Suppose we want to show 6 levels of the stack instead of just the normal 4. 
Jake Schwartz wrote this one, called 'STACK':

<<
"6:                   "   @ initial 21-character string for line 6
  IF DEPTH 7 >=           @ if stack level 6 exists
  THEN 7 PICK ->STR       @    get it and convert to a string
  ELSE ""                 @    otherwise use a null string
  END 23 OVER SIZE        @ get size of object string
- 3 MAX SWAP REPL 1       @ position it right-justified in display string
DISP                      @ display in line one of LCD
"5:                   "   @ -- repeat
  IF DEPTH 6 >=           @    the same
  THEN 6 PICK ->STR       @    process
  ELSE ""                 @    for
  END 23 OVER SIZE        @    stack
- 3 MAX SWAP REPL 2       @    level 5 --
DISP 1 FREEZE             @ and freeze the status area of the LCD
>>

Now, save this as 'STACK', and save << DROP STACK >> as '*bENTER'.  Then,
whenever you're in user mode with flag -63 set, you'll see a six-level
stack automatically after all operations!  Notice that non-operation keys,
such as ATTN, the shift keys, and menu keys restore the normal display.

Of course, if you prefer, you may run STACK directly rather than using the
vectored enter method described above.

Note well that STACK is not really a replacement for the normal 4-high stack
display; it blows away the user's LASTARGs.