MIDI

jdow jdow at earthlink.net
Sun Nov 12 02:54:48 UTC 2006


From: "Gene Heskett" <gene.heskett at verizon.net>
> On Saturday 11 November 2006 21:00, Tony Nelson wrote:
>>At 4:21 PM -0500 11/11/06, Gene Heskett wrote:
>> ...
>>
> This thread might be of interest to the linux-audio-dev group, so I've 
> added them to the Cc:
> 
>>>Yup, and its been a constant src of amazement to this old fart that
>>> when the midi spec was setup, they used a serial port, thats fine, but
>>> when they set the data rate at only 31,250 baud, ...
>>>
>>>Consistently attrocious timeing, with the horns always 1/16 beat late
>>>unless the actual output order of each instrument is scrambled in the
>>>order output.  That would make it sound a heck of a lot less
>>> mechanical. And there isn't a heck of a lot that can be done until we
>>> put midi on an optical circuit running at several megabytes/sec. 
>>> Something like TOS maybe?
>>
>>Firewire.  Many products already, plenty of speed, almost robust enough.
>>1/8 millisecond isoch cycle times; each cycle can contain packets from
>> many senders; each packet can contain lots of notes.
> 
> More robust IMO than the din connectors now used for midi interconnects, 
> however the cabling itself can't help but be more fragile when subjected 
> to the rigors of a jam session with bodies walking on them all night.  
> And that has to be a consideration else the first users will get 
> discouraged at the high cable failure rates and revert, particularly if 
> they have a tin ear and can't hear what to many of us would be an 
> extremely obvious improvement.
> 
> But I like that idea, a lot.  Maybe some enterprising LAD people could get 
> together and spec something like a midi interface running over firewire, 
> complete with the repeaters so it can be daisy-chained just like midi can 
> be, and hopefully release it into the PD as a new midi-2 interface 
> standard.  And design it such that it never, ever gets into the snails 
> trail of the 31,250 baud interface it uses today.

Runs like snails. But I have seen installations with FAR more cable on
MIDI runs than the specification suggests is the maximum. (It is off
by orders of magnitude. I suspect a conforming driver and receiver
coupled with zip cord could go a half mile and still work - with
normal timing. I can't do that with Ethernet. Can't do it with
1394 or USB, either. MIDI physical transport layer is indeed slow.
It is staggeringly robust.)

{^_^}




More information about the users mailing list