WHDLoad games running too fast under emulation

[endre1952]

When I had my Amiga 1200 with a Blizzard IV 68030 board and fast mem, most games ran at proper speed when running WHDLoad patched version. But these days I use emulation (unfortuantely...) When using Android (Retroarch P-UAE core), UAE4Arm, Uae4all2 or other portable-platform Amiga emulators, some games run too fast, unless I set the emulator to use a 7 MHZ 68000 CPU. Can you explain why these games behave differently under emulation VS real expanded hardware:

[jotd]

That's because of several factors

1) Not all games run too fast. Only the ones that either use non regulated loops, or vbl sync but assuming that a full frame has already passed when it's not the case (thus doubling the speed). There are a lot of them, and I'm trying to fix them when I encounter those issues (I fixed New Zealand Story, but also Earl Weaver Baseball, Magic Pockets, Led Storm, Populous 2, One on One, Advantage Tennis...)

2) on real machine with accelerators, code running in chipmem runs slower than on a mere A1200/020 (I don't remember the reason but that's a fact: my A1260 crawls when code is in chipmem) so the issue don't appear unless the code runs in fastmem. On an emulator, those chipmem slowdowns aren't emulated and it runs fast.

So if you encounter a game which is running too fast, open a mantis issue: https://mantis.whdload.de

[Anubis]

There is an option on PC emulators to change settings from withing emulation at start and exit of WHDLoad, but as far as I know, this was not propagate on P-UAE and rest of emulators. 2 lines changing speed to A500 speed and cache will do the trick and make all game run correctly on windows emulation.

I raised a question couple of times with UAR4ARM, but as far as I know, it is not implemented yet. (if someone knows different, I would gladly check it tonight )

[jotd]

you can use a startup script to disable JIT. I always do that because JIT is too fast and has too big caches. Most games just can't cope. And I also set to "standard A1200".

But running the emulation super-slow isn't really the best solution. Games needing power will be slow so you'll need one config per game: exactly what we're trying to avoid.

I try to fix games so they work with "fastest / no JIT" setting.

[endre1952]

Thanks for the info. Bubble Bobble comes to mind at the moment, but I think the speed issue is fixed in the latest WHDLoad patch, I just haven't tested it yet.

I prefer the P-UAE Retroarch core in Android, which runs delightfully on my Razer Phone 2, even properly handling 50hz smooth scrolling.