we have made an OS which is runnning on pentium 1 ,pnetium2
but not on 3 4 ..it just hangs after displaying command prompt
its a text mode OS, cooperative multitasking,pmode
we have enabled by AT keyboard..
wat can be the problem?
platform problem
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carbonBased
RE:platform problem
You mean you've enabled the A20 by means of the PS/2 keyboard controller, I'm sure... and pmode by means of CR0, correct?
Can you narrow down, exactly, what code causes the OS to hang?
What does the OS do after displaying the command prompt?
I can't think of anything, offhand, that is so different on the P3+ that would break an OS, if coded properly. Afterall, Win95 still runs on P3+
I would tend to lean towards the theory that something in your OS is not coded 100% properly, but the P1 + P2 accept it, and continue about, while the P3+ actually takes offense to it, and hangs.
Perhaps this is the point where your OS first accepts keyboard input, and your A20 code has changed the keyboard's status such that it doesn't appear to accept keystrokes?
Sorry... I can't think of anything else... hopefully with some more info we can find something!
Cheers,
Jeff
Can you narrow down, exactly, what code causes the OS to hang?
What does the OS do after displaying the command prompt?
I can't think of anything, offhand, that is so different on the P3+ that would break an OS, if coded properly. Afterall, Win95 still runs on P3+
I would tend to lean towards the theory that something in your OS is not coded 100% properly, but the P1 + P2 accept it, and continue about, while the P3+ actually takes offense to it, and hangs.
Perhaps this is the point where your OS first accepts keyboard input, and your A20 code has changed the keyboard's status such that it doesn't appear to accept keystrokes?
Sorry... I can't think of anything else... hopefully with some more info we can find something!
Cheers,
Jeff
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danish
RE:platform problem
thnx 4 replying
no i mean we enabled A20 by AT keyboard controller
and yes pmode by cr0
os do nothing it just dispalys the promp and hangs but only on p3 and p4 it works fine p1 and p2
wot u think can a20 enabling be the problem coz p3 and p4 have ps/2 keyboard controller
no i mean we enabled A20 by AT keyboard controller
and yes pmode by cr0
os do nothing it just dispalys the promp and hangs but only on p3 and p4 it works fine p1 and p2
wot u think can a20 enabling be the problem coz p3 and p4 have ps/2 keyboard controller
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carbonBased
RE:platform problem
That was just a guess... they both use the same controller to enable the A20 line. I thought, perhaps, that the A20 code might be at fault. A20 code isn't always as simple as it seems. What works on one system may sometimes fail on another... whether this could be a problem for your system or not, I don't know, obviously, because I don't know how your system operates.
Do you have exception handlers defined? It seems strange that the system just "hangs"... pmode never just hangs... it faults, and you'll end up in an exception handler. If you haven't defined these handlers, perhaps you should consider doing so... they might give you a better idea of what's going on.
Cheers,
Jeff
Do you have exception handlers defined? It seems strange that the system just "hangs"... pmode never just hangs... it faults, and you'll end up in an exception handler. If you haven't defined these handlers, perhaps you should consider doing so... they might give you a better idea of what's going on.
Cheers,
Jeff
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Ramanan
RE:platform problem
May b the timer problem.
Try checking the scheduler routine and timer interrupt routine.
This may solve the problem.
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YogaRamanan.T
Try checking the scheduler routine and timer interrupt routine.
This may solve the problem.
...
YogaRamanan.T