What does Atari do better than Amiga?

[christos]

There is already an OS running on both systems, it's called EmuTOS.

[Frank B]

They're both distinct and awesome!

[Newsdee]

I've always been an outsider to the Amiga/Atari world, but my experience in Europe was like people trying to bring back Latin but then also trying to charge you for using it. Basically it felt held back by projects trying to make money mostly, and as a result, not very willing to collaborate. It felt fragmented with similar solutions competing with each other. Meanwhile, Windows and Linux were forging ahead with thousands of people working in free and open source projects.

I'm not trying to make an free/OSS vs close source statement here, just saying the realities I've observed. It seems better now thanks to open hardware / FPGA open source projects where collaboration is back thanks to a few brave devs willing to go against the flow and allow others to reuse their work.

[darklight]

Not sure if I understand the purpose of this question.

If you are talking base original machines (ST vs A500), then the ST has a slightly higher (was it 10%?) clock speed than the Amiga, which meant a slight advantage to the ST when doing CPU bound tasks. The only application of the top of my head where this may have had an impact was 3d graphics, including games. I guess when the Amiga had no custom chip to do a task (and it had quite a few), then it has to use the CPU, and having the same CPU as the ST, the ST would be 10% (or so) faster.

I'm not really familiar with the Amiga's disk drive, but I know the ST was mostly compatible with the PCs DOS disk format (not high density - only 720kb).

But then you are talking about FPGA, which means effectively Amigas or STs that are running on the same hardware, so there is no point discussing the above differences. You presumably want to be talking about software differences, but then whats the point unless someone's going to be writing new software for new machines. This seems quite unlikely to me, but I'm happy to be proven wrong.

[tatouine]

I think the answer is

[Cyprian]

[tatouine]

Right of course... Guru mediation

[Frank B]

Got that right! The blitter is absolutely awesome in the ST.
It's faster than the Amigas for window to window translation providing the ratio of fringe to inner area is weighted to the inside.
I raster timed it recently with an 18 word 20 line high single plane copy with fringes. The STE beat the Amiga with all bitplane DMA switched off.
Ie it's faster at this than the Amigas best possible case. It's faster than the 1200! It pulls ahead by a huge margin when bitplane DMA was active,
To do a general purpose copy (where bits are preserved in the dest), the Amiga runs at CPU 8 cycles per word with 1 inactive 2 cycle tick.
This figure drops when bitplane DMA steals cycles from the Amiga blitter.
The ST runs at 8 cycles for the interior and 12 for the fringes. That's with an 8 mhz clock and nothing stealing cycles.

The Amiga is better at masking with complex blits but there's a trick you can do with the end masks which evens the score.
The Amiga blitter can do area fill and line draw. The ST blitter can mirror a bit image in four passes or magnify it via its smudge indirect addressing mode.
The ST blitter has a 24 bit range too. Stick a monster in and you have 12 meg of RAM for blitter sprites

They are both awesome. The ST one is just seriously underrated. Atari did real good work there.

[Frank B]

So now that we are looking at upgrading the old workhorses with FPGA updates. There are a lot of stuff in the Amiga which would be a great upgrade to Atari. So I've been wondering what in the Atari would be good to upgrade the Amiga with.

By the sounds of it Amiga would benefit with Atari blitter upgrade. Could you replace the Amiga blitter with Atari blitter and it would give the same advantages?

Not really. The Amiga API would expect to have 3 sources and one destination. The ST blitter would be useful for font blitting from fast RAM though.
Better to just expand the range of the Amigas.

[Frank B]

That's interesting. What do you mean by expand the range of Amiga's?

The Amiga chipset can only DMA to and from chip ram. That's a 2 meg limit.

[joska]

So I've been wondering what in the Atari would be good to upgrade the Amiga with.

Hardware-wise the Amiga is pretty much superior to the ST. However, there is one really, really annoying thing with the Amiga - the processor status pins are not connected so the Amiga chipset has no way to determine if the CPU is in supervisor mode or not. The result is that all code can access all hardware all the time.

On the ST, user code usually runs in user mode, and the CPU switch to supervisor mode when the OS is called. Access to hardware registers (and low memory where system variables, interrupt vectors etc are located) is restricted to supervisor mode by the chipset, so a software can't mess up hardware settings by accident. If a program in user mode attempt to access e.g. the floppy controller an exception will be raised and the program is killed by TOS. On the Amiga OTOH a simple rogue pointer can write random values to hardware registers and OS variables/code/data and cause everything from vague problems to solid crashes and even corrupt disks.

Changing this now does not make sense though, as even the OS access hardware in usermode. Such a change will cause huge compatibility problems, even with OS support for it.

[ijor]

Hardware-wise the Amiga is pretty much superior to the ST. However, there is one really, really annoying thing with the Amiga - the processor status pins are not connected so the Amiga chipset has no way to determine if the CPU is in supervisor mode or not. The result is that all code can access all hardware all the time.

That's interesting. It also means that the system doesn't really know, at least not with 100% certainty, when the CPU is running an interrupt acknowledge cycle.