Re: LF: Keepout/Password Ideas
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Josh Hays wrote:
>
> > I think it would be nice if you could rig your programs so they would be
> > triggered by pressing diamond+on.
> > <rest deleted>
>
> Interesting idea; the only problem is that diamond-on is already
> bound to turn off the TI-92 through the 92's ROM, and I don't believe
> that it can be rebound through software.
>
> Later,
> Josh Hays | jhays@teaser.fr
Actually, all you would have to do is change the vector table in the
begining of ram. the file called "traps.txt" that came with fargo
explains this somewhat.
--- from traps.txt ---
The 68000 processor keeps a 256(d) byte exception vector table at the
bottom
of memory (address $000000). This table contains pointers to 64(d)
vectors;
each vector is an absolute pointer to a specific location in memory.
Most of
these vectors point to routines, although some have other functions.
Each
vector is referred to with an index between 0(d) to 63(d) inclusive.
...
0064 to 007F Level 1-7 interrupt auto-vectors (25-31)
0080 to 00BF TRAP #0-15 instruction vectors (32-47)
...
Auto-Int 6
----------
Triggered when [ON] is pressed.
Auto-Int 7
----------
Protected memory violation. Triggered when memory below [$000120] is
written while bit 2 of [$600001] is set.
...
Trap 4
------
Turn Off, Turn On (see also Auto-Int 6)
Input : nothing
Output: calculator turns off, waits for [ON]
--- end traps.txt exerpts ---
the portions of memory contain a pointer to the address to jump to when
a specific action occurs. Before you change any of these, you must
disable the protected memory violation "auto-int" (#7 above) (I just saw
this, that's why this stuffwasn't working for me.)
anyway, you just change the address pointer for the "on" auto-int (#6)
if you want to trigger the password program. you should also save the
address already refrenced, and jsrr to there after your routine. But
even better would be to attach to trap 4, that turns off the calc.
Whenever the calc tries to shut off, it will trigger your routine. you
can jump to the real trap 4 routine, shut off the calc, then execute you
password program as soon as the calc turns back on, instead of returning
right to the previous task. you could have password protection even
after an auto powerdown.
hope this helps.
<pre>
--
Christopher Poole
poole.christopher@paradox.net
http://www.paradox.net/homepages/poole
http://mycorner.home.ml.org
http://poole.home.ml.org
</pre>
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