Message-ID: <171@alberta.UUCP>
Date: Wed, 26-Sep-84 20:54:59 EDT
Article-I.D.: alberta.171
Posted: Wed Sep 26 20:54:59 1984
Date-Received: Fri, 28-Sep-84 04:12:54 EDT
References: <13366@sri-arpa.UUCP> <189@dataio.UUCP> <412@intelca.UUCP>
Organization: his Personal Computer
Lines: 13

I believe (but I'm not sure) that you could rig a normally open pushbutton
between the RESET DRV line and a +5V line on the system bus card adapters.
It would probably need debouncing, though.  I would appreciate it if someone
who knows more about hardware could comment on this, because I am not at
all sure that it would work.  Don't do it on my advice.
-- 
------------------------------------------------------------------------
C. J. Sampson	Snail Canada: #712 11135-83rd ave.	***DISCLAIMER***
ihnp4!alberta!jeff		Edmonton, Alberta	+--------------+
ubc-vision!alberta!jeff		CANADA  T6G 2C8		| These may    |
sask!alberta!jeff					| be opinions. |
		 					+--------------+
"He who spends the storm beneath a tree, takes life with a grain of TNT."

Message-ID: <1500021@iuvax.UUCP>
Date: Thu, 27-Sep-84 15:45:00 EDT
Article-I.D.: iuvax.1500021
Posted: Thu Sep 27 15:45:00 1984
Date-Received: Sat, 29-Sep-84 10:27:24 EDT
References: <171@alberta.UUCP>
Lines: 35
Nf-ID: #R:alberta:-17100:iuvax:1500021:000:1555
Nf-From: iuvax!apratt    Sep 27 14:45:00 1984


I installed a reset switch on a PC just a few days ago...
I determined a couple of ways of doing it, and the one I
chose is probably the worst.

	a) You could rig a button which forces a parity error,
	   and revector NMI to the keyboard-reset routine.
	   I wanted to do this, but couldn't find the place to
	   force the parity error. NMI is active-high, and when
	   the circuitry is holding the line at ground, it's
	   hard to bring it up to +5 to activate it.

	b) You could inform the computer that its power is bad.
	   that's what I did, and it works fine. The result is
	   just like cycling power, except you don't have to turn
	   off the power supply. This is especially good if you
	   have a hard disk and don't want to cycle its power.

There is a pin coming from the power supply which indicates
"power good". If you ground this signal, the entire computer is
placed in a RESET state, and, when this signal goes active again,
a complete power-up restart is executed. The power-good pin is the
one closest to the back of the computer on the motherboard. You can
ground it by connecting it (through a normally-open switch) to the
fifth or sixth pin of the power supply connection (counting from the
back to the front). I'm not exactly sure if this hurts the power
supply -- it could. Also, check those pin numbers -- I may remember
them wrong. But the thing works, and you don't have to cycle power
on the mother board, disk drives, or anything.


----
		"Fritz! They've killed Fritz!"
						-- Allan Pratt
					...ihnp4!inuxc!iuvax!apratt

Message-ID: <424@voder.UUCP>
Date: Mon, 1-Oct-84 20:37:35 EDT
Article-I.D.: voder.424
Posted: Mon Oct  1 20:37:35 1984
Date-Received: Wed, 3-Oct-84 06:46:08 EDT
References: <171@alberta.UUCP> <1500021@iuvax.UUCP>
Organization: National Semiconductor, Santa Clara
Lines: 14

[power down the line-eater]

 >>  There is a pin coming from the power supply which indicates
 >>  "power good". If you ground this signal, the entire computer is
 >>  placed in a RESET state, and, when this signal goes active again,
 >>  a complete power-up restart is executed. The power-good pin is the
I did the same to my Compaq a few weeks ago (using the IBM Tech Ref
Manual as a guide, because Compaq won't supply info to mere users).
Seems to work fine - and is even more necessary on the Compaq, which
requires a minimum of 15 sec after power down before it will LET you
power up again.
Smoke reports follow as necessary.
-- 
Gene E. Bloch (...!nsc!voder!gino)

Message-ID: <440@voder.UUCP>
Date: Fri, 5-Oct-84 20:24:32 EDT
Article-I.D.: voder.440
Posted: Fri Oct  5 20:24:32 1984
Date-Received: Sun, 7-Oct-84 22:01:22 EDT
References: <171@alberta.UUCP> <1500021@iuvax.UUCP>
Organization: National Semiconductor, Santa Clara
Lines: 30

[RESET THAT BUG]

 >  I installed a reset switch on a PC just a few days ago...
...
 >  There is a pin coming from the power supply which indicates
 >  "power good". If you ground this signal, the entire computer is
 >  placed in a RESET state, and, when this signal goes active again,
 >  a complete power-up restart is executed.
 >  -- Allan Pratt
 >  ...ihnp4!inuxc!iuvax!apratt

In addition, if you arrange to store 1234h in location 40:72 before
resetting, the L*O*N*G memory test is bypassed.  I wrote the following
(using debug):
	mov 40,ax ; that's 40 hex, but what does debug know?
	mov es,ax ; set es to paragraph 40
	mov ax,1234 ; yes, that's hex
	es:
	mov 72,ax
	int 20    ; return to DOS
saved it as a com file, and executed it from autoexec.bat.
A freeby: I like a block cursor (or Bloch - see my signature),
so this file includes code to do that as well:
	mov ch,0 ; first row of cursor
	mov cl,d ; last   "  "   "
	mov ah,1 ; set cursor type
	int 10   ; video interrupt
(all hex, natch).
-- 
Gene E. Bloch (...!nsc!voder!gino)

Message-ID: <24700076@uiucdcs.UUCP>
Date: Mon, 8-Oct-84 20:07:00 EDT
Article-I.D.: uiucdcs.24700076
Posted: Mon Oct  8 20:07:00 1984
Date-Received: Wed, 10-Oct-84 04:37:01 EDT
References: <171@alberta.UUCP>
Lines: 4
Nf-ID: #R:alberta:-17100:uiucdcs:24700076:000:82
Nf-From: uiucdcs!seaburg    Oct  8 19:07:00 1984

{}
What does the change you mentioned actually do?  Change some JMP
instruction?