Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!ll-xn!adelie!necntc!husc6!husc4!grunau_b From: grunau_b@husc4.harvard.edu (justin grunau) Newsgroups: comp.sys.atari.st Subject: Re: ST-MS DOS Emulator Message-ID: <867@husc6.UUCP> Date: Thu, 11-Dec-86 17:25:43 EST Article-I.D.: husc6.867 Posted: Thu Dec 11 17:25:43 1986 Date-Received: Mon, 15-Dec-86 20:04:23 EST References: <8612110915.AA24407@ucbvax.Berkeley.EDU> Sender: news@husc6.UUCP Reply-To: grunau_b@husc4.UUCP (justin grunau) Organization: Harvard Science Center Lines: 44 In response to BO628524@CCNYVME.BITNET, I can say a number of things about the paradox software emulator. First of all, I wish to stress that the emulator is BY NO MEANS nor by anybody I am aware of (least of all paradox) claimed to run at anywhere near 100% the speed of an 8088 (whatever that means: an 8088 running at what MHz, for instance?). Basically, it has two modes, one of which is more fully clone- like than the other. The non-fully-clone mode is supposed to run at about 70% the speed of an IBM PC, not even an XT. (so, yes, it would be faster than a PC jr.); the clone mode is supposed to run at more like about 20% to 30%, if I remember properly. I have never been totally sure what the difference was, except I know it involves at least the difference between direct screen writes of characters and direct screen writes of graphics. Apparently, direct screen writes are done by an enourmous amount of MS-DOS software: more than you would imagine. And the graphics are fairly easy to emulate, whereas the character data (this is by word of mouth of the guy who programmed the emulator, who is quite willing to converse at length over long-distance with total strangers) has to be simulated, since of course direct writes of character data involves writing no more than an ascii value to memory, whereas to plot the character we need to write the bitmap to memory. I am not sure why this would involve such a huge drop in speed, when of course the ST OS provides means of writing streams of ASCII bytes that will be turned into bitmaps, so I don't see why it is any slower than the ST writing text; but if the people who market the emulator say that it can run as slowly as only 30% the speed of a PC, I think we have no reason to doubt them, since it is hard to imagine anything running THAT slowly. Lastly, on the price: the emulator is sold at the low price of approx. $69 ONLY if you also buy the 5.25" floppy drive that Paradox sells with it. It goes for the average 200 and some tens. In fact, the author told me they may ONLY offer it with that drive. The system has to be booted off such a drive, though you can store the MS-DOS files on an Atari hard disk partition and run your programs from the hard disk. Oh, and I don't see why Atari would worry about competing with a software emulator. Hardware and software emulation are two different worlds: two different price brackets and two different types of performance; I see no plausible source of competition... JJMG