[sdiy] MIDI specifications

[Gene Stopp]

>Oooo.... he said "link layer"... so there's
>still people out there that believes in the
>ISO OSI layering crap? (The OSI layering
>caused more headache than it solved, the
>OSI degeneration with the IP world leaves
>even more to be desired.)

OSI-speak is a hard habit to break! Especially with so many mixed-opinion
co-workers. But one look at a detailed OSI-model layer chart will tell you
that something went wrong somewhere!

>Also, you where incorrect on another thing,
>in RS-232 you actually have threelevels, and
>if you don't understand this you won't easilly
>grip why turned of equipment causes other
>equipment to malfunction. 0V is the "break"
>level, having a totally distinct meaning from
>that of logical high and logical low. In MIDI
>there is fortunatly only two levels. However,
>three-level signals make the world tick (PDH
>tends to use it, besides all those RS-232
>stuff).

Arrgh - I forgot about Break! The <ctrl><alt><del> of the RS-232 world!
Notice that there is still a Break key lingering on your PC keyboard, up by
the Scroll Lock key. Kind of like the way we still call Enter "Carriage
Return".

Yes MIDI is free from many of these worries, it does what it needs to with
minimum hassle and some shorcomings. If I said that MIDI channel messages
are "data plane" and MIDI system messages are "control plane", would you get
mad at me? :)

- Gene