Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!zaphod.mps.ohio-state.edu!usc!apple!well!farren
From: farren@well.UUCP (Mike Farren)
Newsgroups: comp.sys.amiga
Subject: Re: A new Amiga...
Message-ID: <15640@well.UUCP>
Date: 23 Jan 90 13:06:44 GMT
References: <4144@wehi.dn.mu.oz> <1051@sdrc.UUCP> <10302@microsoft.UUCP> <15588@well.UUCP> <5415@tekig5.PEN.TEK.COM>
Lines: 55

wayneck@tekig5.PEN.TEK.COM (Wayne C Knapp) writes:

>   a) While drawing both systems are limited by the bus interface to the
>      graphics memory.  This is the real bottle-neck.  

Indeed.  And it's a much more significant bottleneck on the IBM graphics
systems than it is on the Amiga - you do NOT get direct access to the
graphics memory on an IBM system (except CGA, but who cares?).  You have
to go through the hardware on the graphics adapter, which creates its own
benefits and problems.  Benefits: if you are doing single-color fills, etc.,
the hardware handles the bitplane selection for you, and you can do all the
planes with only one write.  Nice.  Drawbacks: if you are doing general
blitting, you must do it one plane at a time, with significant setup 
required between blits (yeah, yeah, BitBlt software, not blits as the Amiga
knows them, but still...)

>   b) While drawing at okay speeds - the Amiga system blitter calls have
>      a huge amount of overhead in them so much that a tiny blit takes 
>      about 3 milli-seconds.  This really hurts the the Amiga since it
>      3 msec. is long time to waste in computer time.

Not germane.  Have you ever used the standard graphics calls available
in the Microsoft C Compiler graphics library?  Slow isn't the word...
For maximal speed, regardless of the system, you don't use the packaged
routines - they are always too general for optimal speed.  The Amiga's
ROM routines are actually about the most efficient I have ever seen, as
far as packaged routines go, and suffice for most purposes just fine.

>   c) Most people talk about blazing blitter speed have never written code
>      that uses that blitter and don't know what they are taking about.

However, I am NOT one of those people.  My blitter routines have been hand-
coded from day one.  I DO know what I'm talking about, thank you.

>Huh?  My 25Mhz 386 with VGA 100Mbyte disk cost $2770?  I does bet my Amiga 1000
>hands down in everything as far as speed goes.  But you mean I can buy a new
>Amiga 500 system with say 20Mbyte hard disk for less than $400? Also PC clone 
>prices have dropped a lot since I last bought.  You need to get up to date. 

The article in question was talking about 16-MHz '386 systems with VGA,
running Flight Simulator.  You don't need a hard drive to run FS.  The lowest
price I've seen for a 16MHz '386 system with VGA and monitor is around
$1700.  There may be lower prices, but I haven't seen 'em.  An Amiga 500
system with monitor can be had for about $750.  "Three times the price"
was exaggerating just a bit  - it's actually only 2.2 times the price, or
so.  And you STILL don't get multitasking :-)

>I think that is one reason why the Amiga is having a hard time in the market,

So you say.  But define "hard time".  Last I heard, Amigas were still selling,
and Commodore was still profitable.  The Amiga will NEVER have the market
share that the PC clones have.  Never.  But so what?

-- 
Mike Farren 				     farren@well.sf.ca.usa