hmmm... real mode question

[rdragon]

Hmm... Ive been thinking... Why is so much emphasis put on hobbyist programmers to program protected mode OS's... I mean, DOS is a real mode only OS, isnt it? It seems like real mode has a much simpler design concept, since only "one" thing can be running at a time. I was thinking of trying to start doing an OS, but doing it in real mode. Is it that much different/harder? I know most everything will be 16-bit, but thats okay... ?

[Pype.Clicker]

real mode is outdated, and give you access only to 1MB of memory ...

Stuffes like networking or GUI dezign becomes tricky as hell without multiprocessing ... Did you only tried to have a background CD player in DOS ? this requires a terminate-and-stay-resident approach, hook transparently the keyboard or mouse functions so that you can invoke it ...

Nah, definitely, if you had tried complex program in realmode, you would receive protected mode as a gift from gods...

[rdragon]

is real mode easier to code the OS in though? i dont plan on this becoming very popular or anything, as most things ;p

[Tim]

No, because you're constantly coming up against segmentation and the limitations it introduces.

Have you done much real mode programming before?

[rdragon]

no, i cant say i have done any at all really, except my qbasic days in dos, heh

[jrfritz]

Well then...PM has a whole bunch of stuff for you to have multitasking space, organise you OS in memory and more and more and more....

Tell me, then...how are you going to make multitasking in your OS?

[Pype.Clicker]

no, i cant say i have done any at all really, except my qbasic days in dos, heh

Then i suggest you choose protected mode. And if entering pmode scares you (and yes, you're rightfully afraid : it's quite a hard task , just let another open-source programe (Grub / Fritzos / SOS / whatever.) do the job for you and then take over it

The only thing you might not wish about a pmode OS is the lack of BIOS support (no INT 10 or INT 13 anymore ...)