Re: A82: Crashes!!!!!

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Re: A82: Crashes!!!!!

> PROTECTED MODE?!?!?  You have no idea what you are talking about.
> Protected mode puts the CPU, on a PC, into 32 bit-full RAM access mode.  It
> doesn't "protect" RAM like you may think it should  (in fact, crashes are
> frequent if the programming team had no idea what they were doing).

Actually, I do know what I'm talking about.  Yes, I was being sarcastic about
TI using 286's.  They consume too much power, produce too much heat, etc., to
be feasible for a hand held calculator.  However, you are the one who is
wrong about protected mode.  The protected mode you are talking about is 386
class processors and above.  The 286 processor had protected mode.  However,
it was NOT a 32 bit processor.

> What I mean by full RAM access mode is that ALL RAM (every meg) is
"changed" > into one continuous block of memory.

> There are several other things that make protected mode special, but there
is NO 
> part of it that protects RAM.  EVERY program ever made has a high
probability     > that it has some flaw that could cause the PC to crash.
 EVEN protected mode     > programs can mess up RAM and cause the computer to
hang.

Protected mode makes the memory flat like you said.  But the other main
purpose of protected mode is to provide hardware support for multitasking.
 It does this by "protecting" all memory that is not available to the current
process.  Hence the name Protected Mode.  That is why a program that crashes
under a multitasking system such as Windows doesn't crash the entire system
(ok, under Win 3.1 alot and sometimes under 95, the whole thing crashed, but
that's because Windows is not entirely bug proof...what MS product is?).
 That's why you get those General Protection Faults (GPF) errors.  That means
that a program running under a protected mode operating system (Windows,
DOS4GW, GO32) has tried to access memory that it is not entitled to and has
been shut down.  (Want to test you "bug free" 16 bit programs?  Compile them
under a 32 bit compiler and watch them crash when you use a bad pointer, or
write past the end of an array.  In 16 bit mode, they crashed the computer.
 In 32 bit mode, they are politely shut down by your OS.)  Yes, a protected
mode program can crash the system (overwriting it's own code), but not by
accessing other program's or the operating system's memory.

Sorry, this is WAY off subject, but I thought everyone might want to know the
correct information on this stuff.


David Phillips