RE: LZ: ZShell, OS-85, C-Shell NT, OShell and all the rest
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RE: LZ: ZShell, OS-85, C-Shell NT, OShell and all the rest
On Tue, 3 Jun 1997, Jeff Tyrrill wrote:
> I think ON would be fine. The convenience would far outweigh the
> disadvantages. You wouldn't even half to press 2nd-ON to turn off the calc. To
> quit TI-BASIC programs, we could press ON-comma or some other key.
>
> I just thought of another complication. The interrupt handler would have to
> somehow disable the APD and use its own APD for the password protection to
> work with APD. And, the custom APD routine would have to know to not shut off
> when a BASIC or ASM program is running.
>
> It would probably be best not to build this feature into the shell. But an
> interrupt handler should definitely make it into the shell so this type of
> thing could be easily added.
The problem with the ON key is that: 1) Several games already use the ON
key to abort certain functions, etc (in ASM!!), and 2) when you press the
ON key only to turn off the calc, you must make a loop to ensure that the
ON key is not pressed at the time the processor actually enters the
powerdown routine... Else the calc will turn _right_ back on again...
Besides... If someone kept pressing the ON key continuously, when the
calc was turned back on you might have to enter the password a zillion
times before returning to the game...
About an interrupt handler: I ABSOLUTELY REFUSE to waste space (and my
time!) trying to get an interrupt handler and vector table to fit
correctly into the shell string! I would be perfectly willing to allow
CShell to place an interrupt handler (held in another string, so it would
be optional!) in graph mem and place an appropriate vector table in there
beside it... I would also be willing to try to write an interrupt handler
that would allow priority to be assigned, as well as multiple interrupts
(they would go together...), to certain interrupts defined by
programmers... however, I feel that most people who use the shells would
not really care about having an interrupt handler and vector REQUIRED in
the shell string itself... It would only make it larger and take up space
they would rather save for games!
I _WILL NOT_ place an interrupt handler and vector table INSIDE the
CShell string!!
~Michael
Cogito, ergo sum. Sum, ergo edo. Cogito, ergo doleo. Cogito sumere
potum alterum.
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