PSG potential

Page 2/2
1 |

By kanima

Master (194)

kanima's picture

13-06-2003, 16:58

Matra used non-conventional waveforms on PSG such as sawtooth (a trick using the built-in LFO/EG), 4bit sampled instruments, etc.

Does anybody know where to get some info on both these tricks? I.e. sawtooth and 4bit samples?

By pitpan

Prophet (3152)

pitpan's picture

13-06-2003, 19:40

About sampled sound, have a look at Ricardo Bittencourt's excellent article fount at http://www.map.tni.nl

He's got also some useful tools to deal with WAV and convert them to MSX usable format.

Kind regards,

Ed Robsy

By anonymous

incognito ergo sum (116)

anonymous's picture

14-06-2003, 14:34

The correct URL is http://map.tni.nl/

By pitpan

Prophet (3152)

pitpan's picture

15-06-2003, 12:59

Ops! Sorry for any incomvenience...

By the way, I've been coding hard these last two days, and I have done a sample editor to be included in a MSX tracker. It allows to edit 32 step samples, adjusting envelope, noise frequency, mask for both effects and tune modulation. Sounds quite well for a simple PSG thinggy. It's somewhat based upon SoundTracker for ZX Spectrum.
In a few days I will put it on-line in my own page.

Kind regards,

Ed Robsy

By snout

Ascended (15187)

snout's picture

15-06-2003, 22:24

Sounds like a very interesting development! Smile

By Maggoo

Paragon (1216)

Maggoo's picture

16-06-2003, 10:02

Ops! Sorry for any incomvenience...

By the way, I've been coding hard these last two days, and I have done a sample editor to be included in a MSX tracker. It allows to edit 32 step samples, adjusting envelope, noise frequency, mask for both effects and tune modulation. Sounds quite well for a simple PSG thinggy. It's somewhat based upon SoundTracker for ZX Spectrum.
In a few days I will put it on-line in my own page.

Kind regards,

Ed Robsy

I had no idea the ZX Sound Tracker could use samples but that ideed would be a very good thing to have such a tracker ported to MSX. PSG rules Smile

Keep us updated on your progress.

By pitpan

Prophet (3152)

pitpan's picture

16-06-2003, 13:16

Well, indeed they are not real "samples". They are a combination of 3 series of data: amplitude envelope, noise frequency and tune modulation (signed offset).
So, a sample is played for every note using these 3 modifications affecting it. The replaying speed for a simple sample is 50 Hz (PAL) or 60 Hz (NTSC). And it can be up to 32 steps long.
Old good Gremlin Graphics games used this feature for its impresive intro songs (remember MASK2 or AVENGER?). And I think that also MATRA's excelent songs for the PSG use this feature.
A lot of interesting effects could be produced enabling/disabling tune and/or noise channels, and combining all the different effects. Detunning can also produce interestings sounds. And using all this is possible to simulate vibratto, tremolo, fake different bass sounds, etc.
As soon as I finish with the SAMPLE EDITOR I will start with the ORNAMENT EDITOR. With these two base programs I will mix them and add an editor to produce a complete tracker for the MSX system. PSG rulez! AY-3-8910 forever!

Kind regards,

Ed Robsy

By snout

Ascended (15187)

snout's picture

16-06-2003, 18:54

AY-3-8910 forever!

amen Smile

By nf

Supporter (4)

nf's picture

21-07-2003, 19:26


I also heard about pseudo-8bit samples playing (you can check it in some Bandwagon demos). Atari users use the PSG (they called it simply 'Yamaha' chip) to make that kind of sounds. Perhaps yo should ask Atari ST coders/musicians for this sampling technology on PSG.

Hey,

That's true and for the last demos (more speficially Vesikauhu), the samples were played realtime. The thing worked really simple. We had a sample playing at 8000 Hz and an effect refreshing at 50. So I'd

1. Play 160 bytes of the sample (=8000/50).
2. Dump one byte to the VRAM.

And so on, until the screen is finished. It was surprisingly easy even on the MSX1. 3.57 MHz is a lot of CPU power, really, when you hog the whole CPU to yourself. Too bad no-one seemed to notice our little trick. Wink

Page 2/2
1 |