[comp.sys.amiga] Mac ][ bashing / blitters are not everything

gnu@hoptoad.uucp (John Gilmore) (08/07/88)

> >>> The Mac ][ still can't animate worth a pint of sour owl shit.
> >No blitter.

My Sun-3/160-C (1152x900x8 color) has no blitter and it is plenty fast.
It *does* have hardware that can merge the data that the CPU writes to the
color card, in with the existing data.  (In fact, it has 8 "rasterop chips",
one per plane, which can all work in parallel.)  But it doesn't do any DMA.
A 68020 makes a GREAT DMA controller, highly programmable and fast.  Most Sun
CPUs already run their memory flat-out at top speed, so any time a DMA
device is touching memory, the CPU is likely to be hung anyway.  The last
Amiga hardware design I looked at ran the CPU at like half the speed of RAM,
so they could use slow, cheap CPU chips.

> 	-It doesn't multitask worth a pint of sour owl shit either, though it
> 	 seems to be acceptable to the Mac users (better than what they had
> 	 before anyway).

Funny, we run A/UX (Almost Unix) on our Mac-II and it multitasks just
fine.  Even though A/UX shipped a year or 18 months late, it is finally
here.  Where is Amiga's Unix, so Amiga users can stop reinventing 10
and 20 and 30 year old software and start moving forward?
-- 
John Gilmore    {sun,pacbell,uunet,pyramid,amdahl}!hoptoad!gnu    gnu@toad.com
      "And if there's danger don't you try to overlook it,
       Because you knew the job was dangerous when you took it"

peter@sugar.uu.net (Peter da Silva) (08/08/88)

The rest of your article is right on... the blitter isn't the problem
with the Mac II. The problem is purely software. *Apple's* software. A/UX
doesn't count... a Mac-II running AUX is just another workstation (JAW-II).

In article <5053@hoptoad.uucp>, gnu@hoptoad.uucp (John Gilmore) writes:
> Funny, we run A/UX (Almost Unix) on our Mac-II and it multitasks just
> fine.  Even though A/UX shipped a year or 18 months late, it is finally
> here.  Where is Amiga's Unix, so Amiga users can stop reinventing 10
> and 20 and 30 year old software and start moving forward?

Where's realtime performance from UNIX? I'll give up my superfast context
switches when they pry my cold, dead, fingers off the keyboard. UNIX on
the Amiga is harder than on the Mac, since to keep all the nice features
of AmigaDOS it will have to run on top of it... whereas the Mac was still
waiting for an O/S when A/UX came along.

One point to note, about the blitter... since the Amiga's memory is split
into two busses, you can run code out of FAST memory while the blitter is
banging away at CHIP memory.
-- 
		Peter da Silva  `-_-'  peter@sugar.uu.net
		 Have you hugged  U  your wolf today?

iphwk%MTSUNIX1.BITNET@cunyvm.cuny.edu (Bill Kinnersley) (08/08/88)

[In "Re: Mac ][ bashing / blitters are not everything", John Gilmore said:]
>
> Amiga hardware design I looked at ran the CPU at like half the speed of RAM,
> so they could use slow, cheap CPU chips.
>
No no, John, you've got it backwards.. The *RAM* runs at *twice* the speed
of the *CPU*. :-)

rminnich@super.ORG (Ronald G Minnich) (08/08/88)

In article <5053@hoptoad.uucp> gnu@hoptoad.uucp (John Gilmore) writes:
>Funny, we run A/UX (Almost Unix) on our Mac-II and it multitasks just
>fine.  Even though A/UX shipped a year or 18 months late, it is finally
>here.  Where is Amiga's Unix, so Amiga users can stop reinventing 10
>and 20 and 30 year old software and start moving forward?
ah, i see, you have multitasking under A/UX. And you run, what,
microsoft word and hypercard and and macpaint and macdraw on this
machine as you are running A/UX?
  And you can run queries on hypercard data bases from A/UX applications?
Be nice to maintain /etc/passwd in a hypercard database, with pictures
and all.
   And you can import MacDraw pictures into the TeX documents under A/UX?
And you can, ..., well you get my drift. Can you, or can't you.
If you can, you have a heck of a nice system there. I might even
buy one. 
   And if you can't, what's the point? That you can build an 
over-priced unix box out of the MAC ][? A box that is about as 
compatible with the Mac OS as an amiga is?
ron
P.S. Damn shame about hypercard. Apple could define the standard
hypertext environment with this product if they would only be as 
open about it as sun is about NeWS. Instead they are using it to 
sell one hardware platform that will only ever be a niche machine.
Thing is, if they opened it up it would probably sell MORE mac ]['s...

dillon@CORY.BERKELEY.EDU (Matt Dillon) (08/10/88)

>> 	-It doesn't multitask worth a pint of sour owl shit either, though it
>> 	 seems to be acceptable to the Mac users (better than what they had
>> 	 before anyway).
>
>Funny, we run A/UX (Almost Unix) on our Mac-II and it multitasks just
>fine.  Even though A/UX shipped a year or 18 months late, it is finally
>here.  Where is Amiga's Unix, so Amiga users can stop reinventing 10
>and 20 and 30 year old software and start moving forward?
>-- 
>John Gilmore    {sun,pacbell,uunet,pyramid,amdahl}!hoptoad!gnu    gnu@toad.com
>      "And if there's danger don't you try to overlook it,
>       Because you knew the job was dangerous when you took it"
>

	John, surely you have been following the various arguments on *THAT*
issue.  The jist is essentially: You might be able to run an operating system
on some machine and get multitasking, for instance OS 9 on an Atari, but that
doesn't let you run all the old software under multitasking, does it.  I.E.
the software under to original/standard OS.

	After all, one can run UNIX on just about anything these days.  If you
have a need to run UNIX (and there are many good reasons to do so), then 
everything is just dandy for you, but if 99% of the users of the machine and
99% of the software for the machine is using the MAC-OS, you cannot truely
say that the multitasking UNIX provides solves the problem in general.

	So in your specific case:  good, fine, great, solved.  But everybody
else still has their book open to the same problem.

					-Matt

daveh@cbmvax.UUCP (Dave Haynie) (08/19/88)

in article <8808100909.AA00265@cory.Berkeley.EDU>, dillon@CORY.BERKELEY.EDU (Matt Dillon) says:
> 
>>> 	-It doesn't multitask ...

>>Funny, we run A/UX (Almost Unix) on our Mac-II and it multitasks ...

> 	John, surely you have been following the various arguments on *THAT*
> issue.  The jist is essentially: You might be able to run an operating system
> on some machine and get multitasking, for instance OS 9 on an Atari, but that
> doesn't let you run all the old software under multitasking, does it.  I.E.
> the software under to original/standard OS.

> 					-Matt

And that's only part of it.  If most users are single-tasking on a machine,
there's a really good chance that not many hardware vendors are considering
the hardware ramifications of multi-tasking.  Which may mean that when you do
start multitasking on such a machine, you may hit hard performance walls that
never surface when you're single tasking.

For example, consider hard disks.  At least on some Macs (don't personally know
about the Mac II), they handle disk I/O using a clever little hack that
basically turns your data ready signal from the hard disk control chip into
DTACK* for the CPU, so you read a full block just about as fast as possible
with the CPU.  Not all that bad for a single-tasking setup, as the program is
sleeping during this transfer anyway.  But come a multitasking OS, and all
of a sudden this becomes a long atomic operation that takes a bite out of 
your performance.  The standard Amiga hard drive controller is a DMA/FIFO
combo that works better than interrupt or Mac-style I/O when you have the
CPU sliced up amoung a number of tasks.


-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {ihnp4|uunet|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
		"I can't relax, 'cause I'm a Boinger!"