Grog's Revenge for the MSX is broken. Impossible to fix?

Master (232)

24-02-2019, 20:57

The MSX version -- all of the releases -- is unbeatable because of an issue: There's a spot in the final level (Level F) where the road corner doesn't take you to the spot where it should, but instead takes you back to the very beginning of the level, therefore making it impossible to make any more progress/beat the game.

Can anyone with the skills and knowledge fix this game for us? Thanks!

Codes to reach Level F faster (you can only skip one level at a time):

Level A: When inside the first cave, type 22 (warps you to Level B)
Level B: When inside the first cave, type 23 (warps you to Level C)
Level C: When inside the first cave, type 44 (warps you to Level D)
Level D: Move right, turn around the corner, move right, turn around the corner, enter the cave, enter it again and type 45 when inside (warps you to Level E)
Level E: Move right, turn around the corner, enter the cave, enter it again and type 62 when inside (warps you to Level F)

By NYYRIKKI

Enlighted (6067)

25-02-2019, 01:18

Warp directly to level F in openMSX:
- Go to to 1 player / 2 player selection screen
- open openmsx console (F10)
- type: poke 0xE08C 5

By tsMKG

Resident (48)

25-02-2019, 22:31

I think that should be a patch, isn't there any program to patch MSX ROM or DISK files?

By Manuel

Ascended (19462)

25-02-2019, 23:42

It's not a patch. It's a poke. He's writing the level variable memory address... or something similar.

By gdx

Enlighted (6210)

26-02-2019, 00:48

@MP83, Can you try theses versions and see if all have the same problem or not?

https://mon-partage.fr/f/ibgdZ2VV/

By tsMKG

Resident (48)

26-02-2019, 02:08

Manuel wrote:

It's not a patch. It's a poke. He's writing the level variable memory address... or something similar.

Oh, thanks, I misread what he said
I tought he said the actual fix.

By MP83

Master (232)

26-02-2019, 02:55

gdx wrote:

@MP83, Can you try theses versions and see if all have the same problem or not?

Yes, they all have the same problem. The Prosoft (bootleg) release was news to me.

By araubi

Champion (434)

27-02-2019, 07:50

A fixed version wil appear very soon here:

http://msxfx.blogspot.com/

Cheers.

By MP83

Master (232)

27-02-2019, 10:19

That's good to hear. By the way, the game also randomly freezes when exiting a cave, but that's probably too hard to fix. I don't know what triggers it.

By araubi

Champion (434)

27-02-2019, 11:35

Really? It never happens to me, with OpenMSX? Which configuration?

By MP83

Master (232)

27-02-2019, 12:18

When emulating National CF-3300 in openMSX, at least. It happens very rarely, but it does happen sometimes.

// If I'd have to throw a wild guess, it may only happen with caves with two exits. Those caves takes you to a different spot, depending on whether you're on the left or right side of the screen when exiting. Maybe test it if the game freezes when you're exactly in the middle of the screen when exiting one of those caves, in case the game tries to take you to two spots at the same time? Again, just a wild guess.