*BSD News Article 11301


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	id AA1535 ; Tue, 23 Feb 93 14:47:29 EST
Newsgroups: comp.unix.bsd
Path: sserve!manuel.anu.edu.au!munnari.oz.au!sgiblab!swrinde!gatech!destroyer!fmsrl7!lynx.unm.edu!umn.edu!csus.edu!netcom.com!hasty
From: hasty@netcom.com (Amancio Hasty Jr)
Subject: Re: Will 386bsd run for Pentium machine without pain?
Message-ID: <1993Feb16.014639.21018@netcom.com>
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
References: <1993Feb12.042349.18579@netcom.com> <78672@apple.apple.COM> <1993Feb15.234758.23855@sco.com>
Date: Tue, 16 Feb 1993 01:46:39 GMT
Lines: 33

In article <1993Feb15.234758.23855@sco.com> md@sco.COM (Michael Davidson) writes:
>
>mg@Apple.COM (Mark Gorlinsky) writes:
>
>>In article <1993Feb12.042349.18579@netcom.com> hasty@netcom.com (Amancio Hasty Jr) writes:
>>>Question: does the pentium have memory block move instruction?
>>>This could be useful for doing bitmap block transfers to
>>>a vga card...
>
>>All of the iX86 cpus have memory block move instructions. The pentium is
>>part of this family and therefore has them too.
>
>However, even on a 486 it is theoretically faster to do a series
>of register loads and stores in an unrolled loop that moves, say,
>16 or 32 bytes per iteration than it is to use the string move instruction
>with a repeat prefix. (I say "theoretically" because unless you are
>getting cache hits on everything there turns out to be little
>measureable difference in practice - certainly if you are really
>writing to a VGA card with an ISA bus interface the limiting factor
>is the speed of the card which is so *slow* that it hardly matters
>what kind of code you use to access it ...)

Tnks we will give it a try and we have VESA local bus and
vesa local bus cards :-)

Amancio


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Amancio Hasty           |  
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