Re: What's wrong with this little TSR?

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#708

From: Horst Kraemer
Date: Tue, 25 Aug 1998 00:00

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On Tue, 25 Aug 1998 18:39:59 +0200, Michael Knapp
<michaelknapp@nol.at> wrote:

>> >         asm       { Enable INTERRUPTS again         }
>> >         sti;
>> >         popf;

>> ---> ???? popped the cleared I-flag here!

>POPF has *NO* effect on the I-flag !!!

Of course POPF will pop the I-flag.

Try this program under plain DOS.

begin
  asm  cli ; pushf ; sti ; popf ; hlt end;
  writeln('hi, I am back');
end;

'hlt' will stop the processor until the next hardware interrupt
occurs.

{
This program

     begin
       asm sti; hlt end
     end;

will end immediately because the timer interrupt is "waking up" the
hlt instruction.
}

If your program ends normally, you are correct.

If you have to reboot the machine, I am correct.

Regards
Horst

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From: horst.kraemer@snafu.de (Horst Kraemer)
Subject: Re: What's wrong with this little TSR?
Date: 1998/08/25
Message-ID: <35e31b2f.3414235@news.snafu.de>
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References: <35ded96b.41078299@news.rz.uni-karlsruhe.de> <35E20513.EF631A2F@hotmail.com> <35E2FD32.97351F78@eunet.at> <35E2E8DF.122B31B2@nol.at>
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