[sdiy] Wavetable fat chance...

[harrybissell]

Does anyone have any EPROM images for the
360 Systems Pro Midi Bass ???

(other than the factory installed ROMs) ???

shot in the dark eh ???

H^) harry

Grant Richter wrote:

> on 12/31/03 2:46 PM, Tom Arnold at xyzzy at sysabend.org wrote:
>
> > Can anyone point me at a description of the ROM formats common for things
> > like the ProphetVS and the like?  I guess all I really need to know is the
> > common sample size used, but if there's any compression that'd be
> > interesting to know about also.
> >
> > Thanks.
>
> The Digisound VCDO used a 64 byte / 8 bit sample. Storing 32 waves in a 2K
> EPROM. For the sake of simplicity, this corresponds to a sample time of 5.8
> mS at a sample rate of 11 kHz.
>
> Most common is a 128 byte / 8 bit sample. This was used by the Prophet VS
> and Wave PPG instruments. Compression consists of storing 64 bytes of a
> symetric wave (1,2,3...3,2,1). For the sake of simplicity, this corresponds
> to a sample time of 5.8 mS at a sample rate of 22.05 kHz.
>
> The Mini-Wave, Waveform City, Doepfer A-112 sample playback module use a
> straight uncompressed 256 byte / 8 bit sample. For the sake of simplicity,
> this corresponds to a sample time of 5.8 mS at a sample rate of 44.1 kHz.
>
> Resampling the waveforms is not recommended as most of the character is from
> aliasing. For example, if you get a waveform image from a VS or PPG EPROM,
> you can write a simple QBASIC program to uncompress them and store two
> copies to make a 256 byte wave. This will preserve the original "buzziness".
> Resampling via Sound Forge mellows them out a lot.
>
> I've got the JD-800 waveform ROM bit images, but no clue as to how to read
> them. Not straight PCM, that's for sure.
>
> 256 byte Wavetable editor & librarian is at:
>
> http://www.wiard.com/support/support.html
>
> under "Software".