Atari Lynx Core

FoxbatStargazer
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Re: Atari Lynx Core

Unread post by FoxbatStargazer »

You need to enable "240p mode" in the menu to make the image larger. Though I'm curious about the erratic part and if it still stays erratic after enabling.
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Re: Atari Lynx Core

Unread post by flynnsbit »

FoxbatStargazer wrote: Fri Mar 19, 2021 4:47 pm I'm getting some weird analog output on my VGA CRT via the Analog I/O board (not direct_video). I've got the forced scandoubler on, and I use the 240p mode setting in the core menu. The entire screen appears wavy, like every other line is shifted slightly left or right, although it is stable like this it appears rather fuzzy. This even applies to the OSD. It goes away if I use the HQ2X scandoubler mode and only that one, its fully present with scanlines or off. This might be because the total pixel clock is a bit low or something, only 408p tall? I know I can get around it with vga_scaler on a vga monitor but thought I would bring it up.
Yeah I am seeing the same thing on my VGA MoniVision Presentation display at 31Hz. It's almost like every other line horizontally is shifting quickly left and right causing a "fuzzy" look. I noticed if you turn on the scandoubler and turn up the scanlines to either 50% or 75% it fixes it or "hides it"
metalfacemark
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Re: Atari Lynx Core

Unread post by metalfacemark »

Jegriva wrote: Sat Mar 20, 2021 12:23 pm
metalfacemark wrote: Fri Mar 19, 2021 4:43 pm great job on the core - the 240p mode works briliantly on my CRT TV.
Are you using Vga_scaler=1?

Via natural analog I get a minuscule erratic image on my CRT. (Consumer television, not cathodic pc monitor).
No, vga-scaler 0 - its on my CRT TV. It was very small till i changed it to 240p option.
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Re: Atari Lynx Core

Unread post by FPGAzumSpass »

LamerDeluxe wrote: Sat Mar 20, 2021 11:11 am When testing a color trick demo, which changes the palette every scan line, racing the beam with horizontal blanking interrupts, you can see that the timing doesn't match that of a real Lynx, possibly because of the non-standard frame rates of the Lynx.

The turbo option often doesn't have an effect, but when it does it is often way too fast. It would be great if it could be set in steps. I'd personally love to see a 24Mhz option that speeds up everything, including audio and timers, so it could be used to develop something for real Lynxes with 16 Mhz to 24 Mhz overclocking (I have an overclocked Lynx). 24 Mhz was the original clock speed of the Lynx, lowered to increase battery life.

I've made some small Lynx demos that use flicker transparency effects. The display of an original Lynx is very slow and blends about three subsequent frames together. The popular physically released home-brew game Zaku uses this effect as well. I'd love to see an option in the core to blend at least two frames, if possible. This could also make the games look more smooth.
Please send me the HBlank IRQ demo so i can debug the core with it.

For 24Mhz mode: i plan to add Turbo/Fastforward speed select. Currently it's 400%, but i will also do 50%, 100% and 200%.

Interframe Blending could be added. If you have a demo to test, please also send me.



For the scandoubler problems: i cannot reproduce this with HDMI output here and i don't have any analog out board or CRT here.
Not sure what i can do...
FoxbatStargazer
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Re: Atari Lynx Core

Unread post by FoxbatStargazer »

Mister is reporting 32.02 khz for analog output when using the forced scandoubler (whether hq2x or not). Meanwhile gameboy advance reports 31.55 khz. Maybe something is related there? Didn't you do some work on the gameboy/advance cores, maybe you can use similar settings?
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LamerDeluxe
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Re: Atari Lynx Core

Unread post by LamerDeluxe »

FPGAzumSpass wrote: Sat Mar 20, 2021 6:10 pm Please send me the HBlank IRQ demo so i can debug the core with it.
I have a couple of loose demos that would be handy for testing. I'll have to convert them to .lnx files. I'll look into it tomorrow.
For 24Mhz mode: i plan to add Turbo/Fastforward speed select. Currently it's 400%, but i will also do 50%, 100% and 200%.
That would be great. For instance for Warbirds and Toki.
Interframe Blending could be added. If you have a demo to test, please also send me.
My small Lynx demos can be downloaded from my Demozoo page here:
https://demozoo.org/sceners/67377/
All three of them use transparency flicker effects. I also have a couple of small demos that use three frame RGB blending.
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ccovell
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Re: Atari Lynx Core

Unread post by ccovell »

Thanks for the core!!! It works quite well -- using a CRT monitor in 15khz mode most of the time. Sometimes I use MiSTer in 31khz VGA.

A couple bugs or problems:

In both 15Khz and 31Khz mode, when using the '240p mode' option, the top row of Lynx pixels get stretched to 3 pixels high, and the bottom row of pixels gets "stretched" to only 1 pixel high. Have you done this intentionally?

Also, in 15Khz mode, when I turn off 240p mode and rotate the screen, the menu itself disappears.
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Re: Atari Lynx Core

Unread post by FPGAzumSpass »

i wasn't aware that this(3/1 pixel) happens in 240p mode, but i can reproduce it and will fix it.

That the menu disappears in non240p mode might happen.
Non240p mode gives out quarter resolution with LARGE blanking area at same pixel clock.
If someone wants to work on all that I'm fine with it, but i cannot test all these without analog out components or CRT, so I'm not the right one to do it.


@LamerDeluxe: thanks, found the flickering demos and could reproduce it.
Will add a 2 or 3 frame flickerblend option (off, 2 frames, 3 frames)
Milspex
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Re: Atari Lynx Core

Unread post by Milspex »

Lynx core doesnt recognize the games/lynx on usb0 drive, correct? It just defaults to atarilynx dir on fat

Nevermind it should be games/AtariLynx
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Re: Atari Lynx Core

Unread post by MiSTerEggman »

jca wrote: Fri Mar 19, 2021 3:40 pm
MiSTerEggman wrote: Fri Mar 19, 2021 3:11 pm im a moron lol... thanks

just surprised my script didn't do its thing that is supposed to cover that
No, just too exited to try a new core like many of us are. Not being near my MISTer I had time to RTFM.
Are you the author of the BIOS getter script? In the affirmative shame on you, you may have killed some baby seals.
by 'my' script, I meant the script on my MiSTer. my mistake.

I'm not the author
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Re: Atari Lynx Core

Unread post by Waifu4Life »

Shouldn't this core have it's own sub-forum now?
Thad
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Re: Atari Lynx Core

Unread post by Thad »

Is there any way to get it to automatically launch a specific ROM when you open it? I have the same rolling picture issue with this core that I do with several others; opening a game fixes it, so I'd like to have it automatically load a game at start. (The boot.rom doesn't do it.)
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pgimeno
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Re: Atari Lynx Core

Unread post by pgimeno »

In the GameBoy core I use boot1.rom for the BIOS and boot2.rom for the ROM to open, have you tried that?
Thad
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Re: Atari Lynx Core

Unread post by Thad »

pgimeno wrote: Sat Apr 17, 2021 8:03 pm In the GameBoy core I use boot1.rom for the BIOS and boot2.rom for the ROM to open, have you tried that?
Good news/bad news on that. The good news is, boot1.rom/boot2.rom works; the ROM loads at startup time. The bad news is, whatever was happening before that fixed my picture when a ROM got loaded, it isn't happening anymore; I assume a core update somewhere along the line broke it. Now no matter what ROM I load, I end up with a picture that's rolling, wavy, or misaligned. I've tried adjusting settings, includingV-sync and H-sync and 240p mode; no luck.

ETA: It's not limited to the Lynx core; I'm having problems with the picture across multiple cores. I'll see if I can figure out what happened.

ETA2: Fortunately, the solution turned out to be dead simple; I must have bumped the Sync on Green switch and turned it off. After I switched it back on, everything's working fine; the Lynx core loads a ROM (Electrocop) on boot and that fixes the rolling picture issue. Thanks for your help.
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