MiSTer FPGA Forum

I lately got my miSTer and am really happy with the wonderful piece of hardware! Not so familiar yet but learning constantly…

I have a question to other users or anybody having an idea about this with 2,4 GHz wireless keyboard/mouse combination:

When playing Metal Slug 3 with the keyboard the game freezes after some minutes or even sometimes right after starting a game. Only the display of the game freezes, the sound continues, OSD still works as normal. Happens all every time. At first I thought there is something with the RAM module but then I plugged in my XBox 360 controller and used it instead of the keyboard and it did not freeze anymore. I have to try this more often to verify this but it seems to work with the controller.

Does anybody have an idea what could cause this weired behavior?

I just can confirm that when playing with a joystick/joypad no freezes occur.

There seems to be a problem when using the keyboard for controlling games and pressing keys very often. At least with my 2.4 GHz wireless keyboard.

Can anybody say something about this?

It is not that cool to play with keyboards that you will freeze

What keyboard is it?
A link would not hurt.

Is it a cheap chinese keyboard or something like a logitech K400?
For the cheap chinese i would not be surprised if it does not work very well when used much as in holding down keys for long, maybe the cpu in it simply gets overwhelmed and stops working for a while to catch up.

Have you tried another keyboard?
Maybe another cordless keyboard but also a regular usb one as well?

Do you use a cordless mouse/wifi/gamepad/joystick?
Maybe it is some interference going on
If so try to plug them in as far away as possible from the keyboard dongle or maybe even use a usb extension cord for the keyboard dongle so it gets away from them.
Could be worth trying a usb extension cord just to get the dongle away from the mister too if that is causing some interference on the mister.

I bought this keyboard/mouse combination for MiSTer:

https://www.amazon.de/gp/product/B0861X82P4/

The keyboard is just great, good quality. Much like my iMac keyboard.

I do not plugged in anything else at the moment. Just power, HDMI and the dongle for the keyboard.

But the biggest question: how could high speed key presses make the game freeze? And why is sound still playing and the OSD can still be opened and used?

Looks like it is the same dongle for both the mouse and keyboard.
So do you use the mouse at all?
If not is it still connected but not in use?
Where is the mouse? as in is it close or far away?
Maybe it tries to connect now and then and causes the lag/freeze? Then having it closer could solve it.

Does it gets pushed out of the way and maybe a button is pressed by something that does the lag/freeze?
Had this happening to me one time bought a new mouse but was not sure i would like it so put the old one out of the way, about a year later i started having strange problems and it took months of dicking around until i decided too unplug everything and put in one thing at a time.
And did notice one more cable hmm where does this go and started to drag it out but nope so had to move half the damn room to get to it and presto my old mouse laying on it´s side jammed between the wall and something else i can´t remember and apparently fitted just so perfect that the right mouse button was depressed to just about too click.

So sometimes that damn button would be pressed, other times not, other times going on/off as soon as a butterfly farted across town.

Maybe try to unplug the battery in the mouse and try and see what happens?

And now after writing all this i read the ""But the biggest question: how could high speed key presses make the game freeze?"" again.
Which is a damn good question and i misunderstood/read too fast and only thought about the keyboard as in it was the keyboard that stopped working for a while.

So the above is probably not off much use besides the mouse could maybe cause something.
And look at the mouse so it´s not pressing any button, moving it closer to the dongle, unplug battery is pretty easy and fast too do.
Other then that i would try another keyboard and see if the same thing happens?


Wait i just thought of one more thing!
What powersupply do you use?
Is it the one that comes with the DE-10 nano?
If so then there is a chance that it does not deliver enough power, usually this does not happen with only one keyboard plugged in.
But i would probably try another PSU and preferably with a 5V 3A or higher A, the de-10 one is 2A.

If the OSD still works and game sound continues to play, then the system as a whole isn't locked up. At the very least, the HPS is still running, the scaler is still generating HDMI output and accepting OSD input, and the core's sound subsystem is still running. I think this suggests one of:

• The scaler stopped processing core video input
• The core's CPU is stalled
• Something in the game itself causes it to lock up

A few questions to try to narrow this down:

Are any additional sound effects or music tracks played while the display is frozen, or does it only continue to play something that was started before the freeze?

Does the freeze occur with any other game, or only Metal Slug 3?

Is the freeze possibly associated with any "impossible" input combinations, such as pressing left+right or up+down simultaneously?

ExCyber wrote: ↑Tue Nov 23, 2021 3:38 pm Is the freeze possibly associated with any "impossible" input combinations, such as pressing left+right or up+down simultaneously?

A lot of NES games show undefined behaviour when doing this, most of them are being abused in TAS videos to speed boost

I‘m using a better PSU, provided by Ricardo.

The mouse can not be turned off, only the battery removed. But on the other side it’s in sleep mode until I wake it up by pressing a mouse button. So I don‘t think the mouse is causing this.

One thing that is possible is that if Neo Geo games eventually lock up when pressing „impossible“ key combinations like up+down as the up and down arrow are really close to each other so it’s possible that I press both at the same time. But do you really think this could be an issue?

As I already wrote, only the picture is frozen, the music is still playing. OSD is also working.

I didn’t have the time yet to test any other game.

But as I said, when using a Joystick/Gamepad no freezes occur.
The only thing I find annoying is that my wireless XBox 360 controller keeps loosing sync after a reset of the miSTer, have to pull the usb cable and put it back in to get sync again.

This seems to be a bug in Metal Slug 3-5. You can push left+right all you want, but doing that and shooting or throwing a grenade locks up the game.

There might be a conversation to have about disallowing these input combinations by default since they tend to cause strange behavior.

Many many thanks for the info! You made my day!

Does anyone know if there is a way to disable those input combinations?