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About jltursan

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    Star Raider

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    Madrid, Spain
  • Interests
    Old vintage computers!

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  1. Way cool!, can it run at 100% speed?. If it can run on a TTGO-VGA32 you can benefit from their PS/2 and VGA interfaces 🙂
  2. The "end of frame" trick is easy to achieve, the real problem is starting in the beggining of the visible frame and keep the execution in sync with the beam every line until this end of frame. Check this thread: Seems that there's some kind of RAM contention and you can't sync the execution using a fixed amount of CPU cycles every line. I really hope that MackJsy can find a way to overcome this; indeed their TRS-80 experiments in the page you've pointed out are what I'm trying to get changing Aquarius' color attributes on the fly. Of course I can keep testing; but even with my MicroExpander, it's a PITA to manually tune the cycles of every scanline and load the code in the Aquarius to debug it. I reached about 16 scanlines tuned; but it's exhausting, definitely I need to find a pattern.
  3. Yep, I know it, it has a nice scroll 🙂 Although extremely limited, the VZ200 has a bitmap resolution of 128x64 with four colors (2 palettes available) and that's a key feature to have at least some graphics moving freely in the screen. The Aquarius can use a pseudo-graphics resolution of 80x75 (if the full 25 rows are used) thanks to some chars of its set, as shown in the scroll demo; but with only two colors every char (2x3 bloxels). Sprite movement could be achieved in 4px step with some color bleeding or 8px (a full character width) without color bleeding. Of course it could be a funny experiment to use not only the "bloxels chars" and use every character available in the font set; but then you're forced to use 8px step movements. Having a better timing knowledge of the Aquarius, a higher color resolution can be achieved, check Multicolor engines for ZX Spectrum, where you can easily get about 64x75 bloxels each with its own color, a bare minimum to get some nice results. EDIT: ...but if you try to forget about the so-called bitmap graphics and think only in text modes with 8px movements, what you can get?. As point out years ago, the incredible Mr.Furuhata MZ-700's games: Side Roll F or Eugea are real examples to follow. The Sharp's character set is a bit more flexible; but with some care, the Aquarius font could serve well, Aquarius Draw is a great tool to practice 🙂
  4. Indeed, or at least a TMS VDP machine, the palette colors match.
  5. Uh?, you mean Cauldwell?, the Aquarius as a MPAGD target?, I can't imagine how a heavy sprite-based game engine can be ported to it. Do you know more about Jonathan plans?. I've been also trying to increase the color resolution of the Aquarius to add some "pixels" to the screen; but found that right now, it's a nightmare to sync with the beam due RAM contention and lack of information about this.
  6. Daedalus2097 is right, the next step to check is the Agnus chip; but beware, visually inspect its socket and look for cracks and if you extract it, do it very carefully.
  7. So, if the caps lights multiple times, system is mostly working. Do your hear the constant clicking of the floppy drive? Piggybacking could work, just be sure none of the RAM chips are too hot to touch. If they're mostly cold, you can piggyback a good-known RAM IC and check for changes in the image. Btw, you have unplugged the RAM expansion, isn't it?. And indeed, reseat all socketed chips and check also if there's some rust.
  8. You can also think about the PiStorm, you'll get the usual acceleration + RAM and also there're future plans to add a combined RGB and RTG video signal through HDMI. The only drawback is its lack of maturity, it's a bit too soon to judge this little beast.
  9. Seems you've some kind of RAM problem, any of the 16 RAM ICs are faulty or there's something wrong in the related circuitry. If you hear the aforementioned floppy clicking at least could mean most of the computer is working. Can you hit caps key a couple dozen times and check if the led lights on/off all the time?. Of course ROM/Kickstart could also be faulty, it's the source of the image being displayed...
  10. Glad to see your here! mdlz80optimizer is evolving fast and right now I really think that it's an invaluable tool for Z80 programmers. Santi is giving a constant support and adding features as fast as he can, he just need the right feedback and help. I've found that it's not only optimizing the code; but also giving me nice ideas and teaching me about how to get the most of the processor, it's indeed a funny experience 🙂
  11. Ouch!, guess i better don't ask why...🤔
  12. Is this project still being worked on?, the ADAM kit big brother sounds great...
  13. Justa shot in the dark; but can be the Matra Alice 4K, the french PAL MC-10, a perfect clone including schematics?, if so, there's a lot of info here: Alice en détail
  14. All players I've seen always write the registers in a sequential order, no fancy tricks. I guess the writing is so fast that it can't cause any audible glitch.
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