Saturday, February 11, 2017

Resurrecting an old computer

Well….almost!

Ok these screengrabs are from an emulator. But what you are looking at are screengrabs from Arthur 1.20 - if you’re not sure what that is it’s the precursor to Risc OS. This old OS ran on an equally old computer called the Acorn Archimedies. And it dates from the late 80s — remember, this is the era of the Amiga and Atari ST way back when they were in their heyday and the games machines of the moment.

But the old acorn machine used something which is still around today, namely the ARM CPU. If you have an android phone it more than likely has an ARM CPU inside. And I remember using this OS and that old acorn machine in my last few years at school. So I sort of got to use the very first ARM based computers! But what on earth did this early OS - arthur OS look like? Well, here goes!

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This is the starting screen of arthur. A Blue desktop and icons for the floppy drive, colour palette, notepad, diary, clock, calculator and exit. The odd looking mouse pointer is some sort of bugette in the emulator.

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Clicking on the floppy disk icon opens a new window with some directories present.

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But I’ll come back to those. Let’s try the colour palette. Note that “bor” changed the border colour and Ms1/2/3 changed the mouse colour.

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The built-in notepad. Note that it turns red once you type text into it.

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…and here are your options for notepad. Load, save and print. That’s it!

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The diary program. For some odd reason, arthur OS thinks it is 1997(!). Note that clicking on a day lets you start a simple diary.

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The clock and calculator.

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Going back to the window we had open earlier. Let’s open the “apps” directory.

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…but before that, you *can* display the files as a list. But only icons or as a list. Nothing else!

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Loading up one of the apps, here’s “ARM Paint”. It’s pretty basic — Dpaint 3 on the amiga it ain’t!

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Arthur OS also includes some demo programs. Here’s one that describes graphics and the various screenmodes.

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Another demo to do with the keyboard has a similar look.

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Rather intrestingly, Arthur OS comes with a demo version of a game (”Zarch”). This runs a *lot* faster than the Amiga and ST versions (”Virus”).

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Back to the desktop - but whappens if we hit “Exit”?

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….this is the answer - a command line!

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And it even has a version of BASIC all ready to use. The acorn machines were unusual in having a basic interpreter built into a 32-bit system, let alone one using an ARM CPU!

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Quick and dirty basic program

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You can even use the older BBC Micro screenmodes. This is “MODE 2” - 160×256(!).

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It even has “Teletext” mode built in (MODE 7)!

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….or alternatively you can use rhis simple text editor (which even creates the line numbers for you) in basic!

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If you change screenmode this is what you’ll probably see — the default in BASIC/Command line is white text on a black screen.

Hope everyone enjoyed that!

SP