Re: A86: 86 interrupts?
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Re: A86: 86 interrupts?
Bryan Rittmeyer wrote:
> Hi again..
>
> Do any of you guys know if the link port is messed with in any
> of the interrupts? I've noticed that when you plug in a link
> cable (I.E a PC || link) the cursor will freeze for a second or
> so. Seeing as how the link port probably does not generate
> a physical insertion interrupt (there is no switch in it, I don't
> think) I'm wondering how the calculator knows a link cable has
> been inserted. What I think is happening is the ground band of the
> cable is coming in contact with the signal lines as the connector
> is inserted and the calculator times out waiting for another 7
> bits and/or an acknowledge for the one erroneous bit. However,
> in order for it to detect this bit at all there has to be something
> actively examining the TI link port when the calculator is at the
> home screen.
>
> If there is indeed a link port interupt, would it need to be disabled
> for a user assembly program that is using the link port? The E2-86
> driver is causing all sorts of random timeouts and I'm wondering if
> there isn't some interrupt I don't know about playing with the link
> port along with my driver.
>
> Thanks and regards,
>
> --
> Bryan Rittmeyer
> mailto:bryanr@flash.net
> http://www.bridges.edu/horizon/
There's no link port interrupt, it's _getkey that's doing this. I wrote
a program to see what _getkey value would be returned by the link port,
and I ended up with 6 (the same as enter, which means that it must also
set some kind of flag or something like that). Here's the program; see
if it gives you a different number (run the program and then plug in the
link while it's waiting):
wait:
call _getkey
jr z,wait
ld l,a
sub a
ld h,a
jp $4a33
References: