Re: A86: Maskable Interrupts
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Re: A86: Maskable Interrupts
isn't this the off routine?
¦0c4c d303 out (#03),a ;turn off screen
¦0c4e fdcb129e res 3,(iy+#12) ;shift2nd
¦0c52 fdcb099e res 3,(iy+#09) ;onRunning
¦0c56 08 ex af,af'
¦0c57 d9 exx
¦0c58 fb ei
¦0c59 76 halt
¦0c5a 18fd jr #0c59 ; (-3)
what is that if not a loop?
if interrupts are shut off, they are shut off with external circuitry,
not with di. there is no place in the rom where di is followed by a halt
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.
-josh
On Sat, 2 Jan 1999 02:22:01 -0700 "Dux Gregis" <assets@eden.rutgers.edu>
writes:
>
>
>>
>>> no, it's not in a loop. halt waits for an interrupt ... when the
>calc is
>>> turned off so are the interrupts _except_ for the on key interrupt,
>which
>>> ends the halt when it is triggered.
>>
>>I'll look that up and get back to you.
>
>you _can_ believe me. I've looked at the code :-)
>
>
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