Topic: FBN Bugs Reports

[dink]

the_maq, thanks for letting us know - I will take a look into it when "Operation: Rewrite-Spectrum" is complete.

best regards,
- dink

[Neville]

Neville, it's strange - some games seems to access the kempston completely wrong.
My theory is that I think the authors never had a kempston interface to test with, but they added code for it.  Because I can't get [the games I tried] working on any emulator w/kempston.  I didn't try them all though.  If you do find one that works in Fuse or Speccy (or something else), but not fbneo - please let me know, then I can possibly track down the issue.

best regards,
- dink

I see. I've noticed a few games where Kempston doesn't seem to work right, but from a layman point of view it's hard to tell wether it is a FBN issue or just bad programming from the original developers.

One issue I've noticed, though, it's that in some games Kempston control causes the game to pause intermitently. I just saw it on "Yie Ar Kung Fu", and it runs well with emulated Kempston on Spectaculator.

Thanks for the answer.

[dink]

I see. I've noticed a few games where Kempston doesn't seem to work right, but from a layman point of view it's hard to tell wether it is a FBN issue or just bad programming from the original developers.

One issue I've noticed, though, it's that in some games Kempston control causes the game to pause intermitently. I just saw it on "Yie Ar Kung Fu", and it runs well with emulated Kempston on Spectaculator.

Thanks for the answer.

Can you try to find more games where the kempston works fine in another emulator but not fbneo?  I'd like to fix this problem, but need a little more to go on

best regards,
- dink

[Neville]

I'll try.

EDIT: "Barbarian II - The Dungeon of Drax (128K)".

"Chicago's 30" --> Doesn't recognise joystick left, but Kempston option doesn't work in Klive, at all.

"Desperado (Topo)" --> Joystick unresponsive, same result in Klive.

"Freddy Hardest" --> Some Kempston combinations pause the game. Works fine in Klive.

"Game Over" --> Fire returns you to main menu. Doesn't have a Kempston specific option, but works fine with Kempston on Klive.

"Lotus" and "Test Drive 2" --> Joystick keeps leaning on the right. Couldn't get Kempston to work under Klive, in either case.

Hope you will have enough test subjects for now. If you need more, just say it.

[dink]

Neville thanks, but please use reply instead of edit - I didn't even notice for a couple days.

best regards,
- dink

[pintcat]

On the 2DS/3DS, FBNeo is unable to open a few of the NeoGeo ROMs. So far I found Metal Slug 2 and King of Fighters 98 not working. Most of the time the program simply quits back to the home menu. Sometimes it even crashes the whole system. It might be size dependend, because smaller ROMs like Metal Slug 1 or Viewpoint work fine. All these ROMs work with FBAlpha on the very same system. Tested on a new 2DS with the latest stable version 1.9.0.

[barbudreadmon]

On the 2DS/3DS, FBNeo is unable to open a few of the NeoGeo ROMs. So far I found Metal Slug 2 and King of Fighters 98 not working. Most of the time the program simply quits back to the home menu. Sometimes it even crashes the whole system. It might be size dependend, because smaller ROMs like Metal Slug 1 or Viewpoint work fine. All these ROMs work with FBAlpha on the very same system. Tested on a new 2DS with the latest stable version 1.9.0.

Yes, this is definitely a memory constraint issue, there would be no reason for smaller roms to be working otherwise. Sorry but there is nothing we can do about this, FBNeo will keep getting bigger and using more memory every time we add support for new games.

[Neville]

Neville thanks, but please use reply instead of edit - I didn't even notice for a couple days.

best regards,
- dink

Uh, sorry.

[pintcat]

Yes, this is definitely a memory constraint issue, there would be no reason for smaller roms to be working otherwise. Sorry but there is nothing we can do about this, FBNeo will keep getting bigger and using more memory every time we add support for new games.

Pity. But wouldn't it be possible to split it into smaller cores which then support only certain systems? Like a pure CPS core, a pure NeoGeo core etc.

[barbudreadmon]

Pity. But wouldn't it be possible to split it into smaller cores which then support only certain systems? Like a pure CPS core, a pure NeoGeo core etc.

Maybe, if you want to create X repos for split cores dedicated to devices with no memory and maintain them, feel free. Personally i won't provide support for this.

[dink]

It is a good idea for some systems, but definitely not something we can do / maintain (with our limited resources)  Perhaps the maintainer of the *DS version can do this.
Arcadez maintainer of FBL uses this technique for his original Xbox port - most Xbox's only have 64megabyte of ram.

best regards,
- dink

[Neville]

A couple more Spectrum bugs:

Casanova --> Kempston acts as if the right direction was continuosly pressed. Keyboard works fine.

Silent Shadow --> Can't get past the main menu, the option to start the game (0) seems to have no effect.

Both bugs can be reproduced with Klive, but Casanova works fine with Spectaculator.

[dink]

Neville,
I found a video where they dissect a Kempston interface and explain how it works ( https://www.youtube.com/watch?v=4e1MlxPVyD4 ), this lead me to emulate the hw a bit better.  Now Casanova & Hostages work fine.  Desperado still doesn't, but - I think that game is just bugged anyways.

Thanks for your feedback

p.s. Silent Shadow is a weird game, it will only work if you define keys and use keyboard (teclado) to play it.  also, press '8' to start, it kinda looks like '0' though.  This game also has problems with joy in other emu's.  weird..

(p.s.2, new spectrum code won't be on github until tomorrow or later today - got some big changes cooking)

best regards,
- dink

[Neville]

Awesome news, dink. On one hand I'm sorry I keep telling you guys to add games and solve bugs. On the other, I know this will eventually lead to better emulation.

One thing, though: Can't help but notice how many of the troublesome games are Spanish. Makes me wonder what went on in my country on those days... tight schedules and too much cofee, I guess.

EDIT: And as usual, I forgot to thank the devs for the giant steps Spectrum emulation has taken since the last official release. TAP support, an expanded roster and now better Kempston emulation are terrific achievements, and they make very excited about future releases.