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Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!tektronix!orca!pogo!jutz
From: jutz@pogo.UUCP (Curt Jutzi)
Newsgroups: net.micro.atari
Subject: Re: Bus contention
Message-ID: <2365@pogo.UUCP>
Date: Thu, 30-Jan-86 11:39:50 EST
Article-I.D.: pogo.2365
Posted: Thu Jan 30 11:39:50 1986
Date-Received: Sat, 1-Feb-86 05:44:29 EST
References: <2048@watdcsu.UUCP>
Reply-To: jutz@pogo.UUCP (Curt Jutzi)
Organization: Tektronix, Beaverton OR
Lines: 13
Summary: 

In article <2048@watdcsu.UUCP> dmcanzi@watdcsu.UUCP (David Canzi) writes:
>To refresh a 640 by 400 bit screen 70 times per second from memory 16
>bits wide requires reading memory 1.12 million times per second.  It
>takes 4 clock cycles (minimum) for the processor to read a word from
>memory.  I would assume the same applies to the screen logic, *plus*
>the time it takes to get control of the bus before reading, and
>relinquish it after reading.  With an 8 megahertz clock, the screen
>must be slowing down the processor by at least a factor of 2.

What's wrong with duel ported memory?

		Curt Jutzi
		tektronix!pogo!jutz