Linked by Thom Holwerda on Sat 9th Feb 2013 18:54 UTC
Windows "The 16-bit Windows kernel was actually three kernels. One if you were using an 8086 processor, another if you were using an 80286 processor, and a third if you were using an 80386 processor. The 8086 kernel was a completely separate beast, but the 80286 and 80386 kernels shared a lot of code in common." As always, Raymond Chen delivers. If you don't yet follow his blog, you should. Right now. Click that bookmark or RSS button.
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Megol
Member since:
2011-04-11

moondevil,

"You got it wrong. Let me explain as I was already a long time computer user on those days."

I actually agree with everything (else) in your post, but was anything factually wrong in mine? It's definitely possible but your response didn't make it clear what is wrong.

I find it very strange how intel failed to anticipate the need for a mode switch, but mainboard manufacturers did by implementing the external 286 reset logic. Was there an early generation of 286 mainboards which didn't support a cpu reset?


No. There could perhaps be mainboards that doesn't support the reset protocol needed but that's unlikely.
Doing the reset itself can be done in software without extra hardware by triggering a triple fault, just load the interrupt description table pointer with something faulty and then do a software interrupt.

Reply Parent Score: 2

Alfman Member since:
2011-01-28

Megol,

"Doing the reset itself can be done in software without extra hardware by triggering a triple fault, just load the interrupt description table pointer with something faulty and then do a software interrupt."

Ah, very clever! And here I was thinking it was an oversight by the bastards at intel, how wrong I was. My faith is restored ;)

Reply Parent Score: 2