Woot! Finally managed to get to the bottom of this nasty bug. Visually, the solution is a tiny bit inelegant—the guy bounces slightly off the top of the screen—but, hey, the game no longer crashes!
Up for grabs at the usual place.
Exolon Crashing Bug Fix (when you jump too high)
- Ast A. Moore
- Rick Dangerous
- Posts: 2640
- Joined: Mon Nov 13, 2017 3:16 pm
Exolon Crashing Bug Fix (when you jump too high)
Every man should plant a tree, build a house, and write a ZX Spectrum game.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
- Alessandro
- Dynamite Dan
- Posts: 1908
- Joined: Wed Nov 15, 2017 11:10 am
- Location: Messina, Italy
- Contact:
Re: Exolon Crashing Bug Fix (when you jump too high)
I never stumbled into this bug actually - but thank you for fixing it
- Ast A. Moore
- Rick Dangerous
- Posts: 2640
- Joined: Mon Nov 13, 2017 3:16 pm
Re: Exolon Crashing Bug Fix (when you jump too high)
Yeah, I thought it was pretty rare myself, but then I noticed I could trigger it every time on a multitude of screens (including some of the very early ones):
And my fixed version:
And my fixed version:
Every man should plant a tree, build a house, and write a ZX Spectrum game.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Re: Exolon Crashing Bug Fix (when you jump too high)
This is great, I really like your fixes.
Did you possibly try to analyze Dynamite Dan II and missing ending issue?
We discussed this on wos long ago, but still i'm not sure why the game can not end in the way described in the manual.
After all, it might be good to make at least a congratulations message if there was any free space at all.
Would it be possible to do such a fix?
Did you possibly try to analyze Dynamite Dan II and missing ending issue?
We discussed this on wos long ago, but still i'm not sure why the game can not end in the way described in the manual.
After all, it might be good to make at least a congratulations message if there was any free space at all.
Would it be possible to do such a fix?
- Ast A. Moore
- Rick Dangerous
- Posts: 2640
- Joined: Mon Nov 13, 2017 3:16 pm
Re: Exolon Crashing Bug Fix (when you jump too high)
Thank you!
No, I haven’t looked at it. I didn’t play it much back in the day, so I’m not familiar with it.Pegaz wrote: ↑Sat Feb 02, 2019 11:41 amDid you possibly try to analyze Dynamite Dan II and missing ending issue?
We discussed this on wos long ago, but still i'm not sure why the game can not end in the way described in the manual.
After all, it might be good to make at least a congratulations message if there was any free space at all.
Would it be possible to do such a fix?
I generally try to make minimal changes to the originals and—whenever possible—preserve the original loaders (which is particularly easy with some of the strongly encrypted ones). Often, there’s is barely enough room for even a simple fix. Exolon is a good example, actually. It’s very tight and I barely managed to find a few spare bytes.
But I’d be happy if someone pointed me in the direction of some compendium of known bugs in Spectrum games. The games that I provide fixes for are for the most part the ones I discovered personally.
Every man should plant a tree, build a house, and write a ZX Spectrum game.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Re: Exolon Crashing Bug Fix (when you jump too high)
It took me a while, but I found an interview with the author (Rod Bowkett) in the RetroGamer magazine (pages 56-61):
https://computerarchive.org/files/compu ... ue_062.pdf
Basically, the problem is that after the last eight level, theres no secret Blitzen lab, where you need to set up explosives (time bomb), as it says in the instructions.
Instead, the game returns back to the first level, without any congrats message or anything else.
I can only assume that its a lack of memory, but Rod Bowkett says he is sure he wouldnt leave the game unfinished in such a way.
https://computerarchive.org/files/compu ... ue_062.pdf
Basically, the problem is that after the last eight level, theres no secret Blitzen lab, where you need to set up explosives (time bomb), as it says in the instructions.
Instead, the game returns back to the first level, without any congrats message or anything else.
I can only assume that its a lack of memory, but Rod Bowkett says he is sure he wouldnt leave the game unfinished in such a way.
- Ast A. Moore
- Rick Dangerous
- Posts: 2640
- Joined: Mon Nov 13, 2017 3:16 pm
Re: Exolon Crashing Bug Fix (when you jump too high)
Right, but the article also says:
Still, an interesting case. It’s possible that he accidentally sent in the wrong version (unfinished).Since speaking to Rod, a disassembly of his code has been posted on the World of Spectrum forums and it confirms that there is indeed no proper ending to the game.
EDIT: Just took a very superficial look at the game, and boy is it packed! I don’t think there’s room for adding extra game logic.
Every man should plant a tree, build a house, and write a ZX Spectrum game.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
Re: Exolon Crashing Bug Fix (when you jump too high)
So... Where is the RIGHT version !!Still, an interesting case. It’s possible that he accidentally sent in the wrong version (unfinished).
I don't have anything cool to put here, so i'll just be off now to see a priest with yeast stuck between his teeth and his friend called Keith who's a hairpiece thief...
Re: Exolon Crashing Bug Fix (when you jump too high)
That's the good question, but I'm not sure even Rod knows the answer, now.
This is one of the best Spectrum games ever in every sense and honestly, I would be more happy to find the complete version, than the discovery of Mire Mare.
I'm not sure if theres an disassembled version, which would help to find out, if theres a trace of the Blitzen lab or if there was no space at all...