Re: LZ-Adv: ZShell for TI-82 -- Ideas..


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Re: LZ-Adv: ZShell for TI-82 -- Ideas..



>Now, how does this work? At $818d in TI-85 RAM is a pointer to the
>routine that will hande a keyboard press. The key is to  change this
>address to point at some location where you can put your own asm-code.
>I achieved this by, in a backup file, changing the VAT-pointer for a
>real variable to point at this $818d. After transferring the backup to
>the calc, I can store whatever I want (almost) to this location. In
>this case I store E145 to the real variable. E145 equals
>0091FC00000000000000 which means that $818d will contain a pointer to
>9100. At 9100 it is simple to put a fixed variable containing the
>asm-code. (I just extended the ZShell string, Quick&Dirty! ) In my 
>backup file
>the code at 9100 first restores $818d and then the following words
>(which are also destroyed by storing the real (the values of these
>words appear not to be critical)). Then I jump to ZShell.


Okay... but how do you keep from rnning ZShell every time a key is
pressed?


Jason "Thursday" Wenger
jwenger@juno.com
Illegitimi no carborundum


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