knudsen@ihwpt.UUCP (mike knudsen) (05/01/86)
Here is a repost of a 1-page <BNF> syntax for MIDI bytes. Very handy for writing state-machine software; nail it to wall for a cheat-sheet. Regret to say I lost the original author's name. I cleaned it up a little, shortened names and tabbed it so that: alternatives always begin with | and are flush, but continuation lines are tabbed in two spaces. Lucky I read news today before reposting the justly famous MIDI Primer by Bob Mcqueer -- two others already have. Too bad, cause I'd cleaned up and commented my copy a little, and separated the "pulpit" section from the facts. -------- begin repost of MIDI.BNF ------------------- The latest issue of the IMA bulletin had an article on BNF for MIDI. The article points out that this syntax is what can be TRANSMITTED and the actual RECEIVER implementation may differ slightly from this grammer. This may allow greater error tolerance. The example given is that of tranmitting a system exclusive message without the termination byte <eox> F7. A channel status byte could also be used to terminate a system exclusive in the event the eox byte is lost due to error or power down etc... Definitions 3-17 define running status and realtime data insertion as well as the various channel messages. 1. <MIDI Stream> ::= <MIDI msg> < MIDI Stream> 2. <MIDI msg> ::= <sys msg> | <chan msg> 3. <chan msg> ::= <chan 1byte msg> | | <chan 2byte msg> 4. <chan 1byte msg> ::= <chan stat1 byte> <data singlet> <running singlets> 5. <chan 2byte msg> ::= <chan stat2 byte> <data pair> <running pairs> 6. <chan stat1 byte> ::= <chan voice stat1 nibble> <hex nibble> 7. <chan stat2 byte> ::= <chan voice stat2 nibble> <hex nibble> 8. <chan voice stat1 nyble>::= C | D 9. <chan voice stat2 nyble>::= 8 | 9 | A | B | E 10. <hex nyble> ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | | 8 | 9 | A | B | C | D | E | F 11. <data pair> ::= <data singlet> <data singlet> 12. <data singlet> ::= <realtime byte> <data singlet> | | <data byte> 13. <running pairs> ::= <empty> | <data pair> <running pairs> 14. <running singlets> ::= <empty> | | <data singlet> <running singlets> 15. <data byte> ::= <data MSD> <hex nyble> 16. <data MSD> ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 17. <realtime byte> ::= F8 | FA | FB | FC | FE | FF 18. <sys msg> ::= <sys common msg> | | <sysex msg> | | <sys realtime msg> 19. <sys realtime msg> ::= <realtime byte> 20. <sysex msg> ::= <sysex data byte> <data singlet> <running singlets> <eox byte> 21. <sysex stat byte> ::= F0 22. <eox byte> ::= F7 23. <sys common msg> ::= <song position msg> | | <song select msg> | | <tune request> 24. <tune request> ::= F6 25. <song position msg> ::= <song position stat byte> <data pair> 26. <song select msg> ::= <song select stat byte> <data singlet> 27. <song position stat byte>::=F2 28. <song select stat byte> ::= F3 ------ end of MIDI.BNF --------