Re: A86: Maskable Interrupts
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Re: A86: Maskable Interrupts
On Sun, 3 Jan 1999 04:56:48 -0700 "Dux Gregis" <assets@eden.rutgers.edu>
writes:
>
>
>>
>>isn't this the off routine?
>>¦0c4c d303 out (#03),a ;turn off screen
>
>out 3 should turn off the LCD but also enable both the interrupts (bit
>1)
>and the on interrupt (bit 0?)
i didn't know that. the instruction before that is ld a,$01.
>that's really weird that the interrupts don't run .. it looks as
>though they
>should
>what is that exchanging for?
i don't know, but the interrupt routine starts with that, maybe there's a
connection?
-josh
>>it seems to me that the calculator is always "off". in normal
>operation,
>>(when it's not busy) it sits in a halt loop, waiting for an interrupt
>to
>>tell it to blink the cursor or register a key. when you turn it off,
>it
>>shuts down the screen and possibly disables the "200/sec" interrupt
>>signal from whatever generates it. this is mostly speculation, but
>it
>>makes sense.
>
>from this I am guessing that the calc actually does run interrupts
>while it's off
>first because it's setting the bit to enable the interrupt and also
>using ei second because a loop would be useless otherwise
>third, where else would it break out of this seemingly infite loop
>from?
>
>we could find out for sure if we knew what that exchange stuff was for
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