          VDPSTACK       subprogram                            PAGE  V2
          -------------------------------------------------------------

          Format         CALL VDPSTACK(numeric-variable)  


          Description

          The VDPSTACK subprogram allows change of location of the VDP
          STACK in VDP RAM. Care must be taken to where you place the
          stack after all any over write or change can crash XB.
          Normal VDP stack location is 2392 in decimal >0958 in Hex.
          Some XB programs like The Missing Link use 6176 or >1820 Hex.
          Another location would be like 4096 which is >1000 in Hex.
           Combine PRAM with VDPSTACK and Assemlby can be loaded into
          any memory locations previously very hard to use. That 
          required special loaders so now RXB has PLOAD and PSAVE to 
          get around these problems of loading anywhere in 32K now.

          Programs
 
          This line clears screen.      | >100 CALL CLEAR
          Set VDP STACK location.       | >110 CALL VDPSTACK(6176) 
          Display it.                   | >120 PRINT ">1820 STACK LOCAT 
                                        | ION"
          Show results.                 | >130 CALL SIZE
          Wait for key pressed.         | >140 CALL KEY("",0,S,S)
          Set VDP STACK location.       | >150 CALL VDPSTACK(4096)
          Display it.                   | >160 PRINT ">1000 STACK LOCAT
                                        | ION"
          Display it.                   | >170 CALL SIZE 
                                        |

          Options
          See PRAM for similar change to RAM locations. Also see 
          PLOAD and PSAVE for loading anywhere in 32K RAM.