Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!saxony!dgil
From: dgil@pa.reuter.COM (Dave Gillett)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: How to hook up turbo switch?
Keywords: turbo 386 clone ami c&t
Message-ID: <318@saxony.pa.reuter.COM>
Date: 14 Aug 90 07:34:03 GMT
References: <2050@sud509.ed.ray.com>
Organization: Reuter:file Inc  (A Reuter Company) Palo Alto, CA
Lines: 20

In <2050@sud509.ed.ray.com> heiser@tdw201.ed.ray.com writes:
>On the case I got, there is a "turbo" button with a two-wire cable
>attahced, with a jumper on the end (with two holes).
>On my motherboard, the "turbo" speed selection is made by setting a
>jumper on a 3-pin jumper.  The instructions say that for low speed,
>jumper pins 1/2, for high-speed, jumper pins 2/3.  

The switch mounted in the case is a SPST (single-pole, single-throw), but
the motherboard wants an SPDT (single-pole, double-throw) switch.  You could
kludge something together with a relay to achieve the necessary effect, but
the best bet is to check local electronic supply places (Radio Shaft, if nothing
else is available) for a replacement switch that fits your case.

Briefly:  The case is designed for motherboards where two pins are jumpered
together for one speed, and not for the other, and the switch goes across the
pins.  You want a switch that connects pin 2 to pin 1 in one position, and to 
pin 3 in the other; it will have three terminals/leads which connect to the
three pins.  (BTW, you're also going to want a connector that slides on over
the pins of the motherboard; try the same shoppe.)
                                            Dave