Games with bugs: Nyancle Racing (MSX2)

Pagina 1/3
| 2 | 3

Door MP83

Master (236)

afbeelding van MP83

03-10-2022, 19:57

Hello again,

Posting about this here, in case anyone can help and fix the game. In the MSX2 game Nyancle Racing, whenever you beat a level, you switch to another racer/car. This is nice and all, but there's a couple of times when choosing the yellow racer causes the game to be unbeatable (green, red, and blue racers are all fine, as is Nyancle himself).

This bug doesn't happen immediately when you choose the yellow driver, and it only happens on certain courses (courses 2 and 4, at least). But when it happens, it happens every, single, time. You play a level normally as the yellow racer, but once you finish that level and you're supposed to switch back to the Nyancle, this happens:

Nyancle, who you're supposed to reach to get to the next level, is suddenly stuck on the top-left corner.

I don't know why this bug only happens with the yellow racer specifically, but I've noticed that he magically does have a much better side movement speed in some levels, even if you don't have any Steering Wheel items. This might be somehow related to this bug.

Aangemeld of registreer om reacties te plaatsen

Van sdsnatcher73

Enlighted (4298)

afbeelding van sdsnatcher73

03-10-2022, 20:15

Just to make all information complete. How are you playing the game? Emulator or hardware? Which machine are you using (valid in both cases)? In case of hardware, are you playing from a real disk or using SofaRun or other disk emulation? In case of real disk, is it an original copy or a backup?

Why so many questions, some issues happen only under specific conditions. On different hardware the game may run without issue. Also if there was a copy protection which was removed, the result may still cause issues (a second level protection).

Van MP83

Master (236)

afbeelding van MP83

03-10-2022, 20:25

Another bug is a visual one: the item counters are not showing the numbers correctly beyond 09.

This is what the counters look like when you have 10 of each item, for instance:

The max value for each item is increased by 5 after every Course, the max being 5 on Course 1, which means that you can't encounter this visual bug until you reach Course 2.

Van MP83

Master (236)

afbeelding van MP83

03-10-2022, 20:31

I've been using openMSX for now (the latest version 18.0), emulating different dumps of the game (3 Japanese ones and 1 English fan-translation), using different MSX2 and MSX2+ models. I'm fairly confident that this is a bug with the game itself, but it could still be a bad dump. Haven't done further testing, yet.

Yet another bug or feature is that if you collect any more Candy after collecting 99, the counter will reset back to 0. Very annoying. Wink

Van sdsnatcher73

Enlighted (4298)

afbeelding van sdsnatcher73

03-10-2022, 20:50

The counters surely seem like a bug.

Van MP83

Master (236)

afbeelding van MP83

11-10-2022, 23:43

Yellow driver/car causes issues for Course 5, as well.

Van MP83

Master (236)

afbeelding van MP83

10-03-2023, 15:27

Update: The bug with choosing the yellow driver happens with most courses (courses 2-5), but not the first one. I still don't know why this bug is happening, but I've pinpointed the issue being that the memory addresses 0xD720, 0xD721, 0xD730, and 0xD731 are all set to 0 for some reason, which makes the other racer appear on the top-left corner:

These are the correct values:
POKE 0xD720 56
POKE 0xD721 120
POKE 0xD730 56
POKE 0xD731 120

Is anyone able to fix the game with this information? This bug has remained in the game for about 35 years now. Cheers! :)

Van NYYRIKKI

Enlighted (6092)

afbeelding van NYYRIKKI

11-03-2023, 16:12

Working on it...

Edit: Hmm... Ok, now I see where it does wrong, but how the heck I put a patch in there without breaking everything! Grr...

Van NYYRIKKI

Enlighted (6092)

afbeelding van NYYRIKKI

11-03-2023, 16:21

One more byte... I need to optimize 1 more byte from somewhere...

Van NYYRIKKI

Enlighted (6092)

afbeelding van NYYRIKKI

11-03-2023, 17:08

Oh crap... Sometimes you think the solution is around the corner while in reality you are in wrong city... This is a bigger design issue... If I fix the routine to work on this particular case, it starts to fail on another... Need to dig deeper...

Van Manuel

Ascended (19678)

afbeelding van Manuel

11-03-2023, 17:34

having fun, NYYRIKKI? Smile

Pagina 1/3
| 2 | 3