How to architect a game like Jet Set Willy

BitNaughty

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Dec 27, 2009, 8:52:51 AM12/27/09

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I'm curious as to what this group thinks about the said topic.
Specifically, how would you make sure that that many things were
happening on screen at the same time. We need to use the Speccy's
interrupt system to maximum advantage, no? (i.e. IM2). That's what
methinks, I need to know if I'm on the right path.

Thanks,

BitNaughty.

spi...@freenet.co.uk

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Dec 27, 2009, 9:19:24 AM12/27/09

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And verily, didst BitNaughty <bit-n...@hotmail.com> hastily babble thusly:

The interrupt system isn't necessary for that kinda thing.
It's only necessary for things that happen INDEPENDENT of the game code
itself. The main game loop could handle all the moving things on the screen.
--
| spi...@freenet.co.uk | Windows95 (noun): 32 bit extensions and a |
| | graphical shell for a 16 bit patch to an 8 bit |
| Andrew Halliwell BSc | operating system originally coded for a 4 bit |
| in |microprocessor, written by a 2 bit company, that|
| Computer Science | can't stand 1 bit of competition. |

OwenBot

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Dec 28, 2009, 6:05:01 PM12/28/09

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I'd just use the JSW engine. And it doesn't use interrupts at all
which is why the music gets progressively worse.

BitNaughty

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Dec 29, 2009, 9:24:18 AM12/29/09

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On Dec 29, 4:05 am, OwenBot <cheve...@gmail.com> wrote:
> I'd just use the JSW engine. And it doesn't use interrupts at all
> which is why the music gets progressively worse.

Sorry - what's that?

....but I'd really prefer to code the whole thing on my own, not
taking help from any engine or anything. Any Speccy game programmers
who hang out on this forum want to contribute?

OwenBot

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Dec 29, 2009, 3:33:38 PM12/29/09

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This isn't a forum. This is usenet. The programmers have all been
decanted into WoS.

Matthew Westcott

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Dec 31, 2009, 7:10:41 AM12/31/09

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OwenBot wrote:
> This isn't a forum. This is usenet. The programmers have all been
> decanted into WoS.

Not all of them.

Anyway, Spike is right - it's all done within one overall game loop.
It's not a case of each sprite running in its own routine, running
concurrently through interrupts - it's just a single routine that looks
at each sprite in turn, checking its position and moving it by a pixel
or two, and then going off and doing the other tasks like keyboard
scanning and collision detection, then looping around again.

Also, I don't think the music going out of tune has anything to do with
using / not using interrupts - it's just that the method used for
transposing the music down every life is a bit rough-and-ready.

Chupo

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Jan 1, 2010, 7:48:27 PM1/1/10

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In article <1637f36c-b308-4131-a65c-858bf2ca362f@
15g2000prz.googlegroups.com>, BitNaughty <bit-n...@hotmail.com>
says...

Here you can find the whole disassembly od Manic Miner:

http://www.seasip.demon.co.uk/Jsw/manic.mac

so you can get a preety good idea on how something could be done.
--
Merry X'mas&a happy New Year!
Chupo

OwenBot

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Jan 3, 2010, 8:49:10 AM1/3/10

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On Dec 31 2009, 12:10 pm, Matthew Westcott <gas...@raww.org> wrote:

[snip]

> Also, I don't think the music going out of tune has anything to do with
> using / not using interrupts - it's just that the method used for
> transposing the music down every life is a bit rough-and-ready.

I was quoting from the man himself. But I can't remember which
interview I read it in.