New answers tagged x86
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How can a 32-bit x86 CPU start with reset vector 0xFFFFFFF0 even though it starts in 16-bit real mode?
I'm putting this in as a separate answer since some people might disagree with my logic and it will give them a chance to downvote me.
If you're interested and have the time, I think you'll find https:...
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Accepted
How can a 32-bit x86 CPU start with reset vector 0xFFFFFFF0 even though it starts in 16-bit real mode?
When x86 boots, it's not strictly in classic real mode, it's in "unreal" mode, with CS.base = 0xFFFF0000 and CS.limit = 64K.
On 286 and later, memory addressing doesn't use the segment ...
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8
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How can a 32-bit x86 CPU start with reset vector 0xFFFFFFF0 even though it starts in 16-bit real mode?
In short, yes the 386 will boot from 0xFFFFFFF0 address mentioned in real mode, because CS selector base is set to 0xFFFF0000 and IP will be 0x0000FFF0. The value of the CS register itself is ...
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How can a 32-bit x86 CPU start with reset vector 0xFFFFFFF0 even though it starts in 16-bit real mode?
To understand this, you need to understand the basics of segment:offset addressing in protected mode: the segment value points to a descriptor, which contains a base address, segment limit and various ...
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Are there any statistics or data showing how much more productive the C programming language is compared to x86 assembly language?
There's not single answer here because you have a number of compromises involved.
Calling Conventions
For example, in assembly language you get (roughly) three choices about how to pass parameters to ...
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Is it possible to detect a CGA card on an IBM PC 5150 by write/reading the Motorola 6845?
To answer the specific question:
What happens if you write to an I/O-port that doesn't exist in the hardware? Does it crash?
That doesn't happen with any Intel or Zilog microprocessor I'm aware of. ...
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Are there any statistics or data showing how much more productive the C programming language is compared to x86 assembly language?
Yes, there probably have been studies, but they are almost certainly in paywalled journals. You can find some links if you go to scholar.google.com and search for something like "programmer ...
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Are there any statistics or data showing how much more productive the C programming language is compared to x86 assembly language?
You'll never find a good single number for this sort of thing.
One factor is that software time estimation is famously difficult in-general. Nobody has ever been good at estimating how long software ...
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Are there any statistics or data showing how much more productive the C programming language is compared to x86 assembly language?
TL;DR The productivity gain is in the portability of the "C" language relative to Assembly.
I think you might have an unintended caveat in the question in referencing a specific dialect of ...
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