the basic MSX soundchip - BASIC "Sound" command

Supporter (4)

05-11-2006, 11:30

Hi all,

i'm one of the thirty-something guys who used to have an MSX-1 (Sony with 16k)
and even then I was already very interested in the sound-command.
Unfortunately after 20 years I forgot all of it and i don't have the machine nor
the books anymore.

I used to have a program on tape from a zine, this program showed a screenfull
of parameters to tweak for the soundchip. it was like playing with an analogue synthesizer , only without the keys

Does anyone have a good guide on the Sound command (NOT using the special
sound cards like SCC or MSX Audio)
When I try to use it i mostly get "illegal function call"s.

I tried "googling" it but it's a dead end. most of it is related to the soundcard extentions.
or in Assembly and not comprehensive enough.

Thanks!

By AuroraMSX

Paragon (1902)

05-11-2006, 12:04

The SOUND command directly sets a value into a PSG register.
Basic syntax for the SOUND command is

SOUND <register>,<value>

Where <register> is in the range of 0 upto 15 and <value> is in the range of 0 upto 255.
The Wikipedia page for the PSG contins a lot of links to resources for your reading pleasure.
Happy MSX-ing!

(sorry, /me too lazy to write a complete PSG tutorial right now ;))

By Udo29

Supporter (4)

05-11-2006, 12:08

Thanks! this is one step closer, i'll just have to pick my own technical brain and
see what I can come up with.

cheers!

By pitpan

Prophet (3156)

05-11-2006, 12:10

Get the PSG doc at http://www.robsy.net/ay38910.pdf or check the PSG part of the excellent MSX Red Book, that you can grab at http://www.robsy.net/tredbook.txt

Of course, I'm afraid it is not very straightforward.

By Edwin

Paragon (1182)

05-11-2006, 12:22

You can also download SEE (from here). It's basically a front-end to the PSG registers with a few extra commands. Useful to help get a feel for it.

By djh1697

Paragon (1736)

05-11-2006, 19:56

The play command is really easy to use.
Play "abc" will do just that!

By Udo29

Supporter (4)

10-11-2006, 18:31

Edwin, the SEE program doesn't seem to work on BlueMSX, i get a good logo but the tekst display
is scrambled. trying to tweak the settings of BlueMSX but no luck.

Anyway, for the moment i'm looking for assembly code to make a sinus wave, then gimme 2 more years to make a synth with LFO and arpegiator