Re: TI Graph Link Errors

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Re: TI Graph Link Errors

At 02:29 PM 7/31/96 -0700, you wrote:
>Eric P. Anderson wrote:
>
>
>> Actually, it seems you have been educated.  This information supports MY
>> original argument.  Here, I'll even show you your incorrect statement.
>>
>> >1)  Yes IRQs are hardware related.  How the software handles them is OS
>>
>> >related.  That is called IRQ handling. Certain OS's can handle multiple
>>                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> >devices on the same IRQ at the same time.  Others (DOS based) can't.
>>  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>
>> I eagerly wait to see how you respond to this.
>
>>  Besides, doesn't it sound logical for just one device to use an IRQ
>>anyway?
>
>That last line is my favorite!!  What a gem.  You simply don't get it, do
>you?
>
>
>Again, it falls to me to point out your wrongness.  The OS is the IRQ
>handler.  That is a fact.  The IRQs themselves are hardware related.
>Fact.  Gee whiz, I'm not wrong yet.  Certain Os's can handle multiple
>devices on the same IRQ at the same time.


Incorrect.  I have already shown part of the Linux FAQ (which is the newest
version, BTW) in order to shoot this down.  You apparently ignored it.


>Hmmmm...in OS/2, for example,
>I have one IRQ for my sound card.  When I open Windoze in OS/2, the sound
>card can be utilized by the windows environment. If I shell back out to
>OS/2, my sound card still works, WITH windows also in place and using it.
> Therefor, both an OS/2 program and a windows program can use the same
>IRQ for the sound card.


Yeah, but it's still the same device.  In other words, one device on one
IRQ.  It is not supposed to work otherwise.  And since you're so stuck on
this "os/2 can use multiple devices on one IRQ" here's some more to shoot
that down.


------------------------------taken from the OS/2
FAQ----------------------------------


 Configuring PC Devices


<snip an unimportant section>


More precisely, if your PC is using any AT bus or VESA Localbus adapters, you
must be extremely careful to configure these cards properly so that no system
resources (including IRQs) are used by more than one device.  Unfortunately
so-called Plug and Play (for AT bus) will not be the answer to configuration
problems, since any AT bus adapter which does not support the Plug and Play
specification (very few do today) can (and often will) come into conflict with
other devices, and even a Plug and Play PC probably will not be able to
determine what resources that "old" card is using.  In short, be careful.


<snip another portion>


o Interrupts (IRQs).  When an event occurs which your PC needs to respond to
(such as clicking a mouse button), a signal (called an interrupt) is sent to
your PC's processor by the interrupt controller.  The interrupt controllers
(there are two) are responsible for monitoring sixteen IRQ lines, numbered 0
to 15.  The first controller responds to IRQs 0 to 7. The second controller
handles 8 to 15.  Only the first controller is actually allowed to "talk" to
your computer's processor.  If the second controller receives an interrupt
(for example, as a result of a network card signalling incoming information),
it signals this event to the first controller by triggering IRQ number 2 and
passing the true IRQ number (8 to 15) to the first controller.


<snip a portion that's not important>


No devices in your PC should ever share IRQs.


-------------------------------------end FAQ
portion-----------------------------------




>Still with me?  This is called IRQ handling.  It
>allows the CPU to decide the priority of the IRQ usage, similar to a
>street light controls traffic.  Try this in dos with a mouse on one com
>and a calc link (that is what this is all about, remember?) on another
>com, both with the same IRQ, and the OS will default to either one device
>(mouse or calc link) getting sole usage of the IRQ, or it will freeze up
>the IRQ entirely, locking up both.  Therefor, Dos is a certain OS that
>can't handle multiple devices sharing an IRQ.  OS/2 is a certain OS that
>can handle multiple devices sharing an IRQ.  Hmmmm...looks like I wasn't
>wrong there, either.  Remind me again, exactly what was I said in the
>enclosed text that was wrong?  And please do some more reading up on
>this, I tire of you embarassing yourself and explaining the same
>childishly simple concepts to you over and over again.


In order to be able to share an IRQ, the hardware would have to be able to
support this.  Sharing of IRQs by more than one device is not possible due
to hardware design.  You could put OS/2 Warp Version 100 on it and you
aren't going to be able to share your IRQs.  If you would have learned basic
hardware facts about the PC in the first place I wouldn't have had to
explain this to you three or four times.  Any questions?


>Please peddle your butt on home to Mama, and consider this my last
>missive.  All future mail from you will be deleted upon receipt.


Fine.  Do what you will.  It doesn't change the facts.
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