Re: A86: What is the Interrupt?
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Re: A86: What is the Interrupt?
IM 0 expects the address to jump to to be put on the data bus - since you
can't do this on 86's you'll crash.
IM 1 will jump to 38h. More on this later
IM 2 Takes the low byte of the address from the I register and expects the
high byte to be inserted on the bus. This byte (if IM is set to 2) will be
random, but you get around this by making a 257 byte table so no matter what
the bytes is you dictate where it will jump. Of course all of the table has
to equal the same byte ($8888) and that is where you store your interrupt
handler.
TI put a hook on IM 1 where if some flag is set in the RAM it will jump to
your interrupt handler's specified address before or after going to 38. Not
sure. If your going to do interrupts use this method. Its way easier.
Andres Garcia
-----Original Message-----
From: Adler <adler@digicron.com>
To: assembly-86@lists.ticalc.org <assembly-86@lists.ticalc.org>
Date: Sunday, January 25, 1998 1:43 AM
Subject: Re: A86: What is the Interrupt?
>
>you are being too technical. Could you please go more in depth?
>
>-Thanks
>
>Grant Stockly wrote:
>>
>> It is in the processor. In the 85 I think it happens 185 times every
second...
>>
>> I hope you can understand this! I tried not to get too technical...
>>
>> Grant
>>
>> >I've heard something about this interrupt, but what is it?
>> >--
>> >Buy Mac OS8
>> >http://macos.apple.com/macos8/
>> >
>> >Mail from adler@digicron.com - http://javalamp.home.ml.org/
>>
>> ---
>> Grant Stockly
>> AppleCyber - http://www.alaska.net/~gussie
>
>--
>Buy Mac OS8
>http://macos.apple.com/macos8/
>
>Mail from adler@digicron.com - http://javalamp.home.ml.org/
>