[rescue] Perverse Question

[Curtis H. Wilbar Jr.]

>From what I know of all this, as long as you have the voltages you
need at sufficient currents, you can use an IPC/IPX supply to power
anything you want.

The power switch on modern PCs simply feeds a signal to the ATX/similar
power supply to tell it to turn on or turn off.  If you provide power
to the pins on the PC mainboard, it should just "turn on".

Big question is modern PCs require 3.3V ... without looking stuff up,
I can't recall if the IPC/IPX supply provides 3.3V.

-- Curt

>Date: Sat, 7 Jun 2003 10:55:27 -0700 (PDT)
>From: Robert Novak <rnovak at indyramp.com>
>To: Al Potter <apotter at spankingnuns.com>, The Rescue List <rescue at sunhelp.org>
>Subject: Re: [rescue] Perverse Question 
>Cc: 
>
>On Sat, 7 Jun 2003, Al Potter wrote:
>
>> Gawd, I love stiring up a hot topic....    8-)
>
>Heh. No goth babes to rile here, but...
>
>> I guess what would be ideal, if there was such a beast, would be a
>> replacement mainboard of IPX/IPC size, with compatible power connectors,
>> but with mini-itx guts.
>
>Agreed. If something of similar size and power capability were available
>in MIPS or AXP processors, it'd have more cool points and (at least for
>AXP) similar 'puting power for the space and power used.
>
>Maybe some of the people who want you dead for wanting to use a good case
>will send you some free Cycle upgrade boards for these critters. :) There
>were Cycle 5-IP boards that would take you as high as 125mhz MicroSPARC.
>
>> Now, back to the real question, which was would the IPX/IPC power supply
>> be convertible to feed a mini-ipx board through an ATX connector. I had
>> not considered the power-on issue. How does that work with a "proper"
>> atx supply?  Is it never totally off or something?
>
>I believe it is never totally off whilst plugged into mains. Most of these
>boards have a LED on the board that is on when power is fed to the PS,
>even if the PS is "off." There's a low amount of voltage fed through the
>board, enough to do something if the momentary-contact power switch is
>"closed." And I believe this is the case with any system that can be
>powered up through any means other than a physical two-position on/off
>switch.
>
>Note that this is probably also the case with many Sun systems which are
>capable of powering up via keyboard. I just thought of this. I can't
>remember if the IPX and IPC and ilk work with keyboard-initiated powerup,
>as I haven't used a keyboard on one in years, but if so, the capability
>*might* be there. 10s can be soft-powered-off from the prom if there is a
>supported keyboard connected, as I recall... Tatung 5s and 20s should be
>the same way.
>
>I'm pretty sure newer rocker-momentary switch Ultras are this way, as well
>as the 4/5/20 machines with similar switches. Pulling the plug (or
>otherwise removing mains power connection--i.e. turning off an outlet
>strip that the plug is connected to) is the only way to completely remove
>power from these systems.
>
>You may be onto something here. I still wish someone with a bit more clue
>about power supplies would respond to this. It could be a cool use of the
>remaining bits of some systems. I've seen some that from the smoke marks
>are probably not rescuable without a few thousand dollars worth of time
>and equipment, and I don't think anyone on rescue is stupid enough to
>think a random IPX is worth a thousand dollars to "save."
>
>--Rob
>_______________________________________________
>rescue list - http://www.sunhelp.org/mailman/listinfo/rescue


Curtis Wilbar
Hawk Mountain Networks
rescue at hawkmountain.net

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