Gregory,

The '2051 is suitable platform for midi message handling. A couple comments.

1) Your timer value is correct for 31250 bps. you might consider placing this value in TL1 at init time as well just to avoid sending a 1 time corrupt serial value.

2) You should "remote" the state of TI to a bit flag. Your interrupt service routine can "jbc TI" to where you set this bit flag and then proceed to test the RI state. Of course your Tx Serial routine would now test this new bit flag instead of TI directly.

3) Looks like you can avoid push/popping PSW/ACC by modifying your ISR to "mov @r0,sbuf".

I have written MIDI xfaces for '2051, DS420 and MSC1211 if you want examples let me know.

regards,
p