External Interrupts 89c51 using Keil Compiler

Hi , I want to use external interrupts of 89C51 to receive/transmit data using sync modem. Following is the C code i have written but that is not working.I'm using evaluation version of Keil Compiler...
External Interrupts 89c51 using Keil Compiler

Hi , I want to use external interrupts of 89C51 to receive/transmit data using sync modem. Following is the C code i have written but that is not working.I'm using evaluation version of Keil Compiler...
ISR (INTERRUPT SERVICE ROTUINE )... PROBLEM WITH 89C51

above give attachment ... is of multisim 11 file..in that.......when we execute program of mcu ...1st cycle works properly... when we disable interrupt it and use that pin as i/p pin key...and by pressing...
ISR (INTERRUPT SERVICE ROTUINE )... PROBLEM WITH 89C51

above give attachment ... is of multisim 11 file..in that.......when we execute program of mcu ...1st cycle works properly... when we disable interrupt it and use that pin as i/p pin key...and by pressing...
Interrupt handling for 89C51

In the manual , example code written intrrupt is : void example(void) interrupt 1 using 2 { ..... ..... } Can someone tell me what is meant by " using 2" there? thanks