[sdiy] Looking for an ADC

[rsdio at audiobanshee.com]

Reading the Wikipedia page for Roland DCB, I do not see any resemblance to MIDI. Can you explain any way that they're similar, other than being 8-bit codes for keyboards? I'd be curious to see some details.

I was browsing the MIDI.org site recently, where they mentioned that the first proposal for MIDI was published at an AES convention. As an AES member, I was able to find the paper, and I must admit that I was surprised. The original MIDI proposal was a very different protocol from what we have today. It was more like other 8-bit protocols of the day.

However, modern MIDI has much more in common with the short-lived original proposal than anything I see in DCB.

My viewpoint may be skewed (jaded?) because I've seen so many 8-bit protocols over the decades, and have invented several of my own for commercial products for clients. When there is a communication need, it's not too difficult to invent a protocol, especially if you don't need it to last for very long or be compatible with more than a handful of products. Surprisingly, modern processors are still often limited to 8-bit serial links, even though a few processors can handle 24-bit and 32-bit serial protocols. In other words, I think you're giving far too much credit to Roland for DCB.

However, I do have a strong suspicion that the differences between the first MIDI proposal and the final 1.0 spec were due to the input of companies like Roland. Not that DCB was spliced onto MIDI 1.0, but that MIDI 1.0 was more like what Roland wished they had done, and was a result of several manufacturers learning curve from their own proprietary protocols.

Brian


On Apr 27, 2017, at 9:10 AM, MTG <grant at musictechnologiesgroup.com> wrote:
> I wonder if this wasn't them actually using the Roland DCB data format. Near as I can tell the MIDI protocol borrows heavily from the DCB one. Splitting hairs, but in my humble opinion I think not enough credit goes to DCB as the father of MIDI. Anyway, same issue with not enough bits.
> 
> On 4/27/2017 6:34 AM, Tony Kalomiris wrote:
>> Elaine, if you are going to digitize voltages (control pots etc.) with it , have a look at the Jupiter-6, for example,  for ideas. (ADC0803).
>> It only uses 7 of the 8-bits however in software due to that Roland serial transmission scheme they adopted that uses MIDI baud rates to talk to the voice boards.
>> Ah zipper noise knob-twiddling.