[LAU] Roland A500S: snd-usb-audio error -5

[Ralf Mardorf]

On Sun, 29 Jan 2017 09:14:07 +0100, Ralf Mardorf wrote:
>On Sat, 28 Jan 2017 17:55:40 -1000, david wrote:
>>So I wonder. Is there some sort of upper speed limit in the MIDI 
>>standard? Is the MIDI standard smart enough to negotiate speeds if 
>>various MIDI devices differ? Or was the MIDI standard strict in
>>saying that your device must operate at this official speed?  
>
>You are aware that MIDI data simply is send and received without a time
>stamp and without any sync. The software checks if an ACIA/UART
           ^^^^^^^^^^^^^^^^ English isn't my native language, this
           phrase might not be that good, but it anyway is to the point.

>register reports that a byte was received by a short machine language
>endless loop. The endless loop is only interrupted by a branch, if a
>byte was received, to read the byte and then to continue the endless
>loop. On old computers such as the C64 a lot of MIDI operations were
>done by even disabling IRQs. The 65xx chips have a command to disable
>timer and break command/flag IRQs, named SEI. One MIDI interface must
>use the same rate on both ends, the receiver and transmitter, but if
>you use different interfaces you could ignore the MIDI standard and
>chose any other rate, as long as sender and receiver chose the same
>rate. IOW one interface could not communicate with several MIDI
>interfaces using different rates.