A92: RE: Handle's Messiah

• To: <assembly-92@lists.ticalc.org>
• Subject: A92: RE: Handle's Messiah
• From: "Niklas (EFD)" <e96nbr@efd.lth.se>
• Date: Sun, 15 Mar 1998 12:36:51 +0100
• Delivered-To: assembly-92-outgoing@towerguard.unix.edu.sollentuna.se
• Reply-To: assembly-92@lists.ticalc.org

>
>Sorry for the pun.  I have been totally confused with handles.  I can
>allocate and free them without any trouble.  But I can't seem to use them.
>I get "Address Error" and "Line 1111 Emulator" errors.  Am I completely
>using them incorrectly?  (see the following code)
>
>move.l  #2,-(a7)
>jsr tios::HeapAlloc
>lea     4(a7),a7
>cmp.l   #0,d0
>beq \UnableToAlloc

OK so far...

Here's where you go wrong:
>move.w  d0,a0
>clr.w   0(a0)


The value in d0.w is the handle - NOT the adress. To get the adress that the handle points to, use this:
tios::DEREF    d0,a0

Note that this destroys d0 (I think, read tios.h). Also, tios::DEREF is a macro. You can cut'n'paste the code into your own program if you don't want to destroy d0. You can also get the adress in another adress register.

>move.w  d0,-(a7)
>jsr tios::HeapFree
>lea     2(a7),a7
>\UnableToAlloc:
>
>Does this program correctly allocate 2 bytes, clear them, and then free the
>memory?


Two out of three ain't bad ;-)

• Prev: A92: Handle's Messiah
• Next: A92: Re: TI-89 Screen size and FLASH memory
• Index(es):
  • Main
  • Thread