Atari 800 system freezes after 68 seconds

[EvoluZion3]

Tried with several different games, and BASIC itself. System always freezes after 68 seconds. Started occurring within last 4 weeks approx.

[jfroco]

Hello @EvoluZion3
Version of RetroArch and core? Operative System? Game?
It would be great if you could provide a log file as well.

[EvoluZion3]

Hi @jfroco . Apologies for not providing more detail.

RetroArch: 1.21.0
Atari800 core: 3.1.0 630f234
System: Atari 800 and 800XL
Game: tried a dozen games including Boulderdash, Astro Chase, Pole Position. Also occurs in plain BASIC.
Log file attached.

retroarch__2026_01_26__19_11_58.log

Can confirm that older core from my backup (3.1.0 6a18cb2) works correctly and does not freeze, simply by copying the older core file back over my current config. Can confirm that updating the core via RetroArch causes freezing issue again.

[jfroco]

Hello @EvoluZion3

Thank you. I was able to reproduce the error on Windows and Linux.

Workaround: Use NTSC.

Quick Menu -> Core Options -> Video -> Video Standard = NTSC

Please give me a couple of days to fix the issue and publish a new release.

You are using Windows, right? I can send you the corrected version once I have it compiled.

[EvoluZion3]

No problem @jfroco thanks for investigating. Happy to wait for a new release and to test it for you if you wish.
Yes, Windows 11.

[jfroco]

Hello @EvoluZion3

I corrected the buffer frame sizes for audio; they are calculated for both PAL and NTSC based on the current upstream emulator version code.

6a18cb2:

• PAL: 885
• NTSC: 742

630f234:

• PAL: 883
• NTSC: 736

Atari800 values for 44100Hz:

• PAL: 885
• NTSC: 736

Now both PAL and NTSC should sound correct.

Would you mind testing it?

Windows: atari800_libretro.zip
Linux: atari800_libretro.zip

[EvoluZion3]

Seems to work fine, and sound good too. Thanks @jfroco !

[gitGalu]

The bug also causes the browser tab to freeze after a short time in the Emscripten/wasm build.
Which of the values you listed are the intended (corrected) ones? I’ll verify them in the Emscripten build.

[jfroco]

Hello @gitGalu

The correct values are:

https://github.com/libretro/libretro-atari800/blob/master/libretro/core-mapper.c#L31

int snd_sampler_pal = 885;    // (int)(ceil(44100 / 49.8607597))
int snd_sampler_ntsc = 736;    // (int)(ceil(44100 / 59.9227437))

Please verify them.

I'm sending a pull request today.

[gitGalu]

Please verify them.

I'm sending a pull request today.

This also fixed the issue in the Emscripten build. Thank you.

Btw, I’ll ping you over the weekend with a few thoughts on the microcomputer cores.

[jfroco]

This also fixed the issue in the Emscripten build. Thank you.

Excellent. Thank you!!!

Btw, I’ll ping you over the weekend with a few thoughts on the microcomputer cores.

Yes, of course. I'm more than happy to contribute if I can.