[sdiy] Holtek HT36A4 8-Bit Music Synthesizer‏‏

Eric Brombaugh ebrombaugh at earthlink.net
Fri Feb 29 16:49:06 CET 2008

Jim Thompson wrote:
> Hey Group,
>  Sorry I missed the Holtek thread but I was hoping somebody could please take a look at the info and datasheet links below for their Music I.C. It appears to have some nice musical functions and they say it is 8 note polyphonic.
>  I have a supply of them if anybody thinks that they would be functional for SYNTH use, please let us know or contact me off list. I would be happy to provide them to any curious individuals with programming skills as I have none. (But I can solder circles around most software engineers.) 8P
> http://www.holtek.com.tw/english/docum/consumer/36a4.htm
> http://www.holtek.com.tw/pdf/consumer/36a4v110.pdf

Interesting. Glancing over the datasheet it looks like a typical low-end 
8-bit MCU, comparable to your average 16-series PIC. The standout 
feature is the 16-bit DAC they've put on it.

I notice that nowhere in the datasheet or on the website is there any 
information about programming it. Since they specifically call out ROM 
storage, that suggests it's a mask-programmed device that can only be 
configured at the factory during fabrication. That's a bit problematic 
for the average hobbyist.

If you've got a bunch of them, perhaps they're pre-programmed with some 
sort of synthesis code. Any idea what it does? Details about that would 
be helpful to determine if this is usable.


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