What makes the OS for QL any better, different, unique ?

A place to discuss general QL issues.
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SinclairSociety
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What makes the OS for QL any better, different, unique ?

Postby SinclairSociety » Mon Apr 15, 2019 11:58 pm

From those that know the QL well... what to you males the OS that came with the QLs any better, different, or unique compared to other flavors of OS on other platforms.

I have heard a comment before that the OS is better... but curious what that means. Something that can back that up?

I don't know the QL OS (QDOS) yet so was curious others opinions as I journey into the QL.

TJ


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dex
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Re: What makes the OS for QL any better, different, unique ?

Postby dex » Tue Apr 16, 2019 12:15 am

For me it is simply "the Unix for the rest of us".
Simplicity and imminence of Basic combined with power of all that multitasking, networking, pipes, windows, ...


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SinclairSociety
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Re: What makes the OS for QL any better, different, unique ?

Postby SinclairSociety » Tue Apr 16, 2019 12:21 am

dex wrote:For me it is simply "the Unix for the rest of us".
Simplicity and imminence of Basic combined with power of all that multitasking, networking, pipes, windows, ...


So in general terms, do you feel QDOS is easier to grasp for a commoner like me versus learning Linux or Unix?

TJ


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Re: What makes the OS for QL any better, different, unique ?

Postby Dave » Tue Apr 16, 2019 12:30 am

Oh, yes.

Absolutely.


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Peter
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Re: What makes the OS for QL any better, different, unique ?

Postby Peter » Tue Apr 16, 2019 7:00 am

Although the QL came earlier than ST and Mac, the multitasking scheduler was already preemptive - technologically superior to the cooperative multitasking of the other machines, where every program could block the whole system.

The ease and power of networking was amazing, you could access windows, filesystems and peripherals on remote machines with a few BASIC commands.


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Re: What makes the OS for QL any better, different, unique ?

Postby Pr0f » Tue Apr 16, 2019 7:49 am

For me the extensibility of QDOS and it's partnering BASIC.

Although it lacks protective memory management, it does offer methods to allocate and deallocate memory and mechanisms to link blocks of memory for jobs and drivers.

At the time it came out the QL was ahead of the curve and hampered only by some cost cutting hardware choices, which come back to bite us time and time again. That being said, I think it's created a group of people who have had to stretch to get the most out of the platform. Would we have had Linux without the QL ?


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Re: What makes the OS for QL any better, different, unique ?

Postby janbredenbeek » Tue Apr 16, 2019 9:04 am

Pr0f wrote:Would we have had Linux without the QL ?

Maybe not, since Linus Torvalds has written programs on the QL, including an assembler and editor (according to Wikipedia). I wonder if they're still around somewhere.

Jan.


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Re: What makes the OS for QL any better, different, unique ?

Postby Arnould » Sat Apr 27, 2019 1:22 pm

Hello @SinclairSociety

I had the same question back in the beginning of the 90's, 25 years ago. I contacted Tony Tebby who just moved to France. And he explained to me during months, because I am not a computer scientist, why QDOS/SMSQ is different, maybe better.

It has to do with semaphores. Edsger Dijkstra proposed them in the 60's in his very famous dining philosophers problem (not a joke, look for it in wikipedia) for multitasking/parallel computing. They are now universally used in all so called OSses. Semaphore is quite long to write so they are maybe better known under the name "lock" especially in the Linux kernel development mailing list. Maybe 10 years ago I made a search in this mailing list on this word. From memory I found that about 15% of the problems in the Linux kernel are directly related to these locks. And maybe many more indirectly, who knows? These locks are used to protect data from concurrent accesses in a multitasking environment. But they are linked to all sorts of problems in the task/thread waiting list when those tasks/threads become blocked (same for OSses based on client/server architecture). See for example "deadlock" and "priority inversion" to name a few.

Nothing like this complication in QDOS where there are only atomic operations to protect data structures from concurrent accesses. This brings smaller problems which, according to Tony, could all be solved in a rewrite, eg the atomic access to storage memory: in QDOS you, the user of the system, has to wait until a file is read/saved/copied completely. But it gives a much more stable development environment.

This is computer scientist jargon that no manager in the world can understand. Thus I wrote a paper in English in 2007 for my employer, a well known industrial robots manufacturer, after I tested a simple analogy with my son who was aged 12 and because he perfectly understood the problem and Tony's cure. This is quite old, and as no one was interested (I was fired during the 2009 crisis), if you insist, I can copy it in here..

Arnould, France


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Re: What makes the OS for QL any better, different, unique ?

Postby Pr0f » Sat Apr 27, 2019 4:12 pm

I Remember semaphores from programming in Assembler on an old IBM Mainframe.

They were really useful for controlling program flow across multiple running batch programs, where one would need to wait on another.

The 68000 assembler has the test and set instructions if you want to roll your own ;-)

Wait, Post and Clear. The IBM ones also returned the address of the semaphore you were waiting on by name, which meant you could pass messages using a pair of such constucts, by having your own writeable area just after the semaphore


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Re: What makes the OS for QL any better, different, unique ?

Postby Derek_Stewart » Sat Apr 27, 2019 7:16 pm

Hi,

Multi-tasking...

So Minera or SMSQ/E


Regards,

Derek

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