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ivop

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Posts posted by ivop

  3. Posted

    10 minutes ago, emkay said:

    Sorry, but to use "fake" is an unneccesarily down pushing term. 

    Precalculation is not fake. 

    It might limit things, but those small computers have their limits anyways.

    Thanks. Hence the wink ;)

     

    10 minutes ago, emkay said:

    Seeing the Vic20 Version running at the half framerate, doing also this "precalculation" tells stories. 

    You have a link to that?

     

    10 minutes ago, emkay said:

    I'm still pissed, when people claim that "3D presentation using character mode usage" is 3D , just because the rather limited movement can be calculated in "realtime" , while doing sorted 3D movement on a real projcted screen that allows more moving in angles and positions is named fake.

    You know, I'm talking about some C64 demos that "optimize" things there, but never show "real 3D". Just some fanboy on the C64 sat the rule, so it is given ? 

    I have no opinion on this C64 thing, but even so called realtime routines use LUTs most of the time, or you are looking at a slide show. How many look up tables before it's not realtime anymore? IMHO use as many tables as needed, and that fit in standard RAM  :)

  4. Posted · Edited by ivop

    How about just precalculating everything?

     

    - subgrid of 3x3

    - 3 angles (0, 30, 60 degrees)

    - 8 (possible) cubes in view

    - 80 bytes per line, height and colormask tuple

     

    9*3*8*80 = 17280 bytes for a fake raycaster ;)

     

    For each possible cube in view, the 80-byte line descriptions are overlayed, and then filled and mirrored by Antic.

     

    There are subgrid * angles = 3*3*3 = 27 different combinations of which cubes are in view.

     

    Edit: instead of a colormask, you can also store a horizontal index into a texture. The vertical scaling of the texture can be calculated by the height value and the maximum height of a cube. Simple vertical fillers won't work anymore, and neither would mirroring by Antic, but it seems possible.

     

    Edit2: If the colormask is not stored, they are assumed to be %11000000, %00110000, etc... depending on the x position. Texture is ANDed with the mask, but is only used if height != 0. It might be helpful to store four shifted versions of each texture, if space allows that. BTW the assumption of 8 cubes in view (you are standing in the 9th cube) is based on a corridor map. If you want wider "streets" more cubes get in view.

  5. Posted · Edited by ivop

    16 minutes ago, BillC said:

    https://www.digikey.nl/products/nl?keywords=A9AAT-1208F

    Thanks! But that is way too expensive for me ;) I tried finding similar cables on ebay/aliexpress but no luck. I'll stick to ribbon/flat cables for my XL keyboard replacement project :)  With either replacing the 1x24P edge connector by a pin header, or a small adapter board (0.6/0.8mm thick) like in the 600XL. Two versions, one with the resistors for the 600XL, and one without.

  6. Posted · Edited by ivop

    Started looking at the source again. Here's where we have to be to fix or at least mitigate this:

     

    https://github.com/ilmenit/RastaConverter/blob/master/src/Evaluator.cpp

     

    There's distance_accum_t Evaluator::ExecuteRasterProgram() which returns a total_error.

     

    But there's also result_state.line_error = total_line_error; [...] results_array[y] = &result_state; for every line (y value). If you can run an evaluator similar to how all the instructions are executed starting at &rastinsns[ip++]; and evaluate if it's a problematic line, you can then possibly increase the total_line_error with a large amount.

     

    • Like 1
    • Thanks 1

  9. Posted · Edited by ivop

    Slicing on the Atari 8-bit itself is out of the question. Even a 12x12x12 model, without overhang, and no need for support, can take several seconds on a 3.5GHz octacore. That would take years on a 1.8MHz 6502, ignoring the memory requirements, and when overhang and support has to be calculated. That would take a life time, or more.

     

    Edit: but sending a properly sliced STL's gcode file from an SD Card through FujiNet to a WiFi enabled 3D Printer could work I think.

     

    Is the ChromaCad format known?

    • Like 1

  10. Posted

    2 minutes ago, drpeter said:

    The latest version of RastaSlide produces annotated disassembly of RastaConverter .xex files, highlighting lines which will produce the known <=5 cycle write window bug

    Now that algorithm to detect bad lines has to be added to the evaluation function of RastaConverter, and then evaluate minus very bad ;)

     

    How does RastaSlide detect lines with the known write window bug?

     

  11. Posted

    Do you know how to fix this in RastaConverter in the first place?

     

    Perhaps one can detect the specific loads and stores within a 6 cycle window (not too many combinations I think), and then evaluate that particular kernel line as pretty bad in the late hill climbing sense?

     

  13. Posted · Edited by ivop

    12 hours ago, Bee said:

    Without getting into too much tech detail, I can do 90% of my FDM printing on this:

     

    https://www.monoprice.com/product?p_id=21666&gclid=Cj0KCQjwkZiFBhD9ARIsAGxFX8Avanpr-l7pJMgCporQz0CI-fVG2XFQxaIy3ubt-NKwm2HGy3yBndYaApnbEALw_wcB

     

    Also a nice entry printer.  Delta printers are a diffrent branch of printing.  This, pull it out plug it in, pretty much pain free on the Hardware side.

    But the print volume is only 11x12cm :( On the other hand, I have an older Monoprice clone (Prima Creator, 12x12cm) which worked pretty well, until the temp sensor shorted itself and took the whole controller board with it. Not protection at all. You get what you pay for, I guess :)

     

    Edit: Seems it has Auto Calibration (I assume auto-levelling). That's nice. I don't think I'll ever buy another 3D printer without it.

  15. Posted · Edited by ivop

    Still waiting on the flat cables and 4051s...

     

    helena-1.thumb.png.1efb070b1efafd57a38d18a89213b8b7.png

     

    helena-2.thumb.png.f9fe9c97f57a97affce3350dab36ddfa.png

     

    helena-3.thumb.png.64112ab8f47fe14fda0cebb5a4ee2758.png

     

    helena-4.thumb.png.77b479ed0f4c14b7156abef1de0a65a1.png

     

    There's some lens distortion. ESC/TAB/CTRL/SHIFT do not overhang the PCB.

     

    Another lesson learned for REV B: 3 pin Cherry MX switches are hard to get properly aligned when soldering. Replace with 5 pin footprint, which can accomodate both.

     

    Edit: I fixed the C key after I took the picture. That's not lens distortion ;)

     

    • Like 5

  18. Posted · Edited by ivop

    5 hours ago, Mazzspeed said:

    These machines are meant to be enjoyed, not locked in glass cases.

    This. Similar to boxes. I have a boxed 800XL, which is almost brown by either smoke, UV, or a combination of both, which I got in a pretty nice box. I was thinking, I can put that somewhere in the "attic", but I can also put the box on display at the top of my bookcase/cupboard, and enjoy it every day :)

     

    And that's next to the framed patent document of my avatar, which I once got as a birthday present from @SenorRossie :)

    • Like 1

  19. Posted

    That could well be the case. But based solely on the zip code, it should never have went to NY :) 

     

    The XL Keyboard PCBs I ordered in recently, went from China to Japan to Belgium (very near to the Dutch border, but instead went) to France, and then finally to The Netherlands :) Their logistic algorithms are a mystery to me. When I finally touched the PCB, including its destination, it has been in five countries :D

     

    • Haha 1

  20. Posted · Edited by ivop

    Agree with mytek. BITD, he used this top part of the case as a "remote" keyboard with a meters long flat cable. I was very impressed how he sort of folded a new bottom for it :) (out of alumin(i)um)?

     

    Only one thing, it's not Python code, but C. And you could have removed the black/brown part of the top half, before spraypainting, without having to mask it with tape. If you carefully heat the badge, you can even remove that with a precision knife.

     

    But all in all, nice project! 👍

     

     

    • Like 1

  21. Posted

    8 hours ago, emkay said:

    Due to the fact that Pokey mixes the voices in a simple physical way, it is better to have the basses slightly off, put the other channels to a volume where they mix to the resulting frequency. 

    The detuning comes mostly from the randomly appearing peak orbit. It sounds louder than the rest. 

    There are methods to put those unwanted peak orbits towards 0% of appearance. 

    You might know: Pokey has the "random" polycounters, but they were not really random. 

    If you check a tune , you can replay a pattern and listen to the notes on the track/pattern.

    Using that for now in RMT gives different results than LZSS with all optimizations.

    You are mixing up volume, timbre and frequency (i.e. tuning).

     

    8 hours ago, emkay said:

    @ivop

    I know that tune ;) 

    The arrangement sounds clean, but I also pointed to the "late FX" in  the tune, and the musical flow doesn't really work.

    I like what you call late FX, and the musical flow is tremendous, and I have gotten used to the modulation. That is modulation in the music theory sense, i.e.going from one key to another. Not like how one channel modulates another one.

     

    8 hours ago, emkay said:

    And of course I was about PAL Ataris when I was pointing to the 440Hz . 

    For NTSC the 443.9Hz solution is better. the 60Hz replay is also a huge benefit .

    My point was not the 443.9Hz solution. It's obvious that PAL needs another frequency for the A note that everything is based on. My point is that theory has finally putten in practice, and that a mixture of the diatonic major and diatonic minor scale work a lot better than the 12-TET tables that were in the magazines and books. That's for the key of A major now (plus related keys, like F# minor). In the end, we need 12 tables, one for each semitone in an octave. After that, you only need to figure out in which key your song is, and use that specific table.

    • Thanks 1

  23. Posted

    8 minutes ago, emkay said:

    really, why don't people blame the tune that is used in AtariBlast at 1st? The basses were totally off, but people liked it. 

    Oh, but we're not all the "people" you refer to. You showed several examples of recent games that had indeed awful music that went all over the place. Even out of tune arpeggios.

     

    But that's not the point when Mr. Fish points out one of your tunes is excellent (which it is), and the other is ehm.... not so much :)

  24. Posted

    5 minutes ago, emkay said:

    You still won't get it. do you ?

    WHAT?!?!  It's still you who doesn't know what tuning really means. Why this stab at Vinscool?

     

    5 minutes ago, emkay said:

    The 8 Bit resolution is fairly enough, if the tones  have been tuned to the 440Hz rule. IN ALL CASES.

    NO! If you use dist C basses, you have to tune your other distortions to the bass! Otherwise, your melody and chords will always be out of tune in regard to the bass, because the tuning of the dist C basses is fixed, and not necessarily 440Hz 12-TET, which you seem to think.

     

    Vinscool has proved already that tuning to 443.9Hz on NTSC, and use a diatonic tuning, it sounds way better. Almost indistinguishable from a YM/AY with 16-bit resolution.

     

    5 minutes ago, emkay said:

    The rest can be done by using the PWM and the careful use of the "Bass Polycounter Orbits".

    That sounds like fix it in the mix (audio technician lingo), which is never a good idea if you can fix it in the first place. Which you can, with proper tuning. Vinscool understands that.

     

    Do you know the difference between a key (musical theory, not the physical piano key), a scale (major, minor, lydian, arabic, etc...), chord formation (sixth, sevenths, add9, sus2, etc..), and tuning (Pythagorean, diatonic, 12-tet, etc...)? This is not meant to offend you. Really, do you know? If not, read up on it. It will really help in communicating about music, especially concerning the limitations of Pokey, and how to work around them.

     

    5 minutes ago, emkay said:

    What is missing "for the perfection" is the possibility to hear the changes directly. 

    That's true! :)

     

    • Like 1

  25. Posted · Edited by ivop

    Small update:

     

    I have cut another two boards. Hacksaw was so easy (there's a line on the silkscreen), so I didn't try a boxcutter.

     

    It is based on the AWC (with oldskool Cherry switches) circuit board. It fits perfectly. Only need to drill 8 holes, all in the border of the PCB.

     

    Also checked a Stackpole frame. Fits nicely, too, but apparently the LED is not at exactly the same place, but slightly lower now. That's not really a problem, and can be mitigated for when soldering the LED, if that's necessary.

     

    There are two other problems to overcome with the Stackpole-all-metal frames. One is to avoid the PCB shorting itself against the metal frame. Two is how to attach the PCB to the metal frame. The screw holes are at completely different places, and used to screw into that all-plastic frame that held all the keycaps and springs to press against the mylar.

     

    Contrary to the AWC boards, the screws come from below and need to attach itself to the PCB. Very carefully find the spots where it won't bother a switch that's soldered to the PCB. And to solve problem one by placing small pieces of self-adhesive rubber between the metal frame and the PCB.

     

    I'm also considering Velcro to solve both problems at once. Seriously :D

     

     

    Edit: oh, and the small update is that I'm waiting for longer flat cables to arrive. I thought I had them, but the longest were just 10cm :( BUT I had already ordered them a week ago, so I hope they'll arrive shortly. Also ordered a bunch of 4051 ICs. Just to be sure.

    • Like 2
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