Re: A86: TI-86 interrupts, Part 2
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Re: A86: TI-86 interrupts, Part 2
Getkey will execute a 'halt' instruction to go into
low power mode, as interrupts occur the keyboard
is polled for a key press and if a key is pressed
it is read. If interrupts are disabled then nothing can
cause the halt instruction to return to getkey and you
will be locked up.
Later,
Pat
------------------
Original text
From: Bryan Rittmeyer <bryanr@flash.net>, on 7/10/98 5:36 PM:
Joshua Grams wrote:
> But wait a minute, we agreed there's no NMI, so if you shut off interrupts
> and don't call any ROM routines, how does _getkey get called? That doesn't
> seem possible to me. You can't have anything running in the background
> without interrupts (unless it gets called from most ROM routines, or
> something). Disabling the interrupts wouldn't "disable" _getkey, but it
> shouldn't get called unless you call it.
As far as I understand it, doing a di turns off the interrupt that
updates
the memory location that _getkey (the ROM call) reads. I think in the
future a discussion like this one would be more understandable if we
differentiated between interrupts and the ROM call more clearly.
--
Bryan Rittmeyer
mailto:bryanr@flash.net
http://www.flash.net/~bryanr/
References: