Re: A86: Questions on Port 3, calc on, off, APD, etc
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Re: A86: Questions on Port 3, calc on, off, APD, etc
In a message dated 5/27/98 11:03:39 PM Eastern Daylight Time, Ti86ROM@aol.com
writes:
> In a message dated 98-05-27 21:49:24 EDT, you write:
>
> << Hey this is Matt. I have been disassembling the ROM and I have a few
> questions
>
> 1.) Does anyone have any details on Port 3? Does it operate on bits, or
> does
> it recognize bytes themselves at different
> instructions? Why does so many Rom routines write two bytes to them? These
> are written to Port 3 often - $00 $01
> $09 $0B, $0A $0B. I read the latter were that $09 for the ON key being
off,
> $0A for the on key being on
>
> 2.) What exactly is an ON interrupt vs. ON key pressed and a timer
> interrupt
> vs. whether timer has occured. These are some of the bits read. Can an ON
> interrupt occur without the ON key being pressed? The rom seems to check
> for
> that possibility. How are the bits that you write relate to the bits that
> you read?
>
> 3.) When the calculator is off, does the interrupts run in the background
> or
> does it disable timer interrupts and wait for an ON interrupt. Does anyone
> have any details on this?
>
> 4.) The calculator appears to turn on immediately when you put batteries
in
> it, executes a HALT and waits for the ON key before it initializes. Is
this
> correct?
> Yes, that is correct.
>
> 5.) Does the calculator do different things if it is shut off depending on
> whether it what caused by the APD shut it off or [2nd][ON]. It appears to
> have a difference
> yes, it doesn't flush the menu's + return to the home screen w/ APD
>
> Anyone have any idea? Dan Eble? Jimmy Mardell? Trent Lillehaugen? Anyone?
> >>
>
it's not a big deal, but could you use internet style quoting instead of aol
style? that way people can spot your comments MUCH easier
thanks