ric@hpspdra.HP.COM (Ric Peregrino) (03/12/91)
Concerning MIDI sample data dumps: I have an A2000 1.3 with a program to send and receive MIDI sample data dumps. It's not pretty, but I'd like to make it so. The ugliness is that I Disable/Enable around a RBF (TBE for send) polling loop, thus taking over the machine. What I would like to do is have a RBF interupt service routine that **DOESN'T MISS A BYTE**. Sending is not a problem. The problem is MIDI 31250 BAUD; 8bits, 1 start, 1 stop; 320uS/data. So I've got to get the data and be ready for the next data in 320uS. The question I pose is how long (in CPU clock cycles) does it take from a RBF interupt to when my service routine gets control of CPU, in the worst case (I guess you need the operating system source code to answer this). I noticed the hardware priority for the RBF is 6; can any other interupt override this? If so, all hope is lost. ric@hpspd