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Path: utzoo!utgpu!water!watnot!watmum!smvorkoetter
From: smvorkoetter@watmum.UUCP
Newsgroups: comp.sys.ibm.pc
Subject: Re: PCJR can it do cga (color graphics)
Message-ID: <853@watmum.UUCP>
Date: Fri, 6-Mar-87 14:28:59 EST
Article-I.D.: watmum.853
Posted: Fri Mar  6 14:28:59 1987
Date-Received: Sun, 8-Mar-87 07:52:50 EST
References: <1530@tekigm2.TEK.COM>
Reply-To: smvorkoetter@watmum.UUCP (Stefan M. Vorkoetter)
Organization: U. of Waterloo, Ontario
Lines: 10


The PCjr has hardware that allows you to write to the screen where it
is found in the PC, at B8000.  This is automatically and transparently
redirected to wherever the video buffer might be (as moved by CONPCJR).
As far as speed is concerned, if you have the Racore expansion, with
384K of 0-wait-state memory, and you fill up your 128K jr base memory
with a RAM disk, a PCjr is actually about 30% FASTER than a PC.  Also,
depsite the lack of DMA, PCjr disk I/O is faster than that of a PC, but
I am puzzled as to why this is so.  Maybe it reads into bigger buffers
to compensate for lack of DMA, and outperforms its cousins doing so.