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Offline Joewawaw

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Link Port help
« on: September 12, 2014, 12:45:19 pm »
Hi,
I was reading on WikiTI that when a line on the 83+ calculator link port is pulled low, the OS responds by pulling the other line low. I wanted to disable this feature somehow (is it an interrupt?) so that i could have full control over the link port.
does anyone know how to do this? Thanks
Im using an 84+SE calculator, if that's relevant.
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Offline Keoni29

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Re: Link Port help
« Reply #1 on: September 12, 2014, 01:48:14 pm »
It is generally a good idea to turn off interrupts. Makes life so much easier.
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Offline Hooloovoo

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Re: Link Port help
« Reply #2 on: September 12, 2014, 11:46:09 pm »
If you are working with the link port, you will want to make sure that whenever any of the lines are pulled low, you disable interrupts with di, and when you are done, re-enabling them with ei. Be warned that certain OS routines will either enable interrupts or not work with interrupts off.
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Offline chickendude

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Re: Link Port help
« Reply #3 on: September 15, 2014, 08:34:13 am »
You can set up your own IM 2 interrupt which will also bypass TI's interrupts, but if you don't need your own interrupt just disabling it should be fine. I dunno if there's a system flag somewhere that handles that. It's also probably best to try to avoid OS routines as much as possible when messing with the link port unless you know they don't mess with the interrupts.
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