Real mode interrupt table address

[Red Shaya]

Hello,
I'm still at my real mode stages and I'm now starting (trying to) to develop my first ISR.

My question is where does the interrupt table reside in real mode.
The documentation I've read so far deal with IDT's which is nice if you are coding for PM.

(Also, a pointer to a document that explains the memory layout after the POST process is finished would be great).

TIA

Shaya

[AR]

Map of low memory in the Wiki

The IVT starts at 0000:0000, each 4 bytes represents a CS:IP pair (IIRC) for the interrupt. If you're using the IVT then I think the recommended approach is to read the existing value, replace it with yours then rememeber to far call to the one you read afterwards

[Red Shaya]

Thanks for the quick reply.

I guess my IVT is going to suffer lots of abuse, when i come back home this evening, until i get it working right

[Dex4u]

Here is some asm code that may help, it for making your own ISR in realmode, from a OS dev point of view.

Dex4u.