Re: A86: Edit lock

To: assembly-86@lists.ticalc.org
Subject: Re: A86: Edit lock
From: the_laser@juno.com (Andy S Johnson)
Date: Sun, 8 Feb 1998 11:59:12 -0700
References: <199802081752.JAA07261@bonzo.org>
Reply-To: assembly-86@lists.ticalc.org

Not quite right.  All programs start with a three byte absoulte address
length.  It's just that the third byte is usually zero unless you have a
very large program.  But as for the extra null, it seems right.  Now the
question is how this null byte can be added through asm.  I guess you
would just have to create a new program one byte longer, copy the
contents over and delete the first.
---
Andy Johnson
"Change is inevitable...
     except from vending machines"

On Sun, 8 Feb 1998 12:46:34 +0000 jima@tso.cin.ix.net writes:
>
>Umm.. I think you're all wrong but no offence.  It doesn't change the 
>program type.. All basic programs start with a two byte size and then 
>a null byte ($00). After that comes the actual text. If you want it 
>to be locked, just add a second null byte after the first.. Let's say 
>you use this test program:
>
>:DISP "HI"
>
>The data would go like this for unlocked:
>$0A00                ;the size
>$00                     ;null byte
>$444953502022484922                     ;the text 'DISP "Hi"'
>
>Now for the locked version, it would be like this:
>$0B00                ;size is one bigger for the extra null byte 
>$0000                 ;null bytes needed for being locked 
>$444953502022484922                     ;the text 'DISP "Hi"'
>
>> On the computer, there is a protection option for programs.  What I 
>believe
>> this does is it changes the program type from $12 to maybe $32 (I 
>haven't
>> checked on the 86) and then it disappears from the edit menu.  You 
>can also
>> edit protect a program with $FF but then it is somewhat permanent.
>> 
>> -----Original Message-----
>> From: Klukan <renegade@bmt.net>
>> To: assembly-86@lists.ticalc.org <assembly-86@lists.ticalc.org>
>> Date: Sunday, February 08, 1998 12:37 AM
>> Subject: Re: A86: Edit lock
>> 
>> 
>> |
>> |TGaArdvark@aol.com wrote:
>> |
>> |> > an edit locked program (as far as i know) has a null (00h) as 
>it's
>> |> last
>> |> > character. can someone verify this?
>> |>
>> |> No, not basic anyway (I think it's a different type of variable 
>for
>> |> asmcomped asm). For basic, it's a $FF anywhere in an un-
>> |> executed portion of the program that has no gotos that go
>> |> across it (Lbl searches crash on $FF's too).
>> |
>> |As far as I know, ASM programs cannot be edit-locked.  For BASIC, 
>it is
>> |a $FF character that causes the program to become edit-locked.  I 
>think
>> |that it must come at the end of the program, but I am not sure 
>about
>> |that.  ASM programs do not really need to be edit-locked, since 
>once
>> |they are compiled, there is no way to edit them.  That is unless 
>you
>> |decompile it, which would generate code that is uncommented and is 
>full
>> |of pointers and such.  Anyway, there are programs that can 
>un-edit-lock
>> |programs, so the feature is pretty much useless anyway.
>> |
>> |-Jeremy
>> |
>> |
>> 
>> 
>

_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]
References:
Re: A86: Edit lock
From: jima@tso.cin.ix.net