A82: Re: ASM shells crashing calc
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A82: Re: ASM shells crashing calc
First of all i am pretty sure that the dummy vars are not the problem, nd
the misreported size is not a problem either. The main problem with you
method is that the problem occurs as soon as you start the shell, so even
if you only started it once that way your calc could crash. Interrupts are a
possible way of starting a shell, but if you do not use the ints for other
things than starting the shell i think it is a wast of space (the int table
takes up 257 bytes). Jason Todd and i have been talking about adding a
feature like this, but nothing is sure yet.
Dines
-----Original Message-----
From: Jeff Tyrrill <Jeff_Tyrrill@msn.com>
To: Assembly-82 Message Posting (E-mail) <assembly-82@lists.ticalc.org>
Date: 13. september 1997 07:32
Subject: A82: ASM shells crashing calc
>I'm not very familiar with the methods the shells use to execute
>themselves, but here's a possible solution. As I understand it, a pointer
>in the RAM is changed to point to the ASM code of the shell, but this
>modification causes other problems such as the misreported variable sizes,
>the use of a "dummy" variable, and the frequent crashes. How about if the
>shell used this method to execute itself the first time after it was
>transferred to the calc, but when it was run the first time, it would
>install a TSR, and restore the changed pointer to its original state, so
>the crashing and misreported variable sizes would not occur. To run the
>shell again, the TSR would monitor for a combination of keys being held
>down. So for example, when the buttons PRGM and MATH are pressed together,
>the shell would launch.
>
>I could be wrong about this, but it seems like it would work.
>________________
>
>Jeff Tyrrill
>http://tyrrill-ticalc.home.ml.org/
>http://ti-files.home.ml.org/
>
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