Thanks p, it still not working.

Here is situation:
source is

void Serial_Init (void)
{
SCON = 0x50; // SCON: mode 1, 8-bit UART, enable rcvr
TMOD |= 0x21; // TMOD: timer 1, mode 2, 8-bit reload
TH1 = 0xff; // MIDI baud rate for 12.000 clock
TL1 = 0xff;

PT1=0; // as you proposed
ET1=0;

PCON &= 0x7f; // SMOD=0
TR1 = 1; // TR1: timer 1 run
TI = 1; // TI: set TI to send first char of UART

ES=1;
EA=1;
}

from interrupt routine i send last received byte to P2 and i use osciloscope to veryfy last received byte.
I use midiOX to send messages from PC to uC, last byte is velocity byte of midi message and i exacrly know the sent value but received value is never the same.


void serial_IT(void) interrupt 4
{
RI=0;
P2=SBUF;
}

Do i have to refresh TH1 and TL1 from interrupt routine every thime timer 1 overflows?

Thanks to anybody that answers!!