Path: utzoo!attcan!uunet!husc6!bbn!uwmcsd1!ig!agate!ucbvax!ucsfcgl!cca.ucsf.edu!root
From: root@cca.ucsf.edu (Computer Center)
Newsgroups: comp.arch
Subject: Re: Sw vs. Hw BitBlit.
Summary: word blit is not bit blit
Keywords: BitBlit.
Message-ID: <1313@ucsfcca.ucsf.edu>
Date: 28 Jul 88 00:31:28 GMT
References: <399@ma.diab.se>
Organization: Computer Center, UCSF
Lines: 20

It's an old debating trick to try to make points against the opposing
view by mis-characterizing it and then arguing against the distorted
image.

Every one posting on this subject advocating cpu data shuffling for
displays has tried to fake us all out by pretending that this is
done in word sized units all neatly aligned on word boundaries.

Now let's see your software timings for real _bit_blit_ operations
such as moving a block 37 bits wide aligned starting at bit 17 in the
source position and starting at bit 29 in the destination position
on a machine with 32-bit registers and data paths.


Thos Sumner       (thos@cca.ucsf.edu)   BITNET:  thos@ucsfcca
(The I.G.)        (...ucbvax!ucsfcgl!cca.ucsf!thos)

OS|2 -- an Operating System for puppets.

#include <disclaimer.std>