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Playing Atari ST Music on the Amiga with Zero CPU

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Re: Playing Atari ST Music on the Amiga with Zero CPU

#41

Post by rbanffy »

abanana wrote: post #35
rbanffy wrote: post #33

Earlier quoted context omitted.

The Amiga’s heavy focus on TV-friendly timings went deep into the specialised chips to a point it was difficult to upgrade without losing compatibility. Because of that lack of modularity Commodore had to spend more resources to develop improved machines than its competitors. It was not an obvious mistake then, and it’s not clear now what they could have done to better compete with PCs and Macs. They could have made…

True, but "Amiga made lots of assumptions about the use that ended up..." seemed an odd way to phrase it, given that it was originally designed as a games machine, although the plans were expanded later in development. As I understand it, its custom chips were a brilliantly clever solution to a problem that existed at the time . It couldn't be called a mistake, because they couldn't see into the future. As a games ma…

> That made no difference to its productivity software though, did it?

If you build productivity software you’ll prioritise platforms sold for businesses. If most of the units are sold to be used mostly for gaming, your target market gets very small.

Re: Playing Atari ST Music on the Amiga with Zero CPU

#42

Post by rbanffy »

rigonkulous wrote: post #36
rbanffy wrote: post #21

Earlier quoted context omitted.

It’s not really an 8-bit computer, stuck in a weird place between the //e and the Macs. It kind of is a II, but only in a half hearted way, kind of a new Apple ///, but designed for graphics and sound, and nicer at pretending to be a //e. It’s not even the fastest II - that would be the //c+ - nor the last to be discontinued, which was the Platinum//e. It’s a nice machine, but I find it uninspired, a bit like the C12…

Oh darn, actually, I mixed up the IIgs with the //c+, which is the one I really want .. ;)

Same here. Neat, small, and ludicrously fast for an Apple II.

Re: Playing Atari ST Music on the Amiga with Zero CPU

#43

Post by bhaak »

makapuf wrote: post #37
bhaak wrote: post #26

Earlier quoted context omitted.

>> AmigaOS was a pre-emptive multitasking OS > Yes, but without memory protection. That’s why it was so fast. :) Also surprisingly stable all things considered.

I havent seen many desktop like workflows on it with several "big" apps open (and running cpu) at the same time, most ive seen was one software at a time or games. Cooperating with yourself is relatively easier, no ?

Remember that without memory protection everybody shares the same memory and everything is visible to every process. If a process doesn't release all their memory that memory leak will stay even if the process ended.

Shared libraries were typically loaded only once into the system's single shared address space. Any process could potentially overwrite another task's memory or shared library state.

I don't have my old setup ready but if I boot into Pimiga, I get about 60 task and processes running.

If you literally mean "seeing" workflows, because of the small monitors back then, you usually didn't have open programs side by side. The Amiga allowed to have multiple screens that were basically a better version of virtual screens combined with fullscreen mode.

Here is an example of somebody having Deluxe Paint open and the Workbench.

https://retrocomputing.stackexchange.com/questions/24842/ami...

The pinnacle of workflow design on the Amiga was of course ARexx which allowed applications to communicate through message ports and automation scripts.

Re: Playing Atari ST Music on the Amiga with Zero CPU

#44

Post by amiga386 »

makapuf wrote: post #37
bhaak wrote: post #26

Earlier quoted context omitted.

>> AmigaOS was a pre-emptive multitasking OS > Yes, but without memory protection. That’s why it was so fast. :) Also surprisingly stable all things considered.

I havent seen many desktop like workflows on it with several "big" apps open (and running cpu) at the same time, most ive seen was one software at a time or games. Cooperating with yourself is relatively easier, no ?

Having used AmigaOS, Mac OS, RISC OS, MS-DOS and Windows in the 1980s, I can say that Amiga definitely had the smoothest experience. Even the most basic things like reading/writing a floppy disk could make all but AmigaOS unusable. I remember thinking about Windows 95 "why is the mouse pointer juddery? It should never be juddery!" when trying to run several things at once.

The reason you don't see lots of "big" apps at once is because memory! RAM was expensive.

If you run a CPU-bound task on AmigaOS, you can use ChangeTaskPri on it, and you can easily see the difference. At its default priority of 0, the mouse pointer is still smooth but other applications start to clam up and starting new things is slow. Reduce the priority to -1 and everything's full speed again. Raise the priority to 5 and you'll have trouble moving the mouse pointer. Raise the priority to 20 and the system hangs...

I don't think you've truly experienced "cooperative" multitasking. Try RISC OS, which literally passes control around between applications and has to wait for them to give it back, unlike AmigaOS which will take it back from them. Any kind of error is an immediate modal window that stops the world. Accessing a disk stops the world. Pressing F12 on the desktop drops to a command prompt and stops the world. You can open a command prompt in a window but it runs at a fraction of the speed of the global command prompt.

Re: Playing Atari ST Music on the Amiga with Zero CPU

#45

Post by amiga386 »

rbanffy wrote: post #33
bartread wrote: post #28

Earlier quoted context omitted.

> Amiga made lots of assumptions about the use that ended up tuning it well to platform games and NTSC video editing, but nothing else. I think certainly it was used mostly as a games machine by most owners, but then again so was the Atari ST (at least amongst my cohort at school). As for tuning it well to games and video editing but nothing else... I don't agree. For a long time an Amiga 500 with 1MB RAM expansion a…

The Amiga’s heavy focus on TV-friendly timings went deep into the specialised chips to a point it was difficult to upgrade without losing compatibility. Because of that lack of modularity Commodore had to spend more resources to develop improved machines than its competitors. It was not an obvious mistake then, and it’s not clear now what they could have done to better compete with PCs and Macs. They could have made…

I think you're missing the elephant in the room. The IBM PC existed. That was it, that's all that mattered. Nobody got fired for buying IBM. Every computer for "business" collapsed because the IBM PC was here.

Macs only survived to the 1990s by hiding from the PC in a desktop publishing niche. Amigas and Ataris survived as games machines with multimedia capabilities. An Amiga that could not run Amiga games would basically be a Sun workstation. Businesses wanted IBM PCs.

Also, the "compatibility" was a two-way street. Amiga games banged the hardware directly and did amazing things on hardware of the time because of it, but that meant hardware-level compatibility for anything which came next otherwise it'd be the Amiga that couldn't run Amiga games. MacOS software was told not to touch hardware directly but go through the OS, and they did that, and thus all MacOS software was slow and ugly, and Apple still jettisoned compatibility anyway once they moved into the 1990s and started changing underlying hardware to PowerPC.

There's always the hypothetical that Commodore could have continued, but what really got them was that the nature of games changed. 3D was in, and they were still pushing 1980s arcade machine tricks. They weren't even thinking in that direction when along game Wolfenstein and DOOM pushing chunky pixels to VGA mode X, and the Playstation was just around the corner. I don't think just having a faster CPU, "VGA" and trying to appeal to business would have cut the mustard.

Re: Playing Atari ST Music on the Amiga with Zero CPU

#46

Post by [deleted] »

bhaak wrote: post #43
makapuf wrote: post #37

Earlier quoted context omitted.

I havent seen many desktop like workflows on it with several "big" apps open (and running cpu) at the same time, most ive seen was one software at a time or games. Cooperating with yourself is relatively easier, no ?

Remember that without memory protection everybody shares the same memory and everything is visible to every process. If a process doesn't release all their memory that memory leak will stay even if the process ended. Shared libraries were typically loaded only once into the system's single shared address space. Any process could potentially overwrite another task's memory or shared library state. I don't have my old…

[deleted]

Re: Playing Atari ST Music on the Amiga with Zero CPU

#47

Post by Tommix11 »

bartread wrote: post #28
rbanffy wrote: post #9

Earlier quoted context omitted.

> I really wish they'd crammed a SID chip into the Amiga alongside Paula This is something the Apple IIgs had. It had an extremely capable synthesiser with good graphics and performance capped so not to compete with Macs. It was a weird machine, a sharp contrast with the minimalistic Apple IIs that preceded, over complicated and trying to be too many things at once. For the same reason I prefer the design of the ST o…

> Amiga made lots of assumptions about the use that ended up tuning it well to platform games and NTSC video editing, but nothing else. I think certainly it was used mostly as a games machine by most owners, but then again so was the Atari ST (at least amongst my cohort at school). As for tuning it well to games and video editing but nothing else... I don't agree. For a long time an Amiga 500 with 1MB RAM expansion a…

I began my career as a graphic designer on the Amiga and Deluxe Paint series.

Re: Playing Atari ST Music on the Amiga with Zero CPU

#48

Post by z303 »

smokel wrote: post #10
ndsipa_pomu wrote: post #4

Earlier quoted context omitted.

I don't know if the Amiga was ahead of its time or the PC was behind its time. AmigaOS was a pre-emptive multitasking OS whilst PCs had to wait for Windows NT/95.

There were early multitasking operating systems starting with the 286, but for demos you'd typically use the entire CPU. Part of the magic was that video routines would run at an extremely constant 50 (or 60) Hz, perfectly in sync with the hardware. This, and color bleeding, resulted in a buttery smooth experience, that I still miss. One particular example of this experience was that you'd use "raster bars" to time t…

An example: https://youtu.be/z2C1uVqCqME

Green is the main music routine. Blue is the sample playback

Re: Playing Atari ST Music on the Amiga with Zero CPU

#49

Post by z303 »

smokel wrote: post #10
ndsipa_pomu wrote: post #4

Earlier quoted context omitted.

I don't know if the Amiga was ahead of its time or the PC was behind its time. AmigaOS was a pre-emptive multitasking OS whilst PCs had to wait for Windows NT/95.

There were early multitasking operating systems starting with the 286, but for demos you'd typically use the entire CPU. Part of the magic was that video routines would run at an extremely constant 50 (or 60) Hz, perfectly in sync with the hardware. This, and color bleeding, resulted in a buttery smooth experience, that I still miss. One particular example of this experience was that you'd use "raster bars" to time t…

and any example of a zero bitplane demo. Just using the CPU to switch the background colour

https://youtu.be/z2Ke-Irp7U8

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