OSDev.org

After taking almost 4 weeks to get into protected mode i got ver annoyed with the fact real mode still existed to have to get out of. I feel that a prossecor shoudl start up in a 32bit protected mode and then wait for you to set the GDT's.

I agree, however I think that if a processor is going to start up in 32Bit PMode then it should also start with code and data segments defined to cover the entire address space and then the boot code can set the environment up to its own liking.

And if they were going to break compatibility with previous models then they should also fix the need to remap the IRQ's. There are probably some other things that could be thought through like the A20 line for a start, this should be enabled automatically.

I cant see any of the hardware companies giving us what we want though. Not to this degree anyway.

Yeah the A20 line that is another of my big big gripes. I mean hands up anyone who hasn't got it enabled. Thought so.


Peter

Real mode can't leave!!! The idea is to have backwards compatiblility on a IBM computer!

I like real mode too, even though it's outdated.

I agree to that, Real Mode must be kept, however you should not have to work to get into the most desired and modern mode, it should be the other way around.

You said yourself, Real Mode is outdated, is should be secondary in the system not primary.

Just my opinion.

Regarding 'backwards compatibility':
"I usually suggest that if the word 'compatibility' is eliminated from this phrase, its true meaning becomes apparent."
- from The Humane Interface by Jef Raskin

The Working to get into real mode sounds like a good idea but then the processor wouldn't be backward compaltible as you would need stubs on each 16bit program to get the processor into real mode and would negate the whole point of backwards compatibility so you might as well scrap it all together a better bet would be to have emulation for real mode programs since on modern 32bit processors or even 64 you are not going to see real mode run slowly.