Real mode interrupt vectors

Michael Still mikal at
Thu Apr 3 08:14:30 EST 2003


in furtherance to my turnipism from yesterday, I am now having trouble
installing a real mode interrupt handler. My code is something along the
lines of:

bad_op_mess:	.string	"Hey, try the right CPU, turnip!"

bad_opcode:	lea	bad_op_mess, %si
		call	prtstr

(All of which I believe works. prtstr is a method which prints out a
string to the screen)

Now I want to install the interrupt handler. I'm after interrupt 6, so I

		lea	bad_opcode, %si
		mov	%si, 0x1A
		mov	%cs, 0x18

This bit doesn't seem to work. My understanding that interrupt 6 should
occupy bytes 24 - 27 in the ineterrupt vector, which is at the start of
memory. Obviously I am wrong.

There doesn't seem to be much doco out there for real mode, it's all for
protected mode. Does anyone want to give me a hint?



Michael Still (mikal at | Stage 1: Steal underpants            | Stage 2: ????
UTC + 10                          | Stage 3: Profit

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