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Ars Technica Reviews AmigaOS 4.0
Amiga Lover writes "While tales of the troubles behind the Amiga's ownership abound over the last 10 years, work has been going on in the background for newer releases of the operating system that powered some of the most desirable computers from the 1980s. You can now buy brand new Amiga motherboards, and the operating system is very close to a final release. Jeremy Reimer from arstechnica reviews the current developer preview of AmigaOS 4.0, going over this new small and fast OS in thorough arstechnica style."
While I loved my Amiga in the day, I can't justify spending $1375 for a G3-800 system basd on the new Micro systems.
This is from softhut, but I don't want to direct link since it is slow anyway:
AMIGA ONE PRECONFIGURED SYSTEMS
Micro A1 System:
First True Luggable / LAN Boy Amiga System !!
See Case Images
Micro A1-C Motherboard with OS4
750fx G3 Processor @ 800MHz
Built-In Sound
80GB 7200RPM Hard Drive
DVD/CDRW Combo Drive
2 USB Ports, 10/100 Ethernet
Keyboard and Mouse
------ $ 1375.00
All completely installed, tested and ready to run
i used to own an a1200. it still feels more responsive than any computer that i've had since. you can get groovy snapshots and news at http://amigaworld.net/
AmigaOS has had preemptive multitasking since day 1 back in the 1980's.
Memory protection is another matter, it's not there as Linux users would expect it to be, no. It's a highly desired feature of course, but implementing it properly is an issue as it conflicts with some fundamental aspects of AmigaOS arcitecture. We want it, and it will likely happen someday, but current priorities fundamentally revolve around getting the OS ported to PowerPC native and getting it to run on new PowerPC motherboards, porting the 680x0 assembly to C, involving a great deal of "classic Amiga hardware" dependencies, as none of that hardware is present on new motherboards.
Once the fundamental porting is done then it will be time to look at rearchitecting things to allow memory protection, multiple users (it's currently a single-user OS so no user or group file or directory protection concepts). I don't know what all the project managment has in mind for adding such features, but users and developers do want them.
[removed question about true multitasking and memory protection]
;)
Amiga OS had both those in 1985, IIRC.
No, you don't remember it correctly. Amiga OS had true, preemptive multitasking in 1985, but it doesn't have memory protection to this day. Nor does it have virtual memory, or makes any other use of MMU present in every modern processor.
Yes, you could install Enforcer notifying you about writes to system memory, or VMM permitting swapping to disk in case the real memory is exhausted. But both these programs weren't part of system and lost of programs crashed when they were present and running. I remember having exceptions list in VMM longer than... certain body parts of pr0n stars
Other than that, Amiga OS was quite remarkable piece of software at that time with certain solutions still not duplicated in today's operating systems.
Robert
Bastard Operator From 193.219.28.162
anon coward 1:
RTFriendlyArticle. For memory protection they've done the same thing as Apple did and what PalmSource will soon have to do. And they always had true multitasking.
anon coward 2:
And what is that?
RTFA: a virtual machine a la classic mode for legacy apps, mmkay.
From tfa:
Hyperion realized that with the current state of the Amiga applications market, asking developers to write for a completely new operating system was unrealistic. After all, if you are going to do that, you might as well write for the Windows market and have your old users run old Amiga applications in an 68k Amiga emulator such as the excellent WinUAE. Instead, Hyperion decided to rewrite the old Exec kernel from AmigaOS 3.1 in PPC code, supporting virtual memory and memory protection, but leave the memory protection features turned off by default. This allows application developers to easily port their old 68k Amiga apps to PPC and 4.0 native code, often with a single recompile. The current plan is to introduce memory protection for OS4 apps in version 4.1. However, the kernel can watch for illegal memory accesses and when it finds them, it displays a "Grim Reaper" dialog that allows the user to kill the offending application.
Legacy Amiga applications, such as games, that were written to access the old custom chipset hardware directly, will not run in OS4.0. However, a port of WinUAE for OS4, called E-UAE, has been produced that will allow these games to be run as well. So-called "system friendly" legacy Amiga applications, the kind that were able to use PC-based graphics cards, run directly from the OS4 shell. The operating system launches a 68020 emulator seamlessly in the background when the application's icon is double-clicked. In this release of the OS, the emulator is interpretive only, and provides the speed of about a 50MHz 68040 on the 800Mhz AmigaOne hardware.
music lover since 1969
Is that the same Atari ST that had a faster processor than the Amiga. :)
No, it didn't. It had co-operative multitasking, just like MacOS and RiscOS and ProbablyOtherOS, which is why when it crashed it took the whole system with it.
Wrong, it did have preemptive multitasking, but this has nothing to do with a crash bringing down a box.
It (the 68000 processor) had no way to run individual programs in their own, protected address space. So program A can quite happily write to memory being used by program B.
In both respects it's similar to Windows 98.
Again it seems like its time to mention AROS. Its Amiga like, it has less features, less applications, it looks bloody similar, but, its open source. I feel if the future of Amiga lovers lies anywhere, it'll be here. It wont happen over night, but it will happen (if there is an amiga future).
Giving IE users a taste of their own medicine since 2005 - http://pods.-is-a-geek.net/
Ahem, first line from the RKM: Libraries (Commodore, Inc. 1992), page 2:
"The Amiga uses preemptive multitasking.. "
No sweat. =)
You can buy a Catweasel. Or alternately, you can pop on eBay and snag an old Amiga for about 50 bucks. Find a Fred Fish disk with a terminal program...buy a null modem cable and move the files over.
Currently that's what I do. I DMS a disk into a file, and then null-modem it to my laptop. WinUAE runs 99% of the images I make that way.
Hope that helps. BTW, my Amiga 500 was my first C programming experience too. Aztec C. Loved it.
Weaselmancer
rediculous.
Cloanto also offers a data transfer service if you don't want to buy a new piece of hardware for a limited data transfer job.
My own uses for AmigaOS:
email
web browsing
word processor
read PDF docs
software development
file managment (including PC folders via samba as Windows explorer sucks rotten eggs)
games
Wow, that sounds a lot like what some people might use Linux for, doesn't it?
It's a matter of choice. Why should my choice be wrong for me, yet your non-Windows choice is right for you?
AmigaOS is a microkernel; drivers run as tasks separate from the kernel. So it's just a case of running a GPLed program on a non-GPLed operating system.
-Stephen
In 1985 the A1000 blew everything out of the water. I still have my A1000 in a box somewhere. One of the coolest PCs ever built the entire team signed the inside cover (including Jays dog).
Processor:
An 286 was state of the art and the 68000 compared more than favorably.
Graphics:
Heck EGA was just recently introduced, Macs were monocrhome. Amiga had extraordinary high colour capability (up to 4096 colours IIRC) and custom co-processor to accellerate 2d operations
Sound:
A basic PC beeped. The first soundblaster was still 2 years away. The amiga had multichannel digiatal waveform sound with co-processor support.
OS:
PC had Dos or Windows 1.0 (steaming pile of dung).
The amiga had a small efficient GUI OS with true pre-emptive multitasking...
The Amiga was a revolution of HW and software. What killed it was stagnation. It remained relatively unchanged for years allowing competition to catch and surpass some of its basic specs.
Personally I moved on when Win95/OS2 VGA/ 486/ Soundblaster finally made PCs tolerable.
OS4 is going to have virtual memory. But it wont have full memory protection yet, due to backwards compitability with 68k apps. I believe better memory protection will come in next release"4.1" if there are any.
Amiga OS had true, preemptive multitasking in 1985, but it doesn't have memory protection to this day. Nor does it have virtual memory, or makes any other use of MMU present in every modern processor.
AmigaOS 4.0 includes functionality for virtual memory, paging, etc. Memory protection is optional for OS4 native applications, but will be a feature in a forthcoming version I'm sure, once enough software has been ported/created natively.
And as the review said, AmigaOS actually made computing fun and enjoyable, and it seems the current version does as well. It is a shame that some software is way behind, especially web browsers, but that will probably get fixed one day.
Why would they have to license the entire OS under the GPL because the shipped a GPL'd driver with it?
Oh, they wouldn't. They'd just have to release the code that they added to the driver.
Vintage computer games and RPG books available. Email me if you're interested.
I suggest you take computer science 101.
The Amiga had preemptive multitasking. It forced a context switch unless you where told it not to. Usually when closing a port. To keep the system stable an Amiga program had to fetch all the messages that it might have waiting at a port before closing it so you would tell the OS not to switch tasks while you did a fast tight loop to fetch the messages until it was empty then close the port. Guess what I used to program the Amiga. You are confusing preemptive multi tasking with memory protection. The Amiga lacked memory protection one of it's big mistakes IMHO. A good example of an other preemptive multitasking os without memory protection is ucLinux. ucLinux often runs on CPUs that lack the MMU hardware to do memory protection. The Amiga was better than anything from Microsoft until Windows NT or maybe 95 if you are feeling kind.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
Having swap in RAM defeats the entire purpose of having swap space in the first place.
Several virtual memory management apps were written for the larger of the classic Amiga's and worked fine, but most of the time we made do with a few MB of memory and the lack of a vmm was rarely an issue.
As a couple of Anonymous Cowards have said, the T-shirts have shipped. Maybe when I get home I'll actually try digging my Amiga out of the cupboard and see if it still works (the 1084 monitor does, it's being used with a Playstation). I might even get as far as making a ROM file and playing with UAE sometime, and/or AROS.
But buy a new Amiga? What for?
rant
> Nor does it have virtual memory, or makes any other use of MMU present in every modern processor.
AmigaOS 4 DOES have virtual memory built-in. This can exist without memory protection features, which are not present in the form that Slashdot readers would recognize it. There is some limited memory protection of kernel-space, but nothing in user-space.
There HAS been use of the MMU in the past. Mostly development stuff, debuggers and whatnot. The old VMM virtual memory tool you mentioned, which added VM to the older OS, used the MMU.
Elbox used it for their Mediator PCI bus drivers for the Amiga 1200. The mediators for other Amiga models did not use it, but the A1200 computer only provided 24bto address lines for them to use. The 3000 and 4000 Amiga models provided all 32bit address lines. For the drivers on the A1200, they used an 8MB (or 4MB depending on jumper settings) window, and they in more recent versions fo their software use the MMU to keep track of where the drivers are going and can automatically map the window to the proper addressing fo rthings to work, as if the driver was talking down a full 32bit address bus. www.elbox.com
A small number of poroductivity apps had a minimal sort of virtual memory features built-in to them as well, and required MMU to run.
2) The speech synth chip.
There was no speech synth chip.
The speech synthesis in 1.1 through 2.04 was done in software, via a license from another company.
The license ran out by the time AmigaOS 3.0 was released, so the A4000 and A1200 never had native speech synthesis (although you could just copy it from a 2.04 or 2.1 release.)
Basing Mac OS X on UNIX worked because there wasn't anything to the old Mac OS that was worth saving, except the applications, and they were able to transit the applications to a new OS reasonably cleanly over years WHILE maintaining sales wit hthe old OS.
This is a completely different situation. The old Amiga OS was the closest thing to a real-time microkernel desktop environment that's ever been released to the general public: QNX dropped out of a retail version of Photon, and the only other candidate, OS/9 (no relation or Mac OS 9) on the Radio Shack color computer long predated anything like a desktop OS. If Amiga went that way, well, they would just be another Linux distro... and one that didn't run a lot of important Linux software because it's not an 80x86 and so it won't run binary-only packages.
I'm amazed that this seems to have maintained almost everything that was good about AmigaDOS, including the wonderful infinitely configurable message-passing OS architecture. Until this moment I had written off AmigaOS as another doomed Linux clone. It may be doomed, but if so it's doomed with style.
Part of the *nix philosophy I believe is interoperability and choice provided by source compatability, the ability to compile software on any OS that complies with POSIX and other unix standards.
I ran the Amiga sources newsgroup for some years, and did several ports of UNIX applications to the platform. Even back in 1986 it was already a very UNIX-friendly and UNIX-compatible environment. I can't imagine that it's moved away from that since.
they need to support POSIX, X11 and other Unix source compatability standards
The first web browser I ever used was UNIX Mosaic, running on my Amiga using a local X11 server from a UNIX box running at my ISP. The text editor I used was "elvis", one of the classic "vi" clones, and porting it to AmigaDOS was almost trivial compared to what I'd had to do in other ports.
This is why we see so many different filesystems avialable on Linux for instance
The Amiga had user-written user-mode file systems, including some amazing ones like a RAM based file system that survived reboots, long before Linux existed. The Amiga API is VERY well designed for this kind of thing... and needless to say no applications had to be rewritten to make it work!
This is nothing but good news. Please do some research before dismissing this amazing OS because it's not based on Linux.