🚀 go-pugleaf

Hi, folks:

I wrote a DOS program in Borland C++, because my interrupt service routine
block OS for 3 millisecond of every 5 millisecond, I think this cause 
bios no time to serve and check keyboard buffer, which cause keybord buffer
overflow.

Two questions:
1. related to process of bios handler keyboard buffer, when IRQ1 generate 
a interrupt, but has not finished its ISR, can other IRQ, such as IRQ7 
generate a interrupt in between ? How can keyboard buffer overflow happen ?

2. cli and sti will disable and enable all IRQ, is there a instruction which
will only disable and enable one specific IRQ, like IRQ7.

structure of my program

int main(void)
{
 	InstallExternalTimingIRQ7ISR()

        while( waitkey() )
	{
		doKeyboardInput_ScrOutout();
	}
        
        ReinstallOldIRQ7ISR();
}
My interrupt happens every 5 ms and program need 3 ms to finish its ISR,
during this time, I use cli and sti to protect its service, how will this 
affect keyboard interrupt ? The interrupt I used is external circuit 
generate 5 ms interrupt connect to IRQ7.

Thanks folks, this is urgent for me, please send me a mail.


Bin