Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!ima!mirror!xanth!kent From: kent@xanth.UUCP Newsgroups: comp.graphics Subject: Re: Amiga World Ray-tracing article... Message-ID: <854@xanth.UUCP> Date: Mon, 20-Apr-87 04:54:06 EST Article-I.D.: xanth.854 Posted: Mon Apr 20 04:54:06 1987 Date-Received: Tue, 21-Apr-87 00:13:18 EST References: <629@puff.WISC.EDU> <2985@sdcsvax.UCSD.EDU> <647@puff.WISC.EDU> <239@rocky.STANFORD.EDU> <4612@utcsri.UUCP> Reply-To: kent@xanth.UUCP (Kent Paul Dolan) Distribution: comp Organization: Old Dominion University, Norfolk Va. Lines: 83 Keywords: cost Summary: Amiga max memory is 9.5 meg, not 0.5 meg! In article <4612@utcsri.UUCP> buchanan@utcsri.UUCP (John Buchanan) writes: >In article <239@rocky.STANFORD.EDU> ali@rocky.UUCP (Ali Ozer) writes: >>still use my Amiga. And thanks to multitasking you do not need to sit and >>watch your Amiga grind away on ray-traced images. Besides, the > >Hmmm Last starfighter ship = 250000 polygons. > Amiga memory = 512000 bytes > 2 bytes per polygon = 500000 bytes. ( it seems that under estimating > is the name of the game.) > =============== > Memory available for > raytracer. = 12000 bytes. > > > I fail to see where the multitasking system will reside. I'd also > like to see at least 24 bits per pixel. Whoa! The original Amiga 1000 came with 256K bytes of memory, and there was an easy add on for another 256K bytes. (There was also always a "hidden" 256K bytes where the operating system ("Kickstart") was loaded.) However, the available users memory address space included another 8M bytes of memory, making the original machine an 8.5M byte machine, not a 0.5M byte machine. Since then, Commodore has relinquished claim to another megabyte of memory (of the total 16M bytes provided by 24 bit addressing), permitting it also to be used for user expansion memory. This makes the Amiga a 9.5M byte machine from the user's point of view, today. This is a linear address space, a big improvement over the Baby Blue clones' segmented memory. There are lots of third party vendors providing add on memory units from 0.5 to 8.0 meg for the Amiga. I run a 2.5M byte system at home, and I have yet to run out of memory, even after copying a couple of the 880Kbyte floppies into ram disk to save disk access time. As to the 24 bit frame buffer, I'd like one too, and someday I expect to add one as a peripheral. There is no way I want to pay for a home computer with the memory bandwidth to support that from memory to video display, though, at the price of today's fast memory. The Amiga in HAM mode (see other articles) can display pictures with near photographic realism. More would be nice, but more would always be nice; it just takes paying for. On multitasking: this evening, for a lark, I put up 39 demos with graphics output, all on the screen, all running at once, and all obviously doing something. The windows in which they ran were overlapped, nested, a real mess, and yet the Amiga kept up. With this much junk around, moving a window was worth a 20 second pause, but this isn't a realistic way to use the machine. Practically, like the previous author, I have found myself printing one file, downloading another with kermit, unpacking a third with arc, and editing a fourth with micro-emacs, all at once. This is useful, and it does work. Since all but the arc process (which I usually run memory to memory) are I/O limited, the editing procedes at a comfortable pace, even with everything else going on. It isn't a Cray X/MP, and there is an occassional pause, but that is a small price to pay to get away from serial processing. I'm hardly disinterested; I liked the computer so much I went back and bought some of the stock. However, lack of care by publishers of Amiga reviews leave the Amiga with the reputation of being a slow, half megabyte machine. The floppy disk access is slow, but multi-megabyte memory is possible, and, with add on enough memory to dump the contents of a floppy into ram disk (a ram disk driver is standard as part of AmigaDOS), the machine is screamingly swift. For a graphics type like myself, with it's special purpose graphics coprocesser chips, the Amiga is unexcelled anywhere near it's price, and, except for the resolution/pixel depth limitations of slower memory, exceeds the performance of machines for which I paid $50,000 a decade ago. Kent. -- The Contradictor Member HUP (Happily Unemployed Programmers) // Yet // Another Back at ODU to learn how to program better (after 25 years!) \\ // Happy \// Amigan! UUCP : kent@xanth.UUCP or ...{sun,cbosgd,harvard}!xanth!kent CSNET : kent@odu.csnet ARPA : kent@xanth.cs.odu.edu Voice : (804) 587-7760 USnail: P.O. Box 1559, Norfolk, Va 23501-1559 Copyright 1987 Kent Paul Dolan. How about if we keep the human All Rights Reserved. Author grants free race around long enough to see retransmission rights, recursively only. a bit more of the universe?