Dedicated Sound

[DigiTan]

I was having a conversation with shadowing a while ago and it got me to thinking about having some sound or even music in the game. I know talk of music in calc games usually conjures replys like "when pigs fly" and "...cold day in hell," but I'd definately like to see this work.

In-game sound is out the window because it would ruin the game speed, but basic sound effects and menu music might be doable.

I'm going to try a brief unrelated project to see if poly-phonic MIDI-type of sound can be done. This kind of thing has been beaten to death on HP-49G, but I want to test it with a TI.

Anyway, what do you guys think about sound or music? Would it help the gaming experience in Sonic?

[shadowing]

Yup. Sound and music is what made everyone want to got FAST!! AND BUMP INTO EVERYTHING!!

It's all about the music.

[leofox]

Music would be awesome. Though most people aren't able to use it... I can, fortunately, cuz i have a converter cable and a 2.5mm headset.

[DigiTan]

I guess I'll give it a try then. I talked to some DS guys and it looks like it can achieve ~almost 4 octives (up to 768hz) if you use the 83+ interrupts right. I was hoping for 2 octives, so that's great news. All the (genesis) Sonic songs I know had at least 2 or 3 melodies going at once so I'm gonna try to see if it is possible to mix the audio melodies.

[Mike_k]

If you happen to get an engine working, try setting up an interrupt that plays a note every few seconds and see how much it taxs the processor.

-Mike

[DigiTan]

I guess I'll try both approches eventually. It would be awesome if we could have in-game music, but I think we'd have to settle for title screen/menu songs to get the best quality. The big problem is mixing. Today, I'm going test this strategy called "1.5"-bit sound, which I'm hoping will allow us to mix 2 or more melodies. Also, I'll look for a MIDI program that can convert the sound to sheet music so I won't have to "compose" the song all over again.

[shadowing]

Now we just need to convert it. Too bad i have no clue how sound and music actually works.

[Brazucs]

I think they have a tutorial somewhere on ticalc.org. I'm gonna try to make the Mario song, I think it would sound awesome!!

[shadowing]

Digitan, make the fast theme of the sonic song. It's always the song!!

[DigiTan]

Okay. Last night, I hopped in my time machine and found this TI-85 MIDI program from 1996. It can play any tone just as long aas you send values for the tone and duration to the HL and DE registers. With some creativity, you can use strings to run it in a loop and play an entire song.

The code works great but there are a few limits. First, it's not stereo, it's mono. Second, you can't do anything else while a tone is in progress--you can't even do interrupts or text. And third, the duration is based on wave cycles and not real time, so your low tones will play way longer than the high ones.

But there's good news too. The code is very lean, so we can probably get up to 8 sound octives and still have time to do other processor stuff. I don't know how many octives a piano has, but I'd guess it's really close to eight. A 83+ SE version would have even better capabilities.

Anyway, I'll keep this code (it's cool) and try to find some way to split the processing time between sound and the main program. Also, I'll try to find some way to mix the tones without a ton of distortion.

[edit]

Also, I'm in the process of converting some Sonic 1 MIDIs to sheet music. Starting with the Green Hill Zone. Any other requests?

[shadowing]

Every song there is. I'd say that.

[MissingIntellect]

Just want to note that you don't need a converter for headphones to listen to sound...Just set your radio to a blank channel and hold you calculator close to it.

[DarkerLine]

You wouldn't NEED 8 octaves either, most likely.

[Madskillz]

ha ha, yes the very simple and cheaper way! Provided you have a radio at with you. When I bought my cell phone, they threw in a 2.5mm ear piece. I remember when I went to radioshack and bought all the parts needed to make a sorta speaker type thing...with the buzzer and such...I think I still have it! I remember listening to some star wars song.

Anyhow, sound is a real cool idea.

[DigiTan]

Okay, I made a tiny prog called "tone.asm" that can play basic sound. I'm going to try and come up with a version that can divide processor time between the sound and the game without using interrupts (they're too slow). So far, I'm using the R register as a timing source. So instead to using a continious loop, you just switch the sound port, do the game code, re-check R periodically, and switch the sound back when R rolls over to zero.

With this strategy, you can play any vocal note in the vocal range with well over 99% accuracy, but there are still some problems...

* VTI's sound is not 100% true-to-life
* Sometimes R double-increments
* You have to check R every 54 instructions, on average (hardly time for 1 sprite)
* If you don't check R often enough, the note will "crack"

Also, I was going to try controlling the volume the same way they do grayscale graphics (pulse width method), but it looks like that strategy doesn't apply well to sound. Anyway, I'll try to do a basic song string this week and record it as a .wav.

[edit]

Does anybody know a good website for PC speaker music?

:| What?

[axcho]

What program do you use to edit MIDI files, or at least to write sheet music? I can't find a free one. If you want help with the Mario songs, I've figured some of them out on the piano. No chords, though, just two voices. Since I don't actually have the games, the harmony or bass part isn't exactly the same as in the games. Let's see, I've got the Mario theme and some other songs from Super Mario, along with the songs from the castle and the first world for Super Mario 64. Yay, I'm so cool!

If you need fast music for Sonic, I have transcribed the first chorus of the Coltrane solo on Giant Steps. That would be cool, or at least funny.

[DigiTan]

Right now, I'm trying MidiNotate Musician 1.0 from notation.com. I haven't installed it yet, but it fits the description for what I'm looking for and it came in a 30-day trial. Basically, I want to look at these midis and come up with frequencies for the melody and counter melody (maybe percussion too).

Today, I updated tone.asm to divide processor time using the R register and so far it works...sort of. The tones are way lower than expected so that throws off my earlier calculations. The tones aren't consistant, and also most ROM calls will cause sound errors and produce an ugly growling sound. I'm looking to see if I can use CPU cycles instead of R.

[DigiTan]

Alright, the ditched the whole tones thing and had a new idea. I'm going to try and record MIDI instruments one at a time, and try to play them back on the calc with playwav. After that, I want to make a program that can immitate those instruments and play them back like CalcMOD does for tones. Basically, it would be a cross between playwav and CalcMOD. So far electric guitars and low notes in general have to best quality.

[the_unknown_one]

Why cant you just search the Sonic source, take the songs out of it, convert them to calc type and then use a routine to play them? Joking

[DigiTan]

Heh Heh. Actually, I sort of did that exact thing about 14 hours ago. Basically, I recorded a few Genesis songs straight from an emulator. Then I used Windows Sound Recorder and wav2db.exe to convert it to calc data! I was able to record up to 27 seconds of any one song.

Here are the recordings. I filtered out signals above 2000Hz, because my prog will only have a range of 1064Hz when it's done, and VTI was producing lots of noise well above that range. I'll explain why the second wav is quiet below...

* Sonic the Hedgehog 3 : Competition Menu
- Original Audio [last 27 seconds of song]
- Calc Audio [micro-pulsed (very quiet)]

The second file was volume-controlled by the calc. Basically, instead of using normal square waves that are long (and hurt your ears) like playwav and CalcMOD, I used small audio pulses. The pulses are too sort for the speaker to reach full effectiveness, so you don't get full volume. Their shortness also puts them out of the human hearing range--so you hear the groups of pulses, and not the individuals. If my guess is right, you can widen the pulses to get 27 different levels of volume without making the mini-pulses audible to the people.