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Author Topic: Xenon 2 on Enterprise (Read 4574 times)

Offline Saint

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Xenon 2 on Enterprise
« on: 2012.October.03. 10:40:45 »
Has anyone thought what Xenon 2 might look like on the Enterprise?

A bit like this (proper enterprise palette @ 160x200) --

8153-0

Now to find the time to do it. With hardware scrolling and being able to change the screen address at any line, this should be relatively easy to do the full-screen vertical scrolling. Which is something that wasn't possible on the old STFM...

James
« Last Edit: 2012.October.03. 11:08:30 by Saint »

Offline Pgyuri

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Re: Xenon 2 on Enterprise
« Reply #1 on: 2012.October.03. 12:15:36 »
Hi Saint,

This game was one of those games what I could finish on PC (in 1991). Excellent game :)

I'm afraid it would be hard to port to Enterprise. AFAIR there was extremly huge spaceship when you collect all items. This game was too hard to Enterprise (Z80 is too slow to moving large memory block). You are right, the vertical scroll is easy on EP but don't forget you have to clear all sprite (spaceship, laser,s bullets, rockets, etc.)  from the screen before scroll the LPT table or you will see many ghost.

I like these 'fire-to-kill-everything' games but they should be fast. I think EP can't solve this problem only if you make compromises but that's not Xenon 2, just like something same.

Pgyuri

ps: worth to try in DosBox ... you can finish without cheat almost in 2-3 weeks ...

Offline Saint

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Re: Xenon 2 on Enterprise
« Reply #2 on: 2012.October.03. 12:24:33 »
Hi Pgyuri,

I was thinking 128K only, using double buffering and running at 25fps.

Also, I've been thinking about using "compiled sprites", which are the fastest way to draw sprites on Z80. So you have a routine per sprite which directly loads values from constants and writes them to VRAM.

I have also been thinking about a cunning way of reducing CPU load for removing old sprites. You basically keep dirty block regions and only replace those regions which aren't going to be overdrawn by sprites again.

However I've not done a lot of Z80 as I've always been a 68000 guy, so it'll be interesting to see how slow this all is! :)

And as a final resort, when I get my Enterprise on and FPGA running, I'll add some hardware sprites through the EC0-3 inputs.

Still amazing to see what the Enterprise was capable of displaying in terms of graphics. What it could move around the screen is another thing, though... :)

James

Offline Zozosoft

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Re: Xenon 2 on Enterprise
« Reply #3 on: 2012.October.03. 12:50:24 »
If not too fast then it is not problem :-) I always hate these games because too fast for me  :oops:
(Who can got the Lost Viking Achievements in the Starcraft 2???)

Offline Saint

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Re: Xenon 2 on Enterprise
« Reply #4 on: 2012.October.04. 09:50:03 »
Has anyone got some sample code to setup Nick to display a screen?

Thanks!
James

Offline Zozosoft

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Re: Xenon 2 on Enterprise
« Reply #5 on: 2012.October.04. 11:15:33 »
Has anyone got some sample code to setup Nick to display a screen?

There is my sample "barebone" example program. This is allocating memory, first 48K for the program, last 16K for video, setting up 320x200 4 colors screen. Including proper memory allocation and exit routine.

I tryed translating the comments, I hope you can understood it  :oops:
« Last Edit: 2012.October.04. 11:21:27 by Zozosoft »

Offline Saint

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Re: Xenon 2 on Enterprise
« Reply #6 on: 2012.October.04. 11:18:13 »
That's perfect, thanks!!  :ds_icon_cheesygrin: