Amiga Multitask

[commodorejohn]

The Amiga 1000 looks nice. Don't forget you have to load the OS first, no rom.

You had to load Kickstart, but it did have a ROM, or they'dve had to include a front panel for you to toggle the loader in with ;P

[commodorejohn]

I've had more crashes (program and system) on Windows 3.1 than I've ever had on AmigaOS...

[commodorejohn]

If it had virtual memory you could actually run paint program and word processor at the same time. So it is actually an OS limitation.

I'm trying to imagine a virtual-memory system on 8MHz and 28 KB/s floppy disks, but I can't think over the screaming in my brain. I think there may be a lesson in there somewhere.

[commodorejohn]

Indeed. For proper multitasking you needed more memory and fast hard disks...

Alternatively, you could just have efficient software that maximizes free memory for your actual work purposes and enough RAM to fit the task at hand, rather than churning data to and fro over a disk interface many orders of magnitude slower than the RAM which is itself likely not actually fast enough to keep up with the demands of the processor.

But, you know, that'd just be crazy.

[commodorejohn]

True enough - no existing system is an ideal system. Still, I'd place more stock in good coding than hacky disk-swapping any day.

[commodorejohn]

Remember, UNIX was originally developed on a DEC PDP-7 to multiuser+multitask in 1969; The PDP series (oddly they were 18-bit'ers) had had a very similar instruction set with the MOS 6502

Actually they were all over the place, with (off the top of my head) 12, 16, and 18-bit offerings of quite varied designs. (18-bit actually wasn't odd at the time, quite the opposite in fact; I'm not sure exactly where it comes from, but I expect that for scientific purposes having an integer range that encompassed all the way from +99,999 to -99,999 with room to spare made it easy to think of "five-digit integer capability" or somesuch.)

The PDP-11 was actually a big influence on the design of the 68000; you can thank it for the Amiga having a decent complement of truly general-purpose registers instead of the 8086's frol-de-rol with A, B, C, and D all being able to do different overlapping but never identical sets of things...

[commodorejohn]

Some software needs alot of ram because of the functionality it offers. The only compromise you can make here is to remove functionality, but then there would be no innovation.

Sometimes this is true, yes - but very rarely compared to the number of applications that just plain take way more than they need.
 

Some uses more than it should because writing perfectly efficient software is alot more expensive & ram is cheap. The only compromise you can make here is delay the software and charge more for it, the odds are the developers would run out of money.

Writing perfectly efficient software is one thing, but these days most developers don't even try. There are text editors now that take up 10-20MB just sitting idle with nothing open. That's inexcusable. It's not even that nobody hand-optimizes software anymore, hardly anybody even designs for efficiency on any level these days.

Also RAM is only cheap by comparison to how it used to be. Any money you have to spend upgrading a computer that would otherwise suit your needs perfectly well because bloaty software is thrashing the disk is not "cheap" by any measure.
 

Oh, don't go there..
The "swap or not swap" arguments in the Linux kernel threads are epic...

This absolutely baffles me...sometimes you do have no choice but to rely on disk swapping, but it is so monumentally inefficient that I can't even begin to fathom why you would not avoid it whenever possible...

[commodorejohn]

Only 20 MB? Must be efficient program. I just launched Word and it is taking over 40 MB right after launch. I am not sure if there is anything what good old Kindwords couldnt do? :-)

Well, "text editor" is not the same thing as a full-fledged formatted word processor, but I won't argue that the point is just as applicable to your examples

[commodorejohn]

You think it's inexcusable, but you have a rather extreme point of view.
 
If you work in software development and aren't lucky enough to work for a billionaire that is as obsessed with efficiency as you are then you'll end up having to make tough choices.

I do work in software development, and I do it backend, on processes only the IT staff will ever use once per day, for a company that pays me the same in any case and only cares whether things are up and running on-time. Even so, I at least put some kind of thought into making things reasonably efficient and not a huge waste of memory and CPU time. Someone designing software that many people will use multiple hours a day should be putting even more thought into designing software that's light and responsive and not bloaty crap, not less (and that goes for the companies behind them, too.)

[commodorejohn]

Well, that's basically the problem, isn't it? Software companies (or, actually, pretty much all companies, these days) have zero interest in actually providing quality anymore except insofar as it can be used to justify a higher price tag, because the whole pirahna-pool atmosphere of the modern business world sneers at the idea of pride in a job well done, let alone any other reason for doing anything than making the most money with the least expenditure of effort possible. It's a disease...

[commodorejohn]

There's nothing about the x86 architecture that prevents it from doing decent multitasking, even in the larval 16-bit phases. It's just that nobody did it well until way later, for stupid reasons.

[commodorejohn]

But by the mid/end of the nineties it already showed its age: no RTG/RTA (yes: Windows 3.11 was more advanced in that regard), no memory protection, no virtual memory, not portable,... And despite mostly a rewrite (OS4/MOS/AROS), this hasn't changed. There is RTG/RTA, but that's it. Most big technical limitations are there...

What exactly does "RTG" stand for here? Certainly not "ReTargetable Graphics," it definitely supported that at least from WB3.1, with drivers...

We all agree it was impressive 27 years ago. But time has changed. Windows isn't based on DOS anymore.

You're right. Windows is no longer based on DOS, which was based on CP/M, which was based on RT-11. Windows is now based on VMS. So we have moved ahead one generation of DEC minicomputers and snapped back a couple levels of indirection to go from a Windows based on an OS from 1971 to a Windows based on an OS from 1975, while the rest of the modern computing ecosystem congratulates itself for being based on an OS from 1969. PROGRESS!

However decent multitasking is a matter of opinion. While I loved the Amiga, the lack of memory protection was a huge downside. Especially if you're developing software, as it's more likely to crash. It wasn't until I started using Windows NT that I realise how useful memory protection was.

I won't argue that memory protection is hugely useful, but it's not an absolute requirement. And anyway Iggy was talking about the 8086 in comparison to the 68000 and 6809, neither of which featured protected memory either.

[commodorejohn]

BTW I had an MPM machine (got rid of it).
I thought those were Z-80 powered.

They were. (Though I don't know if, like CP/M, there was a 68k variant.) MP/M was brought up in the context of "what if QDOS had been based on that instead."

[commodorejohn]

95 was a huge advancement over 3.1, but it was sorta only halfway to NT, so it wasn't particularly stable as a result. Light as hell, though, for modern 32-bit Windows. 98 and 98SE were heavier by quite a bit, but also much stabler.

2000 I've been playing around with, and I'm quite impressed at how light and responsive it is, and solid as a rock; I wish this had been the OS that took off and gained popularity rather than XP, then there'd be better, newer hardware I could run it on.

[commodorejohn]

Also people always say Win2000 is better than XP but unless you only had 64mb (a paltry amount in 2002 when XP was in use) it booted faster and thrashed the disk a lot less than 2000 on all the 100s of laptops I tried it on over the decade of sales of computers and laptops I managed. Don't ask me why.

I've been using Win2K on a 1GB Pentium III laptop for several months now, and it doesn't thrash the disk in the slightest. I could probably even turn off paging entirely, come think...