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I am trying to write a floppy driver. I make the IRQ6 hanlde which sets variable a true. And the RTC timer to turn off the floppy motor.

But when i enable de RTC, irq 28, it not works. I use my enable IRQ function ( with irq 0 1 6 works... )

My question is: this enable IRQ will not work on the RTC? do i need any other function to enable RTC?


Thanks.

hello

there are only 15 irqs, maybe that's the error?

there is a timer at irq 0.

You shouldn't need to use the RTC for this (and if you did, you'd have to set it up properly). The PIT on IRQ 0 will be enough for a floppy motor timeout.

Adrian wrote: there are only 15 irqs

Don't you mean that there are only 15 hardware interrupts, that is, external to the CPU. Because there are up to 31 exceptions inside the CPU (although 15, 19-31 are reserved). But can't you have up to 255 interrupts in your IDT? Albeit, software interrupts.

Or have I misunderstood?

IRQ stands for Interrupt ReQuest, and refers to hardware interrupts sent by the Programmable Interrupt Controller. IRQ0 is timer (mapped to INT 8 in realmode), etc

well ok,

I will use timer in irq0. I've re-mapped it on irq 0x20.

But now what about RTC? isn't it on the irq0 in the slave pic? so it should be at irq 0x28,that's it? ( it's only a curiusity )