henry@utzoo.UUCP (Henry Spencer) (06/19/85)
***FLAME WARNING*** Those who are easily singed should read no further. > ... It will also come with > one built-in 3 1/2" disk drive, with > an approximate capacity of 800K. > ... > There is no > hard disk as of yet, but third parties > will no doubt jump in... I've thought for some time that the first outfit with a Mac-ish product that includes a *hard disk* in the standard configuration is going to clean up. Evidently the Amiga won't be it, since hard disks aren't considered important enough to even be available! Some of us have known for a decade that storing your data on floppies is like running with one foot in a bucket. Having a hard disk always there would do wonders in eliminating some of the sludge found in micro "operating systems". > ... Those of you who are > starting to foam at the mouth about > the mouse should stop it right now > (you look silly). YOU DON'T? > HAVE TO USE THE MOUSE. The cursor > control keys will move the mouse > pointer, and all mouse functions can > be accomplished from the KEYBOARD > (which also has ten function keys). What would make me foam at the mouth is the prospect of using a system whose mouse has been crippled by the requirement of making it backward compatible with a keyboard. Has it escaped these people's attention that using cursor keys *also* requires moving one hand away from the home position? > But who needs sprites My sentiments exactly. They're a vestige of the computer game market; the silicon/board real estate spent on them is wasted. > Since a lot of the graphics is done > using dedicated hardware, its FAST. > There are features like hardware line > drawing and filling (you just tell it > where to draw the line, with no > tiresome calcuations of each point on > the line). Just as important as it being fast is getting it RIGHT. I wonder if it handles all the troublesome cases correctly? I also wonder just how flexible this hardware is. Not that it's impossible to do it right, just non-trivial. > One of the nicest features of the > graphics hardware is that it uses the > "off-phase" periods of the system > clock, when the processor is not using > the bus. This is really interesting, since the 68000 *has* no "off phase", unlike the Motorola 8-bit chips. In fact, the 68000 is pretty much bus-bound, and there isn't a lot of spare bandwidth to go around. There is a smell of snake oil in the air... > sound and i/o for the most part run > in the background, without taking up > any processor time at all. When the > processor tells the graphics chip to > draw a line or fill a shape, it > doesn't have to hang around and wait > for it to get done... > Likewise, when the processor request > disk access, the DMA controller takes > over... On a machine as bus-intensive as the 68000, hardware that also wants the bus is definitely going to slow the cpu down substantially. Maybe not as much as if the cpu were doing the work, but it won't be trivial. > (the DMA > controller also make for FAST, FAST, > FAST disk access). Haven't these people ever heard of seek times and rotational latencies? DMA is not going to do a damn thing about them, and they're the dominant factor in disk slowness. > I was told that > with medium-heavy animation going on, > the 68000 would only lose about 5% of > its throughput speed. I have this bridge to sell you... > ... On the Amiga, > practically every graphics feature > that you can think of is part of the > Operating System, so that the commands > can be called by any program... <enter heavy sarcasm mode> Amazing. The microcomputer world has discovered the subroutine library, even if they do insist on calling it "part of the operating system", which it probably isn't in any strict sense of the term. If they keep at it, maybe they'll discover some of the other things the rest of us knew about fifteen years ago. <end h.s. mode> > ... The system has printer > drivers for graphics dumps to 6 > different printers (including Epsons, > ink jets, and color printers) BUILT > INTO (!!!) the OS! What if my printer isn't one of those six? Building such things into the operating system is a *rotten* idea unless there is a way to bypass it when things change. > ... With the power > of the graphics processor, virtually > any kind of complicated graphics and > animation can be accomplished from > high level languages like C (and > probably BASIC) WITHOUT MACHINE > LANGUAGE programming. ... Yawn. What else is new? Complex graphics and animation are very seldom written in machine language these days, except in backward parts of the world (like the microcomputer community). > The DOS is not like any other, > but is said to have "every conceivable > feature that you could ever think of, > and then some". Would it be too much to ask for a simple, small, clean, consistent set of well-chosen features instead? > It supports > heirarchical directories... > The most amazing feature of Intuition > is that it is a full MULTI-TASKING > OS!!! You can have as many > applications as memory will permit > RUNNING AT THE SAME TIME... Those who will not learn from Unix are condemned to re-invent it. Badly. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
skinner@saber.UUCP (Robert Skinner) (06/20/85)
> ***FLAME WARNING*** Those who are easily singed should read no further. > > > One of the nicest features of the > > graphics hardware is that it uses the > > "off-phase" periods of the system > > clock, when the processor is not using > > the bus. > > This is really interesting, since the 68000 *has* no "off phase", unlike > the Motorola 8-bit chips. In fact, the 68000 is pretty much bus-bound, > and there isn't a lot of spare bandwidth to go around. There is a smell > of snake oil in the air... > You are right that the 68000 has no explicit "off phase", but I wouldn't call it bus-bound either. Just because the address lines are active, the processor doesn't have to hog memory. As an example, a couple of companies ago I helped build a graphics terminal with the 68000 and 640x480 resolution. 60Hz refresh required a pixel rate of about 28MHz, which implied that we did a 16-bit video read every 570ns. Now, 570ns is a long time for DRAMS, so we double-buffered the memory, with 280ns (3.5MHz) access cycles and let the video access memory at regular intervals with priority. We put the 68000 clock at 7MHz and it syncs up to the memory access slot allotted for it. It's true that the 68000 asserted it's memory lines about half way through the video memory cycle, but the arbitration logic didn't switch them in until the appropriate time. So, the two systems co-existed and the 68000 was forced to wait only about %5 of the time, because very few instructions take a non-multiple of 4 cycles. I know that 7MHz is not blazing for a vanilla 68K, but 640x480 resolution is good for a pc. Of course there are trade offs that can be made: the clock speed could be set at 14MHz and video could fetch 32-bit words. The point is that 68K systems work with double-buffered memory without *terrible* penalties, and no snake oil either. ----------------------------------------------------------------------------- Name: Robert Skinner Mail: Saber Technology, 2381 Bering Drive, San Jose, California 95131 AT&T: (408) 945-0518, or 945-9600 (mesg. only) UUCP: ...{decvax,ucbvax}!decwrl!saber!skinner ...{amd,ihnp4,ittvax}!saber!skinner
matt@ethz.UUCP (Martin Matt) (06/25/85)
> >> ... Those of you who are >> starting to foam at the mouth about >> the mouse should stop it right now >> (you look silly). YOU DON'T? >> HAVE TO USE THE MOUSE. The cursor >> control keys will move the mouse >> pointer, and all mouse functions can >> be accomplished from the KEYBOARD >> (which also has ten function keys). > >What would make me foam at the mouth is the prospect of using a system >whose mouse has been crippled by the requirement of making it backward >compatible with a keyboard. Has it escaped these people's attention >that using cursor keys *also* requires moving one hand away from the >home position? It probably has not escaped those people, but giving the user the choice of using keyboard or mouse is definitely a good idea. I worked on a Lilith workstation here at ETHZ and I was often angry about having to use the mouse to move the cursor up one line. Martin Matt ( !cernvax!unizh!vlsivax )
dimitrov@csd2.UUCP (Isaac Dimitrovsky) (06/27/85)
[] >> The DOS is not like any other, but is said to have "every conceivable >> feature that you could ever think of, and then some". > > Would it be too much to ask for a simple, small, clean, consistent set of > well-chosen features instead? Bravo!!! And ditto for programming languages, having just experienced the Common Lisp manual. Isaac Dimitrovsky allegra!cmcl2!csd2!dimitrov (l in cmcl2 is letter l not number 1) 251 Mercer Street, New York NY 10012 Just because it's a preconceived notion doesn't mean it's wrong!