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From: edm@hpfcmdd.hp.com (Ed Moore)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: HELP!!!! How fast will an ATI VGAWONDER work?
Message-ID: <84050009@hpfcmdd.hp.com>
Date: 28 Mar 91 16:35:58 GMT
References: <91078.231000IO91472@MAINE.BITNET>
Organization: HP Mechanical Design Division
Lines: 17

>	What are the standard bus speeds? 
>
>	What determines which bus speed is used?
>
>	How does one change the bus speed (the posting implies one
>can select it -- at least on his Micronics motherboard)?

The most standard bus speed for an AT-bus machine seems to be 8 MHz, just
like IBM defined it with the 8 MHz AT.  I work primarily with HP Vectra 386
systems with 16 MHz, 20 MHz and 25 MHz clock speeds.  Each of these machines
has two bus speeds.  The choice is made with a DIP switch on the processor
board.  This is clearly documented in the hardware manual "Setting Up Vectra
RS".  The factory default bus speed is 8 MHz Async.  The optional choice is
half the clock speed, synchronous.  For example, a 25 MHz system's optional
bus speed is 12.5 MHz.

This is one of those times when you need a good hardware manual.