[sdiy] How to make wavetables? What size?

[harrybissell]

The Wiard eprom tables are 8 bits wide x 256 bytes long.

You just scan through them sequentially.  Changing 'banks'
or 'waves' involves changing higher order address bits.

I used Grant's software to generate tables that are 128 bytes long...
and stole back one of the address lines to allow twice as many waves, half
as long.
This is for scale quantizing so my use is different than yours.

The MiniWave does not run from a VCO at eight times the frequency (not 256
times as you said earlier)... but in effect acts to multiply the frequency
of the
incomming wave.

I also used Grant's software to make some eproms for Ken Stone's wavetable
module... but I also hacked Ken's design to increase the number of address
bits
to seven.   Even so... its easy to just arbitrarily set a limit in your
head as to where
one wave should stop and another begin in the software.  One ONE screen of
Grant's
program... draw TWO waves and that will work with seven bits.  Draw FOUR
and it
will work with six bit addressing.

Its just more of a pain-in-the- at ss to make the waves...as the built in fill
patterns will
be wrong.

H^) harry

Metrophage wrote:

> Hi Nate -
>
> Yes, it is a nice tool, except that I don't know how to make a circuit
> for 256 byte tables! It'd be easier to do-it-myself if I knew what I
> was doing! >;]P I do have the Wiard app around here somewhere. As I was
> saying, various circuits expect the ROMs to be organized in different
> ways - they are not all cross-compatable. I am sure that the basic
> principle behind the Wiard app is simple, but the GUI probably removes
> some of the tedium of writing the stuff in a text editor. I can endure
> writing it all out, I just don't know how to format the data. Most
> software which I have played with tables are just lists of frequencies
> in Hertz, I don't know what kind of numbers a plain DAC0800 is
> expecting.
>
> Probably a lot of "obvious" stuff I am missing, but I'll make sense of
> it!
>
> CJ
>
> --- nN AAt     e     e <timexheater at comcast.net> wrote:
> > dig around on the wiard site... they've got a really nice wavetable
> > tool for
> > making the raw waves. if you can't find it on the site i might be
> > able to
> > dig up the link somewhere.
> >
> > or like you said, just use the rom from something else :P
> >
> > - nate
> >
> > > I guess what I am wondering is if there are any opinions about how
> > many
> > > bytes to use for my waves, and how to make the tables themselves!
> > With
> > > all the stuff I have read, I have no idea how people convert the
> > > audio/graph/scales/whatever into the hex or binary that would be
> > burned
> > > onto a wavetable EPROM. Any ideas, cautions, advice, etc to drop on
> > a
> > > digital noob? I could just use the Digisound ROM, and I likely will
> > > check it out, but since I mess around with so much sound I figure I
> > > should bring some new tables.
> >
> >
> >
>
>
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