Atari-Forum

Thanks for fixing the site... Was a little worried it might never return.

It looks like the video address is being updated, but the overscan routines aren't working. That would mean the video address register isn't being updated, so the CPU cannot synchronize itself with the video state-machine. And if my memory serves, the currently fetched video data address lives in th...

The quoted statement makes no qualitative claim about Ijor’s English at all, and indeed there are no grounds on which to do so. I can’t fault it, and haven’t. This is my first comment on it at all. I'm glad that was a misunderstanding. “The table below lists the times at which certain tests are app...

In a conversation where each of us has repeatedly misunderstood the other, I don't know how helpful it is to start picking at language now that there seems to be some clarity Ijor's English is much better than is being suggested above. And Ijor knows what he is talking about since he reimplemented ...

This is really cool

I'm curious, are the ROMs (mem files) taken from the decapping you did?

Or, if they're custom, do you have some tool to generate them rather than typing them in in binary? (in the dark ages before I had an assembler, I used Hex...)

Hi Alien, does it also emulate the 6301? (For example, does the Froggies over the Fence 6301 code I wrote run on it?). Yes. And does 4 bit hardscroll work on it? I'm guessing it does, but could you confirm? Yes. Your demo runs fine :) What about sound (full YM emulation?). Every PSG feature is impl...

I'm curious: does it also emulate the 6301? (For example, does the Froggies over the Fence 6301 code I wrote run on it?). And does 4 bit hardscroll work on it? I'm guessing it does, but could you confirm? What about sound (full YM emulation?). And how does it do wakestates? Yes, I know, I'm thinkin...

Hi Ijor, this sounds quite amazing! :D I'm curious: does it also emulate the 6301? (For example, does the Froggies over the Fence 6301 code I wrote run on it?). And does 4 bit hardscroll work on it? I'm guessing it does, but could you confirm? What about sound (full YM emulation?). And how does it d...

Congratulations on your demo sigge! Very impressive first release. Funny you mention no graphics artists, Ajrarn & I were in a group "the Technocrats" but never released anything for the same reason. Then we joined up with ST Connexion and Krazy Rex & ATM gave us bitmaps to make our code sparkle :D ...

Random crazy thought: if one had a monitor which supported a 30Hz refresh rate... one could perhaps do this switch at some point when the screen in low/midrez ends, delay vsync and get a 16 colour 500 and some line screen. Good for displaying static pictures... 8) The fact one would only turn off ou...

Here are a few quick video captures (50Hz, no sound, direct ST RGB feed). All done on same MB with -38 and re-verified to run OK with -38A. Unfortunately I didn't log the respective wakestates. PYM: Also checked with an IMP shifter on the board used above, but that one doesn't behave nice with a no...

Double plus good!

I'd like to see the effect too. Thanks!

An amusing fact for Troed: If I recall correctly, they actually had adaptive code to vary the timing of the the resolution/frequency switches around, just in case there was an Atari out there that had different timings. They read the video counter to see whether the desired line lengths had been obt...

Don't think there is any way. The Video Pointer at MMU is just a counter. The only other function besides incrementing is that Vsync edge provokes the higher bits to be reloaded from Vbase and the lower bits cleared. So only possible way seems to be to provoke a Vsync edge ... Interesting. We'd nee...

For some reason, when you asked this question, it brought to mind that I always wondered whether there might be a way to change the video fetch address mid-screen. I tried to find a means in software, but never succeeded. That's something you could check when you decap/reverse-engineer the MMU. If t...

Btw, this is one of the problems of using a delay chain. It is variable and not completely reliable. The delay would depend on the board temperature. I wonder if this is one of the reasons of the Shifter weird issues observed depending on the warming (wake substates, as Troed call them). Might be. ...

Hi ijor, I'm curious whether you've had any chance to learn anything new on this topic since your last update.

Thanks Bod/Stax, even though you can't read this.

It makes sense they only got EmuTos working for monochrome mode: the Amiga can't do the type of bitplane interleaving the Atari ST uses, but there's only one bitplane in high-rez. Troed is right. Most games turn off the OS since TOS was notoriously slow. I remember using a "SoftBlitter" which replac...

I may be misremembering, but I also think it didn't always work, whereas the the above code did force the Shifter to reset as I wanted reliably. Perhaps RESET only clears the IR registers at certain points? You are (partially) right! Yes, hardware reset might not perform actually a clean Shifter re...

Ah, not exactly switches, but whole frames at each rez. I missed that. But if you can spend so much time, then it might be better to execute the RESET instruction. That is guaranteed to work. Of course, it is much more invasive as will affect things that you might prefer to avoid. I also had some "...

FWIW, here is the shifter reset code from my article:

reset_shifter:
move.l #$VBL_routine, $70.w
moveq #5,d0
loop:
move.b #1, $ffff8260.w
stop #$2300
clr.b $ffff8260.w
stop #$2300
dbra d0, loop
rts

VBL_routine:
rte

Askja wrote:Hi all,

After some months of work, I just finished my giant picture with all the Atari Demoscene!

Enjoy!!

http://undead-factory.fr/demoscene/index.html

Very nice!

Ok, Ich könnte vielleicht mit dem zweiten Teil helfen... ich könnte zB eine Verbindung herstellen mit den Franzosen, mit denen ich noch Kontakte habe. Welche Produkte populär waren, hat meiner Meinung nach mehr damit zu tun, in welchem Land man in den 90ern lebte. Hannover ist nicht in der Nähe von ...