[sdiy] x0x memories (TB-303, TR-606, TR-808)

[ed cope]

Check this site:
http://ultra303.ultrafex.de/
it has some info on writing a microprocessor replacement for the 303 
microprocesser

ed

Richard Wentk wrote:

> At 12:49 20/01/2005, Mattias Rickardsson wrote:
>
>> Hi,
>>
>> I have some things that I must delve deeper into, and maybe you can 
>> help me.
>>
>> The TB-303, TR-606, and TR-808 have a microprocessor (containing also 
>> the program code, I believe) and some memory ICs beside it (holding 
>> the pattern/song data, I believe).
>>
>> Is this external memory used in such a way that it could be 
>> "emulated" by some other thing connected to the same microprocessor 
>> pins?
>>
>> What I mean is basically this:
>> Does the 808 read the external memory ICs continously (like a sheet 
>> of music notes) while playing, so that an emulator could decide at 
>> any time what the next step should contain? Or is the external memory 
>> read in larger chunks, stored in the microprocessor while playing, 
>> and nothing can change it while playing?
>
>
> I'm pretty sure the drum machines are step based. But the 303's glide 
> feature would need some lookahead.
>
>> (Has anybody done some neat tricks or analyses with this x0x memory 
>> architecture?)
>
>
> What are you trying to do? If it's customised pattern 
> sequencing/creation, it might be easier to go the other way round - 
> throw out the microprocessor and the memory completely, and replace it 
> with trigger circuitry of your own design, keeping the audio circuitry 
> intact.
>
> Richard
>
>
>
>



-- 
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 265.7.0 - Release Date: 1/17/2005