(Comp.sys.hp48)
Item: 177 by detlef at mwhh.hanse.de
Author: [Detlef Mueller]
  Subj: Curiosities
  Date: Tue Nov 12 1991

Hi, out there.


How to view the TEMPOB area of your HP48 ?
------------------------------------------

Well, proceed as follows: download or enter the little (user-) RPL program
and run it:

%%HP: T(3);
\<<
    { #0 #0 } PVIEW      @ Switch to blackboard
    PICT PURGE           @ Set bb to size 0*0
    0 WAIT DROP          @ Wait for keystroke (in light sleep)
\>>

You now will see a bitmap image from the first kbyte of your temporary object
area.

What has happened ?

<PICT PURGE> will 1) resize the grob pointed to by GDISP to 0, 2) move the
referenced objects in the TEMPOB area down to the new free space. Because
there is no test if the GDISP grob is displayed, you will see now your
TEMPOB area. The workaround: insert a TEXT statement before you purge PICT.
Just a documentation of another curiosity of the HP48 operating system :-)