Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/17/84; site cwruecmp.UUCP Path: utzoo!linus!decvax!cwruecmp!bammi From: bammi@cwruecmp.UUCP (Jwahar R. Bammi) Newsgroups: net.micro.amiga Subject: Re: Amiga vs ST - the debate continues Message-ID: <1365@cwruecmp.UUCP> Date: Thu, 2-Jan-86 21:05:18 EST Article-I.D.: cwruecmp.1365 Posted: Thu Jan 2 21:05:18 1986 Date-Received: Fri, 3-Jan-86 05:32:03 EST References: <872@caip.RUTGERS.EDU> Organization: CWRU Dept. Computer Eng., Cleveland, OH Lines: 116 > From: "ROBERTS, JOHN" > I assume you mean that Atari/authorized dealers have decided to sell the > color monitor as a separate item. If this is correct, I am glad that > Atari has decided to be sensible about the matter. I had read in several > publications that it was not possible to purchase a monitor as a > separate item, and that was one of my main complaints about the > marketing of the ST. I understand that normal NTSC-compatible RGB > monitors cannot be used with the ST. Please correct me if I'm wrong. Yes the color monitor is being sold separately (and has been for the at least the last three months). The ST can be hooked to an analog RGB monitor, but not to a RGBI (ibm PC flavour montitors), quite easily (cables and 3 resistors). > > >> 4) Commodore/Amiga has been fairly open and honest about the internal > >> structure and functioning of their machine, while by comparison > >> Atari has been relatively secretive (specific examples furnished upon > > > Uh, I have the schematics at home, they came with the developers kit, > > availabler to the general public for $300. > > Could you please post a name and address by which such information might > be purchased? (Admittedly shaky justification for posting to an Amiga > mailing list, but since a number of Amiga users are also interested > in the ST, I think it might be forgiven just this once.) In a product > survey conducted by reading every Atari-oriented, Commodore-oriented, > and general interest computer magazine I could find, I was able to > find out a lot more about the internal structure and functioning of > the Amiga than of the ST. Maybe the degree of willingness to communicate > with publishers/reporters has been the main reason for the difference > in coverage, rather than desire for secrecy. The $300 dev. system can be ordered from Richard Frick, Atari Corp,1196 Borregas Ave , Sunnyvale CA 94086. Included in the package is the C compiler, linker, assembler, Uemacs, Libraries, a bunch of utilities, command line processor, schematics, data sheets for some of the commercial chips, icon and shape editor, resource construction set and 2800 pages of docs. So, as you can see the price is in line with the price of the machine. There is also a book due out soon about the internals if you don't want the whole dev. system. (Don't ask me when exactly). > > > >> 6) Most of the Dhrystone benchmarks run on the Amiga (showing slightly > >> slower execution than the ST) have been run with the processor using > >> the same memory as the specialized chips. With an expanded memory > >> space (which could be desired for its own sake) performance should be > >> enhanced, especially for graphics-intensive applications. A faster > >> processor (the 68020) should give a greater increase in performance. > >> What should really give floating point performance a boost is the > >> addition of a good floating point processor chip (of which the 68881 > >> is a logical choice for the 68000 family). I expect a 68881 to be > >> available for the Amiga long before the ST gets one (if ever). > > > > Wait, hold on here. Memory outside of the lower 256K on the Amiga is > > slower, not faster. The Dhrystone benchmarks are CPU only, not > > graphics intensive. > > > Hell, if we redesign the ST it will be better also. > > Incorrect. The basic machine comes with 256K RAM, and another 256K > can be added for about $200. (There is a separate non-user-accessible > RAM to hold the operating system in current machines, unlike the > ST, which eats up a big chunk of user RAM to hold the OS in current > machines.) The Amiga treats the "internal" 512K user address space > as a contiguous and uniform chunk of memory which is shared by the > processor and the special-purpose graphics, sound, and I/O chips. > This memory is designed to be faster than needed for any particular > device in order to minimize contention (it is effectively a > time-slice multiport memory), but for some applications there will > still be a certain amount of contention, thus slowing down the > processor. The Amiga is designed to make it easy to add external > memory, which is accessed only by the processor. Processes running > in external memory (still in the same linear address space, of > course) are not subject to slowdown from memory contention, and > will therefore be as fast, or sometimes significantly faster than > processes in the "chip memory". > In my opinion, allowing the graphics processor to only access the 'internal' memory is rather limiting tradeoff, if, for instance you are writing applications that want to define frames in the process address space and want to change the screen base pointer to the frame (a popular 'trick' ), and so on. $200 sounds a little steep for 256K of memory, considering that 2Meg addon cards are going for ~$350 for the ST. But i guess the pricing for peripherals and software for the Amiga should be expected to be propotionally higher. BTW the OS in Eprom (this month in rom) is out for the Atari, so now you have lots of memory. > I mentioned graphics in reference to Dhrystones because there are > certain applications that are both computation- and graphics- > intensive, and because the computational performance of the Amiga > (and, I suspect, the ST) can be affected by what is being displayed. > > I am thinking of the 68881 not as a redesign, but as an add-on > component. The 68881 is a very expensive ($240 - EDN 11/28/85) > and, until very recently, nonexistent chip, but its eventual release > was announced quite a while back. While it would not have been > logical to design either the Amiga or the ST with a 68881, it would > have been sensible to design the machines so one could be added later. > With its comprehensive external port, I think Amiga has done this. > > I assume that both companies are thinking of eventually making improved > versions of their machines, with faster processors, etc. The > piggyback board with 68020 and 68881 is an unexpectedly early upgrade. > The current hot rumor is that Atari will be showing its 32 bit processor based add on box, nickednamed 'TT', at CES. The ST will supposedly be a front end for this cruncher. I hope they use 68020 and not a 320XX. -- Jwahar R. Bammi Usenet: .....!decvax!cwruecmp!bammi CSnet: bammi@case Arpa: bammi%case@csnet-relay CompuServe: 71515,155