Re: [hatari-devel] "SECAM" STE's

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 05/11/2024 à 21:28, Adam Klobukowski a écrit :

wt., 5 lis 2024 o 20:45 Christian Zietz <czietz@xxxxxxx> napisał(a):

Adam Klobukowski schrieb:

> Main clock generator on mb has following description: 31.922046 MHz

Hm, I wonder whether Atari installed the wrong oscillator or someone
else changed it later.

Other French STEs have a 32.084988 MHz crystal oscillator, as can be
seen on these photos:
https://www.exxosforum.co.uk/forum/viewtopic.php?f=51&t=3625,
https://www.exxosforum.co.uk/forum/viewtopic.php?f=51&t=851 and also in
the STE's schematic.

In other word's: I would not change Hatari based on a (presumed)
odd-one-out STE.

Here are photos of the oscillators of the mobo in question. Looks like factory work.

https://www.dropbox.com/scl/fi/mv6e26ts5z7ruz5iqpj78/IMG_20241105_204629_3.jpg?rlkey=xjbye1od153ze39e12903h6uo&st=6s5v4hx7&dl=0

https://www.dropbox.com/scl/fi/z2blss29to9ag75qaj5w5/IMG_20241105_204820_3.jpg?rlkey=k3xvvtz4szjt6kacvdgzz11se&st=uqywbekz&dl=0

https://www.dropbox.com/scl/fi/drss0xcda3zm4y2m8e0p5/IMG_20241105_204901_8.jpg?rlkey=jayvzw4b26kvn4vdmxtsiyj5f&st=kmunl9b3&dl=0

hi

thanks a lot for the photos and running hwtst004 on the real machine, indeed the photos match the hwtst004's results.

To clarify Hatari behaviour regarding this 32 MHz master clock, Hatari only uses PAL timings at the moment when computing the different sub-clocks (including the 8MHz CPU clock). The file "clocks_timings.c" contains value for PAL and NTSC, but NTSC freqs are never used in Hatari, they're just here as documentation, which will make it easier to use them later in the emulation itself.

On my todo list, I have the idea of adding a kind of "advanced settings" pannels in Hatari, where one could choose low levels parameters such as master clock, pal or ntsc, STF/E MMU's revision (IMP or not) and other HW details that are known to make a difference when running programs (but that a "normal" user should not change :) )

In that case, a support for this rather "strange" 31.922046 MHz clock could be added (as well as some other 32 MHz variations that existed over the years/models)

Nicolas