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