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ivop

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Posts posted by ivop

  3. Posted · Edited by ivop

    39 minutes ago, MrFish said:

    They call it a bowl haircut here, because if you put a bowl on someone's head and cut around the edge, that's the kind of haircut you'd end up with (if it wasn't obvious).

    Yeah, in Dutch we call it a "bloempotkapsel". A flowerpot haircut.

    • Like 2
    • Haha 2

  5. Posted · Edited by ivop

    26 minutes ago, MrFish said:

    And then XXL can feel some sense of accomplishment for all his hard work too. :D

    Yeah, not many people get a dedicated easter egg in a new hardware device ;) And it's hilarious that a lot of people (including me) thought this was his own portrait :)

    • Like 3

  6. Posted · Edited by ivop
    typo ;)

    22 hours ago, VinsCool said:

    his is my own transcription I started from scratch, hence the missing parts that are currently too complex to figure out by ear :P 

    I assume you can run the original game on an Amiga emulator? Perhaps you can mute certain channels to make it easier to determine the chords, bass, melody, etc...

     

    4 hours ago, emkay said:

    Seems, I really have to put the tune here ...

    https://www.youtube.com/watch?v=yiU5RnDvJ2o&feature=emb_imp_woyt

     

    I like the HiScore tune more :D

     

    Seriously though, it sounds better IMHO.

     

    Edit:

     

    A much better recording of Battle Squadron Amiga OST:

     

     

    The current song in question starts at 11:21.

     

    The first few seconds remind me of The Prodigy.

     

     

    Edit 2:

     

    https://www.youtube.com/watch?v=svJvT6ruolA

     

    The short similarity is at 0:31.

     

    • Like 2

  8. Posted

    11 hours ago, VinsCool said:

    I does... except it's broken since the instruments are read every other frame, so crucial parts are missed.

    I really like how you utilized the pulse widths. Never an ear crinching duty cycle. It seems like you do the opposite of a lot SID composers. They start at 50/50 duty cycle, and then modulate to 20/80 or worse. That's when my misophonia kicks in ;) You seem to modulate in the other direction, i.e. releasing the tension instead of increasing it. I like that :) 

    • Like 1
    • Thanks 1

  9. Posted

    10 minutes ago, rensoup said:

    Mindblowing!! Shame you can't like & thank a post at the same time 😃

    Well, I liked it for you ;)

     

    10 minutes ago, rensoup said:

    Interesting that the 50hz version is missing so much stuff and that it is so much smaller... The other tunes I tried reducing weren't nearly as drastically altered. Possibly because they weren't exploiting its potential ?

    Yes, for sure. They used it mostly for snappier and more realistic drums.  Good to see how Vinscool used it for melodic instruments!

     

    10 minutes ago, rensoup said:

    ...Then I have list of a couple of hundred more tunes for you 😆

    :)

     

    • Haha 2

  11. Posted · Edited by ivop

    1 hour ago, candle said:

    this is direct response for xxl's comments on this matter in polish language - for me this was not an issue and i could do it otherwise, but since he wrote what he wrote, i'll design hardware anti-xxl protection that will actually display that guru meditation screen just to proove the point

    this is now personal, and you are free to walk away

     

    guru meditation it will be

     

    If you can detect xxl's "wrongness" and do something like a guru meditation screen, couldn't you just do the right thing instead? Just asking.

    • Like 3
    • Thanks 1

  13. Posted · Edited by ivop

    10 hours ago, Nezgar said:

    Maybe buy a few from a seller first before committing to a larger batch.

    That's very good advise. In the past, when I started a new project and needed a certain chip, I always ordered two or three of them from different ebay/aliexpress vendors. I also did that because one of them might not arrive. Or if it's defective, you have to wait another 2-4 weeks, etc...   But in the end, I have several ICs in two- or threefold, all working :) But it's good practice at first.

     

    Really sorry to hear that you got ripped for a batch of 40 pieces 😮

  14. Posted

    1 hour ago, 777ismyname said:

    I did play around with several more images last night and was amazed at how well certain ones worked out, especially an image of the Atari 5200 Miner 2049er. Even using the old laptop that produced these (I5-5300u), it was surprising that a few million evaluations didn’t take nearly as long as expected. Will give it a go this afternoon on a much, much more powerful machine.

    The best conversions in this thread didn't need that much iterations. 25M-50M should be enough. And if it doesn't look good at 50M, it won't look much better at 500M. Or 2.5B. But if it does look good, you might resolve some errors in the next 50M-100M evaluations.

     

    It's all about source material, optional preprocessing, and tweaking the rastaconv parameters.

     

    Perhaps we should start a how-to thread or something, a tutorial thead :)

    • Like 3

  15. Posted

    4 minutes ago, Preppie said:

    One just listed 99p startbid u might get lucky :)

     

    https://www.ebay.co.uk/itm/ATARI-800XL-Tested-and-Working/133640613467?hash=item1f1d99ee5b:g:fzwAAOSwDjFgBHTm

     

    That's a Taiwan made one from April 1984, if I understand the stamp correctly. Probably fully socketed except for the delay line, and the power supply is OK. Does not look too yellowed to me. So, do we agree not to bid against the topic starter? :)

    • Like 2

  16. Posted

    9 minutes ago, Gunstar said:

    While looking for receivers on ebay and amazon I saw a lot ot the "world" radio receivers, but none of them had the SSB band (required for this project), There are plenty that do, but they aren't referred to as "world" receivers. did your receiver have the single side band?

    It had long wave, short wave, and AM/FM. But I just read some wikipedia info on the matter, and SSB seems to be a different modulation technique. Not sure if our receiver had that. Perhaps that was why we didn't get it to receive weather images, and not my mediocre soldering skills ;) 

     

    • Like 1

  17. Posted

    I remember this was reprinted in the Dutch "Atari Magazine". It was one of the first DIY projects I tried to build, and I failed misserably 😕 Lets say my soldering skills were not developed yet/

     

    I used a so-called "world" radio receiver. As a family, we used to take that one on holidays, and listen to Dutch radio, to the Tour of France, each day. Even when in France ;)

     

    • Like 2

  18. Posted · Edited by ivop

    26 minutes ago, manterola said:

    Capturing the phase of the color data seems to be the difficult part. The luminance sounds easy. This following idea might complicate the design but what about something simple and cheap like a pic to do the phase detection? Is it fast enough?

    I think you need at least 16x the OSC clock, which would be around 57MHz. But possibly the sampling rate is still to low. You'll probably need around 114MHz (Nyquist). Not sure if there are AVRs/PICs that run that fast (120MHz). Basically, you need enough cycles to detect 16 different phases/delays.

     

    A lot of MCUs I have encountered in the past have a trigger/timer unit. You set the timer to 0. Trigger it by OSC going down (start of color clock), timer starts counting (120MHz ticks), stop it when COLOR goes high. The resulting timer value is related to the phase. I hope it is obvious by now that with 32 ticks in one OSC cycle it might still be difficult to detect all 16 states (black/colorburst, and 15 colors). You have to tweak the delay pot very carefully. An ever higher sampling rate would be better.

     

    Isn't there a simple IC which can feed a clock, and another signal, and determines the phase shift, and present that as a byte on 8 of its pins or something? ;)

     

     

    Edit: Perhaps that's why the Beeb version uses an extra CPLD (which is not needed for the Amiga), to determine the color?

  19. Posted

    6 hours ago, Simius said:

     

    If you want 80-column hardware solution working with a special handler, you just need an existing, genuine Atari XEP80 device. If you want to convert a color image generated by the GTIA to the digital image, you don’t need any Pi Zero nor an adapter for $29, but an ordinary S-Video cable for a few bucks. Your LCD TV will convert the image itself. Why do you think the Pi Zero would do it better? 

    There's no cable involved between the video out circuit and the LCD TV. The whole video circuitry is skipped, and led directly (or through a buffer) to the Pi Zero. I also think the adapter board could be made a lot cheaper. But, this is not a project I plan working on. Just giving my opinion and possible solutions as to how to capture the color data.

     

    The timer stuff should still work, but done differently. Start timer trigger by falling edge of OSC, end timer at rising edge of COL, or something like that.

     

    6 hours ago, Simius said:

    edit:

    That is such expensive DVI to HDMI cable?

    My cable was €10,= incl. shipping. You are right, that's not exactly very expensive. I got my Sophia2 through a group buy. Hopefully I can find the motivation to install it this week. Really looking forward to see your crisp image :)

     

  20. Posted

    11 hours ago, ClausB said:

    Thanks for the link. Yes the 7V timings make more sense. I don't see any mention of the rising edge timing. The schematic shows 15 delay lines, the first of which is color 1 and also the color burst signal. The other colors are delays of that, so they all share the same duty cycle. The first delay line inputs OSC, which is definitely 50%.

     

    Consider this: if duty cycle varied then the average chroma voltage would vary, which would appear as luminance signal, causing a change in brightness with each color change. My first years on the Atari were with a monochrome television and I know there was no luminance change with color change. Furthermore, I could see the chroma signal as a ripple on the monochrome image, and see it vary in phase with color.

    Apparently, it was me who misunderstood it for years :) Thanks for the explanation.

    • Like 1

  24. Posted

    5 hours ago, ClausB said:

    No, Atari colors are phase shifted, with constant 50% duty.

    Sure?

     

    This is from the GTIA datasheet:

     

    GTIA-color1.thumb.jpg.e4283f0158f6750f344523cb0d0132cb.jpg

     

    It starts high, and goes low depending on the the color. Next clock, it starts high again.

     

    GTIA-color2.jpg.79a62af7c697bb681fcbfadbd2bd48a8.jpg

     

    Earlier in the datasheet, it lists the number of nanoseconds it stays high (approximately) for each color.

     

    This looks like PWM with a variable duty cycle to me.

     

    Am I missing something?

     

     

     

    • Like 1
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