place of the superboard.  I was able to obtain 
several 
>internal ZIP's to use for this purpose.  One advantage to 
internal ZIP's 
>is (correct me if I'm wrong, Mark) you are not restricted to 
using /h5 
>and /h6.
>
>JAMECO also has PS/2 keyboards (also a little pricey)  in 
place of those 
>windows monstrosities flooding the market.
>
>Thanks,    Griz
>
>
>
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