Poor lr-mess performance with Ti99_4a on Pi3B+

jamrom2

@Folly How do I display the framrate? I see it via F11 as around 45% if that's it. Usually it's a rolling number right.

Yes, changing resolutions, turning off overlays, shaders.. etc. has no effect.

Folly

Ok,
Probably you are out of luck and you need to get a RPI4.
I would buy a 8GB version because it can run on 1,8Ghz in default in the new bullseye distribution.

Folly

@jamrom2

Don't you have an old x86 or x86_64 computer lying around ?
I would try it on that.

jamrom2

@Folly No, definitely don't. Lol.

I was wondering if it would be worth asking someone on the Librettro team to have a look at this...or even from MAME. It's odd to me that it's only the Ti99_4a that gets beat-up like this. All the other computers from this era seem to work fine.

I suppose nothing will come out of it, but it's worth a try to ask.

Folly

@jamrom2

It has to be addressed in mame if possible.
After that it will automatically go into the libretro core.

You should make an account here and discuss the problem :
https://forums.bannister.org/ubbthreads.php?ubb=postlist&Board=1

It's troublesome to get your username activated.
You probably need to email to get it activated, just like me.
Then you can search the forum.

I have an account too but I can't post anything so far.

Edit:
I did a search for you but could not find anything useful.

Folly

@jamrom2

Have you tried the slider functions ?
Underclocking or overclocking the cpu ?

Perhaps not ideal but have you ever tried running your RPI3 from CVBS instead of HDMI.
CVBS could improve speed also.

jamrom2

@Folly what is cvbs?

I will try the sliders... I used them on one of the handheld games which seemed to help, but it doesn't save.

I didn't want to have to change the basic build too much to fit one system. I'd rather keep it simple if possible. End result is most likely I buy a Pi4.

It's just bugging me because I know how old the Ti99 is as compared to the Apple IIe and Tandy. So you would expect the same results, but I know that's not always the case with emulation.

Folly

@jamrom2

For every system in mame there is a driver.
Some of them are better than others, thats just how it is.

CVBS is the composite video output.
With the early raspberry pi 1 it was the yellow connector :
https://cdn.instructables.com/ORIG/FBD/EEDO/HZCJ4PQM/FBDEEDOHZCJ4PQM.jpg?width=2100

Now it's in the jack plug, so you need to have a cable for that.
And you need a TV that can handle old composite video.
You have to use a cable like this :
https://tinkersphere.com/1906-thickbox_default/raspberry-pi-a-plus-b-plus-composite-to-rca-adapter.jpg

Old camcorders, for example, used these cables also but some of them have colors swapped. So when using such a cable you have to measure how it's connected.

mitu

[...] CVBS could improve speed also.

Why do you think it will ?

Folly

@mitu

Well I have had some experience with it a couple of years ago with some emulators I don't remember anymore.
When using it it back then it definitely improved the speed.
But honestly I don't know if it will work with mame, so this has to be tested.

mitu

@Folly There's nothing that inherently favours using the analog video jack over the HDMI one. You may had better experience with a lower resolution, but I don't see how using one over the other would improve emulation.

Folly

@mitu

You are probably correct.

Edit:
I was curious and just searched my RPI3 and CVBS cable.
Luckily I was up and running quite fast.

You are correct, I just doesn't help.

jamrom2

@Folly I posted requests on both the MAME forum, and LibRetro.

Like I said... if it can be fixed... good. If not, it is what it is. Just hate for it to be as good as you made it and not be able to be used unless you have a Pi4.

Folly

@jamrom2

The maximum improvement I had was :
frameskip 10 + 50% CPU underclock.

When I have some time I will play a little bit more with my RPI3.

Folly

@jamrom2 said in Poor lr-mess performance with Ti99_4a on Pi3B+:

@Folly I posted requests on both the MAME forum, and LibRetro.

Nice !
We like to be updated about this ;-)

jamrom2

@Folly

I got a one word answer from R.Belmont on the MAME forum... "nope". R.Belmont is one of the MAME team, not really the original designer, but has been with the project since it's very first days. So if he says no, it's not an issue that can be changed. It was worth crossing off the list.

I'm going to look into moving up to a Pi4. I've been working on this build for roughly 8 years, perfecting it and honing it to what it's become and I'm very happy with it. It won't take much to move everything over to the new hardware and build.

Folly

@jamrom2

Nice work !