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ivop

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Posts posted by ivop

  1. Posted · Edited by ivop

    On one of my machines, I replaced the edge connecter by a pin header. I had a keyboard like yours with true metal wires inside, carefuly removed excessive plastic, and soldered another pin header (of opposite sex) to the flat cable. Now you can detach and attach forever ;)

  2. Posted

    13 hours ago, rensoup said:

    I tried generating some super short sine waves with audacity (200+ bytes) and low pass filtered it and it still sounds crap 😃

    That's not what I meant. If you use super clean, generated snippetes of say 256 bytes, you do not need to filter it. Just ignore the replay rate and play at your own speed with fixed point math to create different musical frequencies. Filtering is only necessary if you have for example a 44.1kHz 1s sample of a bass, and you want to resample that to 800Hz. Some resampling techniques do this sort-of automatigally. SINC resampling IIRC.

     

    I'd say, start simple. Waveform buffer: #$1f (128 times), #$10 (128 times). Volume only, do not set any tonegenerator yet. Now play this buffer round-robin at 800Hz, increase pointer by fixed point math, loop at overflow. Depending the increment of the pointer, you get different sound frequencies. Mixing in the tone generator is for later.

    • Like 1

  3. Posted

    28 minutes ago, emkay said:

    The used method here just hikes a channel and writes the volume only . 

    ITYM hijacks ;) Not that I don't make spelling errors, but hiking is something completely different :)

     

    3 hours ago, ivop said:

    256-bytes is enough for a repeating wave to get a pure tone.

    This was at 15.6kHz. At the proposed low replay rate, you can go as low as 16 bytes per period. Perhaps even less, but it complicates the replay routine because of resetting the index register, or LSB with self-modifying code.

  4. Posted · Edited by ivop

    13 hours ago, Xuel said:

    This is the similar to the phenomenon that causes the dark line between brightness levels 7 and 8 in GTIA mode 9.

    That phenomenon is also partly due to the four resistor DAC they used. 36k, 18k, 9k1, and 4k7 (with 5% tolerance), which does not match exact powers of two. Based on 4k7, that should be 37k6, 18k8, 9k4, and 4k7. This could be fixed with a proper R2R ladder of 1K and 2K resistors. Faster rise and fall times, too. Or do what UAV and Mytek's video out circuit do. Proper video DAC, with builtin R2R ladder.

     

     

  5. Posted · Edited by ivop

    1 hour ago, ivop said:

    Sort of. You can store your 4-bit samples with ora'd with $10, and then ora $a0 if you want to hear the tonegenerator, too.

    I meant #$10 and #$a0 obviously ;)

     

    Also, if you are still going on using true samples, be sure to filter them properly before downsampling. For example, if you are going to replay the samples at 800Hz, 400Hz is the maximum frequency it can capture. It's best too filter out every frequency above that, to avoid aliasing when downsampling to 800Hz. Set a low-pass filter to something like 380Hz with a very sharp knee, or run the filter a few times. After that, normalize to the volume you want.

     

    • Like 1
    • Thanks 1

  6. Posted · Edited by ivop

    Quote

    lda sample4bit

    ora #VolumeOnly

    ora #ToneGen

    sta AUDC0

     

    Is that what you mean ? 

    Sort of. You can store your 4-bit samples with ora'd with $10, and then ora $a0 if you want to hear the tonegenerator, too.

     

    Quote

    Does that have any influence on the sound quality ( produces purer sounds) ? Or is it space saving ?

    Both :)

     

    256-bytes is enough for a repeating wave to get a pure tone. The 512 bytes I use in AtariSid contains the same 256 bytes twice! That way it is easier, and faster, to index without checking for overflow everytime, at the cost of usiing double the amount of memory.

    • Like 2

  7. Posted

    You don't need to play every channel at 800Hz. Just play 4 times AUDF/AUDC, and AUDCTL, at 50Hz or 60Hz. And then have a certain RMT instrument trigger the volume-only waveform player with a certain wave. And optionaly ORA'd with a tone generator, what emkay means. This is more or less what HARDbass does. And AtariSid6 at a higher replay rate. Don't play full samples, but round-robin a 256 or 512 byte waveform, and jump around with fixed point math. And different waveforms for different volume levels, but I doubt that is necessary for bass lines.

     

    • Like 1

  8. Posted

    2 hours ago, ilmenit said:

    Comparison of different C compilers (cc65, vbcc, kickc, gcc + asm):

    https://www.videogamesage.com/topic/762-super-tilt-bro-for-nes/page/2/?tab=comments#comment-163145

    I didn't read through it yet, just sharing for now.

    Nice to see the author of the 6502 gcc backend answered, and even fixed a couple of bugs! Perhaps I should resurrect the Atari 8-bit port again, and have it merged as soon as possible, so it'll track the latest gcc sources.

    • Like 1

  9. Posted · Edited by ivop

    Yes, in Germany, around 1500, they used B to denote what we would call B♭ nowadays. C D E F G A B, where B is flat. Now to unflatten the B, there's this symbol that people familiar with musical notation might recognize: ♮, the natural sign. The unflattened B was denoted as B♮. With a bit of imagination, you can see an H in there. BH, which became H.

     

    • Like 1

  11. Posted · Edited by ivop

    ...which doesn't mean you can't order a bunch of Cherry keycaps, and have your own decals printed :)

     

    Generated gerbers and drill files. Now I must overcome my hesitance to order. I'm always afraid I made one tiny mistake ;) And this will be the most expensive PCB order I have ever done. Except for one (the VS1053 waveblaster), all my PCBs worked as expected. But still, you never know.

     

    One last look, and I'm going to order anyway. See what happens ;)

     

    Edit:

     

    shipping-options.png.78332f1c2fadda423f44b8a4eed73a8e.png

     

    Now that was difficult :D

     

     

    Edit2:

     

    project-helena-ordered.png.2ea768b38a8921b13b194b445d2130bb.png

     

    Fingers crossed 🤞

     

     

    • Like 5

  12. Posted

    Yes, ThinLTO is a compromise for always-enabled LTO. "Normal" LTO does not scale well. ThinLTO does. You were saying Syllable OS took ages to compile, so hence my suggestion to look into this :) It especially helps if you make only a single change in a 10MLOC project. You still get most of LTO, and you can compile your final version with full LTO.

  14. Posted

    19 hours ago, Sugarland said:

    Very excited to see the final product! Can't wait for the flood of replacement keyboards on ebay. 😁  Thank you for the updates.

    We'll see :) Note that it has not been tested yet.

     

    Also, I have no plans on designing new keycaps. This is meant to replace the wonky mylar with a proper PCB and reuse the original caps.

    • Like 1

  15. Posted

    2 hours ago, Kaj de Vos said:

    Compiling all those little files is much slower, so it also causes the need for incremental compilation of dependencies. I also think it blocks compilers from being able to do certain optimisations. All in all, a rather outdated architecture.

    That was fixed with pre-compiled headers, and link time optimization. Both gcc and clang/llvm do that. Cc65 does not ;)  But really, how long does a cc65 compile last anyway, even with shell and make overhead? That won't get significantly shorter with forementioned optimizations, as it is already below a few seconds.

  16. Posted · Edited by ivop

    Final version, ready for PCB house.

     

    Raytraced.thumb.png.beb03e9950a9f22ad9453a45070a00e9.png

     

    I decided to not pre-drill mounting holes, as there are different mounting frames. It's only 8-16 holes (depending on the frame), that one can drill manually, to get the best fit for your frame.

     

    I was surprised that a PCB this size (~120x350mm) is a lot cheaper than I expected. Not in the backplane computer ballpark, by far. Probably $30 for 5 boards, 1.6mm, 2 layers, 1oz, which should be good enough IMHO. And then there's shipping, taxes and custom duties. Sigh... ;) But still, something like $80 for 5 boards to start with, is not that bad.

     

    As usual, all files are on github: https://github.com/ivop/project-helena

     

    • Like 5
    • Thanks 1

  17. Posted · Edited by ivop

    More progress.

     

    492603824_XLKeyboard-MoreProgress.thumb.png.e521e2eb7d69d3e84733995ebbd6679f.png

     

    This might take precedence over the backplane computer. More or less the same cost as the bare backplane, but with a lot more functionality :) I already have the Cherry MX switches, and printed 100+ adapters in PETG.

     

    Edit: note that SHIFT_L is a 2.5U key, but somehow KiCad had no such footprint (the rest were standard). So a 1.5U is shown here instead, but properly aligned for the left shift key.

     

    • Like 2

  20. Posted

    16 hours ago, VinsCool said:

    I'm sorryyyy I tried :D 

    I actually liked the song. Never heard it before, but it has a nice melody IMHO. And the modulation (to confuse emkay even more ;)) to a different key works pretty good. It sounds like a major fifth up. That  would explain why it still worked pretty good with your diatonic tables.

     

    16 hours ago, VinsCool said:

    That's some tunes ideas... 👀

    Taking request? :)

     

    This is my all time favorite SNES game, and all time favorite SNES soundtrack:

     

    https://www.youtube.com/watch?v=IM-A6XN6COQ

     

    Better rendition, but without game images:

     

    https://www.youtube.com/watch?v=2aNHnshzGG4&list=PL124DAE5BD1B8B7F8

     

    Any tune would do :D

     

    • Like 1

  21. Posted

    Yep, I just played a round. Found some chests, kicked some behinds, found a key, a door, but no exit ;) But it looks nice, except for the flickering enemy sprites sometimes, because it seems to be using the same PM as your sword :ponder:

  22. Posted · Edited by ivop

    2 hours ago, VinsCool said:

    It really felt like a "Eureka!" yesterday, I have yet to adjust the bass to this different approach and try out more tunes...

    Yes, this turned out really great!

     

    Quote

    Looks like we all have different tastes, here I thought it sounded pretty good, and mostly accurate to the original .xm tune as well :D

    There's a note at circa 1:17 and one at circa 2:34 that sound a bit off. But the rest is SO freaking cool :) Especially the arpeggios, as I said before. They sound so nice in unison, also with the bass, and the melody.

    • Thanks 1

  23. Posted · Edited by ivop

    9 hours ago, emkay said:

    The "0 cents" usage misses the compensation of pitch differences on the scale. 

    Cents are confusing. What we were used to, the 12-TET tuning tables that were in the books and the magazines, is specifically compensated for with this alternate tuning, based on the Diatonic tuning. Having 0.0 cents difference, means it was compensated very well :)

     

    Quote

    There is also this mystery of the "late portamento" , but this might be a specific RMT issue. 

    I hear what you mean. Especially the two or three portamentos that start at a wolf note do not sound very well ;)

    • Like 1

  24. Posted · Edited by ivop

    10 hours ago, VinsCool said:

    I also wanted to experiment a bit more with alternative tunings, and this combination gave me the largest number of notes with 0,0 cents off, and also works nicely with the bass.
    It's actually pretty close to the Alternate Tuning I had been doing for a while now, but most likely even better? :P

    I like it a lot! Especially in the arpeggios you can hear how the relative distance between each note is so much better than 12-TET!

     

    Quote

    I'll attach the module and executable, as well as the tables.txt I used for this tune specifically.
    This was mostly just a test so there's nothing definitive there.
    I would like to thank ivop for the spreadsheet I used for the calculations!

    You're welcome! I do not have the patience and energy to do this myself. It's nice to see how we all work together to better the pokey sounds :) This new revival of Pokey stuff, after analmux and raster's passing, started with Synthpopalooza IMHO.

     

    Quote

    Also by some bad luck, and time wear, I broke my laptop headphones jack tonight 😕 
    That will make some future stuff a bit annoying to do...

    That sucks. There are very cheap USB "soundcards" with a headphone jack. Perhaps $3-$5 from China. But that won't help you in the short run :ponder:

     

    Edit: oh, I just now see that emkay also suggested a USB sound adapter :)

    • Thanks 1
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