Steve_Godun@rubbs1.UUCP (Steve Godun) (05/19/88)
The chances of an Amiga running ST software is about as remote as seeing a sperm whale climb up Mt Everest and announcing that McDonalds hamburgers are cheap substitutes for floor wax.
Why? First, the programming invloved would be too extensive, taking up at least 400K-500K, which for many Amiga owners would render the "ST Emulator" worthless, since all they have is 512K. Next, the speed of the emulator would be about nil, since an Atari 1040ST running at a full 8Mhz can emulate a wimpy 6502 Atari 8-bit at about .5Mhz. Since the Amiga is almost a full point slower than the ST (8Mhz for the ST compared to 7.16Mhz on the Amiga), the Amiga would process at about .00001Mhz running ST soft
w
are. Third, since most games (since that's what you'd be running, so you say) run in ST low resolution, which is half the resolution of the Amiga screen both vertically and horizontally. Thus, for each refresh cycle of the screen, the Amiga would have to color in FOUR pixels to match ONE ST pixel, slowing down the Amiga even more.
If you think I'm putting down the Amiga, you're basically right. Being an ST owner and avid Atarian since '79, I can give you many reasons why the Amiga can't stand up to the ST, but I don't want to start a war and I'm sure you have the maturity not to start one either.
More vaporware for the Amiga will be announced shortly.
-STeve
PS: Why do you think the ST can emulate a Mac and the Amiga can't?eric@hector.UUCP (Eric Lavitsky) (05/20/88)
In article <48.229281A2@rubbs1.UUCP> Steve_Godun@rubbs1.UUCP (Steve Godun) writes: >The chances of an Amiga running ST software is about as remote as seeing a sperm >whale climb up Mt Everest and announcing that McDonalds hamburgers are cheap >substitutes for floor wax. Thank the lord! >Why? First, the programming invloved would be too extensive, taking up at least >400K-500K, which for many Amiga owners would render the "ST Emulator" worthless, >since all they have is 512K. Next, the speed of the emulator would be about >nil, since an Atari 1040ST running at a full 8Mhz can emulate a wimpy 6502 Atari >8-bit at about .5Mhz. Since the Amiga is almost a full point slower than the ST >(8Mhz for the ST compared to 7.16Mhz on the Amiga), the Amiga would process at >about .00001Mhz running S Well, not exactly. Remember - a good chunk of that 8Mhz on your Atari is usurped for video control and refresh as well as floppy disk I/O - the Amiga has extra support hardware to offload it's 68000 from doing this. >ware. Third, since most games (since that's what you'd be running, so you say) >run in ST low resolution, which is half the resolution of the Amiga screen both >vertically and horizontally. Thus, for each refresh cycle of the screen, the >Amiga would have >to color in FOUR pixels to match ONE ST pixel, slowing down the Amiga even more. Not really guy - the Amiga has a very flexible display architecture, it can even stoop down to the Atari's "low resolution" mode (320x200) - 'cept it can do it in 32 colors at a time and more with some tricks. Even if it were in 640x200 mode, the Amiga would shove display bits around faster than the ST thanks again to it's custom video co-processor. >If you think I'm putting down the Amiga, you're basically right. Being an ST >owner and avid Atarian since '79, I can give you many reasons why the Amiga >can't stand up to the ST, but I don't want to start a war and I'm sure you >have the maturity not to start one either. Wrong - you *do* want to start a war, otherwise you wouldn't have said that you were putting the Amiga down. If the ST is so great, why do you find it necessary to put the Amiga down in public so? I'd really recommend you learn something about the Amiga before continuing any further (hey, like read the manuals - you can find them in any B Daltons). >More vaporware for the Amiga will be announced shortly. > > -STeve Betcha I can name more ST vaporware products than you can name Amiga vaporware products ;-) >PS: Why do you think the ST can emulate a Mac and the Amiga can't? Why don't you read David Small's recent message in Comp.sys.amiga and find out. Oh, you mean you don't already read that group? Sounds like you're not very informed then about what's going on in the Amiga community - I make it a point to read this ST group as well as ST oriented magazines so *I* know what the ST is all about. Hey - since you're on rubbs why don't you stop by the JAUG (Jersey Amiga User's Group) meeting at the Rutgers Physics Auditorium tommorrow evening (Friday, May 20th, 7:30 P.M.) and see some of the neat things an Amiga can do. We're gonna have the Amiga User Group premiere of a fully interactive 3D editing and animation system called Caligari - it may open your eyes a bit. Cheers, Eric ARPA: eric@topaz.rutgers.edu or eric@ulysses.att.com UUCP: {wherever!}ulysses!eric or {wherever!}rutgers!topaz!eric SNAIL: 34 Maplehurst Ln, Piscataway, NJ 08854 "To err is human; To really f*ck up requires the root password."
wayneck@tekig5.TEK.COM (Wayne Knapp) (05/20/88)
In article <48.229281A2@rubbs1.UUCP>, Steve_Godun@rubbs1.UUCP (Steve Godun) writes: > The chances of an Amiga running ST software is about as remote as seeing a sperm whale climb up Mt Everest and announcing that McDonalds hamburgers are cheap substitutes for floor wax. > Get your facts right. 1. The ST and Amiga both have 68000. This is a very different story than a 68000 emulating a 6502. 2. An Amiga can be expanded up to 8 megabytes without too much troble just expensive. 3. The amiga low resolution is 320x200 32 color. I own both machines. I like the ST better, but I see no reason why a 1Meg Amiga couldn't emulate a ST at 1/2 speed. Wayne Knapp
dillon@CORY.BERKELEY.EDU (Matt Dillon) (05/21/88)
>Why? First, the programming invloved would be too extensive, taking up at least 400K-500K, which for many Amiga owners would render the "ST Emulator" worthless, since all they have is 512K. Next, the speed of the emulator would be about nil, since an Atari 1040ST running at a full 8Mhz can emulate a wimpy 6502 Atari 8-bit at about .5Mhz. Since the Amiga is almost a full point slower than the ST (8Mhz for the ST compared to 7.16Mhz on the Amiga), the Amiga would process at about .00001Mhz running S > You obviously have little or no experience writing emulators. The *actual* reason is that there is no reason any Amiga owner would ever want to emulate an Atari. -Matt
NETOPRHM@NCSUVM.BITNET (Hal Meeks) (05/21/88)
Just what I needed -- a good joke to brighten the day. Next thing I hear will be ST owners complaining to Commodore for updates to KS 1.2....... --hal
shaulp@pnet02.cts.com (Shaul Peleg) (05/21/88)
Why don't you READ comp.sys.amiga,then,if you find something wrong with the
Amiga,you can open your trap. Can't you shut up? Why do you want another
computer war?
[The rest was answered by Eric Lavitsky, so I don't have to.]
-Sp Amiga fanatical terrorist organization. AFTO (HAFTO)
UUCP: {ihnp4!scgvaxd!cadovax, <backbone>}!gryphon!pnet02!shaulp
INET: shaulp@pnet02.cts.comeric@hector.UUCP (Eric Lavitsky) (05/22/88)
It has been brought to my attention that a portion of my last posting
was in error. This is correct - I said what I said, not what I meant :-)
What I said was that the ST 68000 is usurped for video refresh - this
is of course incorrect. What I meant to say was that ths ST's 68000
is usurped to move information around on the screen (including any
text). I was aware of this all along, guess I slipped 'cos I was
a little peeved at the tone of the original message - my apologies
to all.
I stand behind the rest of my message. I post this merely as a correction,
now perhaps we can get on to more constructive discussion.
Eric
ARPA: eric@topaz.rutgers.edu or eric@ulysses.att.com
UUCP: {wherever!}ulysses!eric or {wherever!}rutgers!topaz!eric
SNAIL: 34 Maplehurst Ln, Piscataway, NJ 08854
"To err is human; To really f*ck up requires the root password."dillon@CORY.BERKELEY.EDU (Matt Dillon) (05/23/88)
:What I said was that the ST 68000 is usurped for video refresh - this :is of course incorrect. What I meant to say was that ths ST's 68000 :is usurped to move information around on the screen (including any :text). I was aware of this all along, guess I slipped 'cos I was :a little peeved at the tone of the original message - my apologies :to all. Correct me if I'm wrong, but my understanding was that in color mode video refresh does not take cycles from the 68000, but in monochrome mode video refresh DOES. -Matt
wayneck@tekig5.TEK.COM (Wayne Knapp) (05/24/88)
In article <8805222049.AA02208@cory.Berkeley.EDU>, dillon@CORY.BERKELEY.EDU (Matt Dillon) writes: > :What I said was that the ST 68000 is usurped for video refresh - this > :is of course incorrect. What I meant to say was that ths ST's 68000 > :is usurped to move information around on the screen (including any > :text). I was aware of this all along, guess I slipped 'cos I was > :a little peeved at the tone of the original message - my apologies > :to all. > > Correct me if I'm wrong, but my understanding was that in color > mode video refresh does not take cycles from the 68000, but in monochrome > mode video refresh DOES. > > -Matt Yes you are wrong. In fact your postings show you have little idea of how the ST really works, and I'm being to think you don't really understand what happen in the Amiga either. Anyway here is the facts. Unlike the Amiga the ST screen size is always 32k bytes. This of means that as you increase the resolution the bits/per pixcel decrease. Hence while you can normally get only 16 colors in low resolution, there are only 4 colors in medium and the monochrome mode of has the highest resolution. There is no interlacing and no overscan (two things the ST should have, these are outstanding features on the Amiga). Anyway no matter what screen resolution you use the 68000 doesn't see any differences in memory access. Now we come to the part that most Amiga people are really goofed up about. Under normal conditions the 68000 will at most access memory every other cycle. There are a few exceptions, but they don't happen very often. So as it turns out at least half of possible memory cycles are used by the 68000. The Amiga and the ST both have extra hardware to use the memory extra cycles. The Amiga has more hardware doing that, but the ST actually has hardware doing some of the same things that the Amiga does. The Video Shifter in the ST uses the bulk of the excess memory cycles. It simply moves the memory out the display hardware. It doesn't do this during vertial retrace so the are still left over cycles. These get used by the DMA stuff and the DMA can steal cycles from the CPU. Normally only a few cycles can be lost to the 68000 without DMA. That is the few times a the 68000 and the video shifter get out of sync the 68000 has to wait a cycle to get it back in sync so that the Video Shifter and 68000 are using alternate cycles. The Amiga is far more complex. During "normal operation" the Amiga will lose more cycles than the ST and it has to stay in sync with 4 things instead of 2. Still the idea is the same - alternate cycles go to 68000 with the others going to support hardware. The Amiga has more flexibity in graphics modes, but that amount of cycles the 68000 gets varies with the modes you using. The Amiga graphics modes are very flexible from about 320 x 200 1 bit plane to about 704 x 452 4 bit planes interlaced. Or another way to think of it is 8k of memory to around 150k of memory. At some point, I think about about 40k of graphics memory the graphics refresh starts cutting into the 68000 cycles. This is easy to test, but I haven't done it for some time, just write a basic program and time it in the various display modes. Things like blitters and the copper do help out but are not always useful for every program. The copper in my mind is much neater than the blitter and is much more unused than the blitter. Anyway the Amiga pays for it's flexiblity in general speed. Some things that lend then selfs to the extra hardware the Amiga has do fine. (windows are a good example of this) Other things can slow down depending on how much flexiblity of the Amiga is being used. I wish the ST had all the flexiblity of the Amiga. Still there is always a price to pay for flexiblity. In compareable mode the Amiga and ST run neck and neck in speed. (often the ST has a speed advantage) In modes where more graphics specail stuff in being use the basic speed of the Amiga can really slip, but hey at least you can do those modes! If you want something to be proud of, think sound. The basic sound on the Amiga is great - best I've ever seen. And enjoy the flexiblity the machine has. A lot can be done with it. Wayne Knapp
dclemans@mntgfx.mentor.com (Dave Clemans) (05/26/88)
From article <8805222049.AA02208@cory.Berkeley.EDU>, by dillon@CORY.BERKELEY.EDU (Matt Dillon): > > :What I said was that the ST 68000 is usurped for video refresh - this > :is of course incorrect. What I meant to say was that ths ST's 68000 > :is usurped to move information around on the screen (including any > :text). I was aware of this all along, guess I slipped 'cos I was > :a little peeved at the tone of the original message - my apologies > :to all. > > Correct me if I'm wrong, but my understanding was that in color > mode video refresh does not take cycles from the 68000, but in monochrome > mode video refresh DOES. > > -Matt At no time ever does video refresh "directly" take time away from the 68000 on the ST. However because the ST's cpu and the video refresh system run at different clock rates they can get out of sync. This can happen in any mode, and causes an added wait state. This is why when cpu-only speeds of the ST and the Amiga are compared you don't just say that the ST is 8/7.16 (?) percent faster; you have to give a range (say 5-15% or so). Also, monochrome mode on the ST is NOT "directly" slower; the amount of memory that the video shifter has to access in monochrome mode can "normally" be accessed in cycles where the cpu is off the bus, similar to what happens in a color mode. Where you might see a slowdown is: a. depending on the exact program being run, you might see the "out of sync" condition described above in the first paragraph more often. b. normally the ST has a not insignificant amount of code connected to the vertical blanking interrupt (and user programs can enable other video interrupts). This code will get called more often in monochrome mode. dgc