Re: A86: Memory Lock

To: assembly-86@lists.ticalc.org
Subject: Re: A86: Memory Lock
From: Dux Gregis <assets@eden.rutgers.edu>
Date: Tue, 10 Mar 1998 22:14:04 -0500
Delivered-To: assembly-86-outgoing@towerguard.unix.edu.sollentuna.se
References: <3505FE1F.72C7E594@eden.rutgers.edu>
Reply-To: assembly-86@lists.ticalc.org




Dux Gregis wrote:

> The [sqrt]KEY program is called (under the right conditons) after the
> _getkey (or possibly _getky in certain calc states) is called and before
> the key press is checked.  This is a model of how to create and use
> [sqrt]KEY.  I haven't tested it though, so proceed with cation.
>
> ;To create the program:
>
>  ld hl,op_info
>  rst 20                ;[sqrt]KEY -> OP1
>  ld hl, code_end - code
>  call $474f            ;creates program
>  set 6,(iy+24)       ;enables program
>  ret
>
> op_info:
> .db $12, $4,$10
> .db "KEY",0
>
> ;Here's what some possible [sqrt]KEY code could look like:
> ;(this is intended to override the enter keypress in the delete state)
>
> code:
>  call $479f            ;special call
>  ld a,($d625)        ;don't ask me
>  bit 0,(iy+$20)
>  jr nz,skip_key        ;skip if flag not set
>  push af                ;push getkey
>  ld a,($c1b4)        ;load calc state
>  cp $23                ;check if in delete state
>  jr nz,skip_key

;Change this to skip_key2; I missed a pop af

>  pop af                ;pop getkey
>  cp $06                    ;check for enter press  (might be $09
> instead?)
>  jr nz,skip_key
>  xor a                ;0 out the getkey
> skip_key:
>  cp a                    ;can't hurt
>  ret

;And add:skip_key2:
 pop af
 jr skip_key

> code_end:

References:

A86: Memory Lock

From: Dux Gregis <assets@eden.rutgers.edu>