201 Reply by utz

(18 replies, posted in Calculators & Pocket Computers)

Ok, so what's the current state, you got things rolling on the 83+ but not on the 83?

DJ_CYBERDAD wrote:

How do I install the drivers for the Silverlink cable in Windows 10?

**EDIT....despite TILP being recommended, it does not work, because there are no drivers for the silverlink cable that work with this software for Windows 10....

Problem is, there was no Windows 10 when this stuff came out. And then Microsoft made damn sure things will be hell for 3rd party devs who need access to lo-level stuff and don't want to pay $$$ for an agreement with them. Anyway, to make your current setup work with TiLP,  you need to carefully follow all the steps in this guide: https://github.com/debrouxl/tilp_and_gf … ADME.win32

DJ_CYBERDAD wrote:

I am utterly confounded as to WHY when designing an OS for a MOUSE-LESS system, they would give it a cursor and click interface... WHY??

Now that is also beyond me, lol.

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202 Reply by utz

(18 replies, posted in Calculators & Pocket Computers)

Don't install TI-Connect and TiLP at the same time, that's not going to work.
Unless you are using a TI-82, you can theoretically just use TI-Connect, though I faintly recall someone reporting problems with TI-Connect screwing up the HT2.*p files. I'd say give that a try first though.

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203 Reply by utz

(13 replies, posted in Atari)

xxl, what is the timing for the interrupts? If we had some fast interrupt reset CONSOL each scanline, for example, then this could actually be useful for PCM/pulse-interleaving playback.

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204 Reply by utz

(13 replies, posted in Atari)

Awesome, thanks for the hard work and the great write-up, Shiru. And not least congrats on composing such a kick-ass tune.

I faintly remember trying to code something for GTIA some years ago and also being frustrated by the not-so-stellar documentation available. I wonder if there are any GTIA-specific tricks one could pull here. The basic mode of operation is to write a value < 8 to 0xd01f to set the beeper on, else it's off, right? Did you discover anything beyond that?

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205 Reply by utz

(42 replies, posted in Other Platforms)

Wow, what a massive package. Thanks a lot for all your hard work!

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206 Reply by utz

(43 replies, posted in Atari)

I'm sorry, but I won't make it. Too much stuff going on right now.

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207 Reply by utz

(2 replies, posted in Sinclair)

Absolutely massive composition, mate. Somehow I can never force myself to polish 'em so much.
Also lol @ "This is from the Pentagon 128, a Russian Spectrum clone that was fan made." Where do these people come from.

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208 Reply by utz

(43 replies, posted in Atari)

Thanks for the reminder! Would have totally forgotten about it, since normally SV happens towards the end of the year.
I'm tempted to join this and maybe also 2600 msx, but I'm not sure I'll have time to make something.

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209 Reply by utz

(11 replies, posted in Other Platforms)

Ah, now I understand a bit better how you want to generate the different volume levels.

2) You can specify high/low thresholds for pcm2pwm, ie.

$ pcm2pwm sound.wav hi lo

where hi and lo are 8-bit unsigned integers. Default is hi=252, lo=3. Lowering hi and raising lo will make the converter more sensitive.

3) To get rid of the parasite tone (3903Hz), mixing frequency would need to rise above the audible range. So ideally you'd mix at 20KHz or more. On Spectrum we usually mix around 15KHz, and rely on hardware filtering/smoothing to take care of any remaining noise/whining. Beware that emulators introduce additional noise, depending on how they implement sound. MAME's MZ-700 suffers from this, for example.
4). Let me try to construct a basic example. Late night coding attempt, and completely untested, but the idea is to do something like this:

; two-channel OR mixing (aka Squeeker method)
  ld hl,0        ; reset oscillator 2 state
  ld de,div2     ; osc2 clock [freq = sample_rate * div2 / $10000]
  exx
  ld hl,0        ; reset osc1 state
  ld de,div1     ; osc1 clock
  ld bc,ring_buffer   ; must be aligned to 256b page
  
loop
  add hl,de      ; update osc counter channel 1
  ld a,h
  add a,$e0      ; $100 - duty ($e0 = 12.5%)
  ld a,$27
  adc a,0        ; if duty threshold exceeded, A is now $28 
  exx
  add hl,de      ; same for channel 2
  ld c,a
  ld a,h
  add a,$e0
  ld a,0
  adc a,c        ; A is now $27, $28, or $29
  exx
  and #28        ; mask bits, A = $20 | $28
  ld (bc),a
  inc c
  jr z,loop

PS: You should be able to change your nick now. Let me know if it doesn't work, then I'll change it for you.

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210 Reply by utz

(11 replies, posted in Other Platforms)

Great to see some in-game 1-bit music action, and also great to see the MZ-700 getting some love! Tbh I think it actually sounds surprisingly decent considering the sample rate.

There are some people on here that know more about 8253 wizardry than me, but a quick couple of thoughts:

- Beware of the Nyquist limit, ie. the highest frequency in the audio may at most be half of the sample rate. So if you replay at ~2Khz, you should apply a low-pass filter with a cutoff of ~1KHz before resampling.
- pcm2pwm isn't very well suited for harmonic content. Its main purpose is to encode percussive sounds in a very size-efficient manner.
- I'm not sure intersective PWM is worth it. In order to produce decent results, it requires a very high sample rate (likely at least 80KHz), which would be pretty hard to pull off on a 3.5MHz Z80 machine.
- It is possible to mix multiple channels without volume control. A method that works well at low sample rates is to have 2-4 pulse wave generators with a duty cycle below ~25%, and OR their outputs together (example).

Anyway, thanks for the detailed write-up, looking forward to hearing more from your 1-bit endeavours!

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211 Reply by utz

(2 replies, posted in Calculators & Pocket Computers)

Hehehe, sounds like you're having some good fun with this thing big_smile Great "experiment", keep 'em coming wink

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212 Reply by utz

(3 replies, posted in Sinclair)

Ohhh yes! Such a heavy bass. Another great milestone on the way to perfecting that Tufty™ style.

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213 Reply by utz

(7 replies, posted in Calculators & Pocket Computers)

Ah, the fluctuation isn't that bad. When batteries are 100% full the clock rate drops quite quickly, but around 80% you can probably hand-sync for quite a while.

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214 Reply by utz

(6 replies, posted in Calculators & Pocket Computers)

Yes, it'd have to be a rather minimalist cover. Though you'll find that 6xx/9xx + 8xx/Exx can get you surprisingly far.

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215 Reply by utz

(7 replies, posted in Calculators & Pocket Computers)

I haven't tested with a 84+SE, but I doubt it's worth shelling out $100 just to try. Tbh I don't think the SE's hardware is much different from the original 84+. And afaik the standard 84+ is not timing stable.

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216 Reply by utz

(130 replies, posted in Calculators & Pocket Computers)

Unfortunately it's not avoidable. It's a major flaw in the design of HT2, but I didn't know better back then. I wish there were an easy way to fix it, but basically the only way would be to rewrite like half of HT2 from scratch. Maybe one day, when I have too much free time, lol.

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217 Reply by utz

(7 replies, posted in Calculators & Pocket Computers)

Correct, the only way to properly sync with matching pitch would be do a hardware mod and replace the timer crystals with something more stable.

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218 Reply by utz

(6 replies, posted in Calculators & Pocket Computers)

Well done, I like it indeed! Looking forward to hearing more from you. I'd be interesting to see if you could pull off some of the more glitchy/breaky Aphex Twin tracks.

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219 Reply by utz

(7 replies, posted in Calculators & Pocket Computers)

It's unfortunately impossible to tune HT2 properly, because the calculator's clock speed (and consequently, HT2's pitch) will vary depending on battery strength. Also yes, different models tend to have different speeds to begin with, but battery strength has the biggest impact. A will be 440Hz if the calc is running at the 6MHz it's supposed to run at. Which, in practise, is almost never the case.

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220 Reply by utz

(1 replies, posted in General Discussion)

This ultra-dirty sound you're going for is great. Still in love with the guitar especially. Would you consider recording a metal song maybe?

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221 Reply by utz

(3 replies, posted in Other Platforms)

Beautiful compositions, very enjoyable. Think I've seen that name before somewhere, can't point my finger to it, though. Certainly not on beeper. Anyway, thanks for sharing, Shiru.

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222 Reply by utz

(2 replies, posted in Atari)

You have the Mata/Qieta stuff and Mister Beep's old works, I guess? I don't know any other (beeper specific, at least). Nowadays nobody uses it anymore since we have zbmod which does the same but much cleaner sound.

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223 Reply by utz

(2 replies, posted in Calculators & Pocket Computers)

Hi and welcome aboard! Good job on your first HT2 track. Of course there's always things that can be improved, but I think this is actually pretty solid. For being new to trackers, you certainly didn't chose the easiest route wink

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224 Reply by utz

(13 replies, posted in Other Platforms)

That's a pity. Well, at least we're getting this excellent music release. Anyway, thanks for the good read. Looking forward to the upcoming ones, especially the data format one. I'm also curious about your experiences with VIC. Writing a player with support for "viznut" waveforms has been on my bucket list for a long time. Sounds like I might be in for some nasty surprises, though.

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225 Reply by utz

(13 replies, posted in Other Platforms)

Ahh yes! Fantastic work. Still blows my mind that monophonic stuff can sound so great.

So he didn't use your music in the game after all?

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