Hi

I'm programming under DOS 6.2. I want to switch the polarity of the interrupt source 5 from "high active" to "low active" so an IRQ appears on a negative edge instead of a positive edge (or level, in my case it's edge).
Does anybody know how to do this in a correct way?
I've seen that there is an APIC controller (connected as PCI-device), but I don't know if this APIC is active under DOS(I don't think so) and I'm not able to address this PCI device because I didn't figure out if it's possible to create 32 bit pointers in a DOS application. Can anybody help me?

thanks

>>I didn't figure out if it's possible to create 32 bit pointers in a DOS application
Yes, it is possible, depending on the memory model. use the FAR keyword to create 32-bit pointers in small memory model. 32-bit pointers are default in the large memory model. But that still can't address memory above the 1 meg limit.

Why would you even want to mess around with dos anyway? A 32 bit OS runs on almost anything nowadays. I mean, even your telephone probably runs on something like WinCE or Solaris

Why would you even want to mess around with dos anyway? A 32 bit OS runs on almost anything nowadays. I mean, even your telephone probably runs on something like WinCE or Solaris

You're right, but its important that the OS is starting up as fast as possible, so DOS is a quiet good alternative. And under DOS, there were code fragments available, so...

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