Path: utzoo!censor!geac!torsqnt!lethe!yunexus!ists!helios.physics.utoronto.ca!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!edcastle!ecwu61
From: ecwu61@castle.ed.ac.uk (R Renwick)
Newsgroups: comp.sys.acorn
Subject: Re: ScreenSize Limit
Message-ID: <7702@castle.ed.ac.uk>
Date: 8 Jan 91 12:55:17 GMT
References: <1991Jan6.150113.15268@alzabo.uucp>
Organization: Edinburgh University Computing Service
Lines: 16

In article <1991Jan6.150113.15268@alzabo.uucp> andras@alzabo.UUCP (Andras Kovacs) writes:
>
>    Does someone know why the maximum ScreenSize is limited to 480K? It means
>that one cannot double-buffer bigger than 240K screens (mode 21/24/28).
>Please reply by E-mail if you feel that the problem is a silly one...
>    Thanks!
>-- 
	There has been a discussion about this before on the net
regarding screen banking.  You probably just missed that one.
	The VIDC chip itself has to be able to access the screen memory
as this is obviusly part of it's job.  There has to be a limit on the
amount of memory it can access just as there is a limit for any machine
architecture, the limit for the VIDC happens to be 480k which means that
there is no way the current VIDC chip can access more this.

Rik