Gotek OSD not working on Atari Hi-Res (wrong refresh rate)

HxC Floppy Emulator on Atari ST support
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julianw
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Joined: Sun Mar 08, 2020 12:58 am

Gotek OSD not working on Atari Hi-Res (wrong refresh rate)

Post by julianw »

Hi there, I've wired my gotek to my Atari, hoping to use the OSD function in my Atari in Hi-res mode.
Hi-res monochrome is the only mode I can use with Notator.
I'm really happy with the Gotek performance, except the OSD function is not working properly.
Unfortunately the text is garbled, I think it is becuase the firmware is set to 31Khz, and the display needs 35.8Khz

I downloaded the custom firmware with both VSYNC & HSYNC and attached the Gotek to the appropriate place in the circuit.
I experimented with different 'Screen / resolution types'
[40x24 - 31khz] was the closest but the text is still garbled

With the Atari connected using Hi-Res>VGA cable the monitor reports:
Resolution = 640x400
Vertical refresh rate (VSYNC) = 72Hz
Horizontal refresh rate (HSYNC) = 35.8kHz

As you can see the text is displayed but is garbled.

This 35.8Khz horizontal refresh rate reported by the monitor is corroborated by information in the pages below:
https://info-coach.fr/atari/documents/myFAQ.php (VSYNC 71Hz HSYNC 35.8 KHz)
https://www.exxoshost.co.uk/forum/viewt ... 5&start=40 (VSYNC 71.2Hz HSYNC 35.8 KHz)


If possible could we get a custom firmware update with the option set to 35.8khz, would be most appreciated.
I spent a lot of time getting this far, and it would be nice for it to be functioning fully :)

Thanks
The pictures below explain the wiring for anyone wishing to undertake this in Hi-Res mono mode.

Image
Image
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Jeff
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Re: Gotek OSD not working on Atari Hi-Res (wrong refresh rate)

Post by Jeff »

Can you make a small video to show me the current OSD state at 35 khz ?

EDIT : I think that the HSync delay is just too long, i will short it.

Jeff
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Re: Gotek OSD not working on Atari Hi-Res (wrong refresh rate)

Post by Jeff »

Custom firmware updated :

Try the 31Khz settings. Think to clear the internal settings after the firmware update (press the right button at power up).

julianw
Posts: 3
Joined: Sun Mar 08, 2020 12:58 am

Re: Gotek OSD not working on Atari Hi-Res (wrong refresh rate)

Post by julianw »

Hi Jeff,

I just got around to trying the updated firmware and it works fine now, I did need to clear the internal setting as you mentioned.
The text is stable and legible now.

Just for your information - When the Gotek starts accessing (exactly 4seconds after selecting the disk image - when the text changes to display Track i.e T:007/255) there suddenly begins a lot of noise in the text, it seems like interference/noise but the text is stable and readable when selecting disk images and that is all I need.

Thanks for the firmware fix, most appreciated :)

Jeff
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Re: Gotek OSD not working on Atari Hi-Res (wrong refresh rate)

Post by Jeff »

Good !

I am interested by a picture to see it working in Hi-Res mode. :)

julianw
Posts: 3
Joined: Sun Mar 08, 2020 12:58 am

Re: Gotek OSD not working on Atari Hi-Res (wrong refresh rate)

Post by julianw »

Hi Jeff and everyone interested hope you are all keeping well,

Sorry for the delay posting these, here are some pictures in hi-res mode, I think the text maybe brighter if I reduced the resistor value, however it is readable and I'm Happy :)

Image
Image

Jeff
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Re: Gotek OSD not working on Atari Hi-Res (wrong refresh rate)

Post by Jeff »

Thanks !
(you know that you can use the normal mode now you have the osd ? Use the normal cfg file, or just remove completely the config file !)

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