;
; Example of use of display list
; interrupt from Action
;

BYTE   VCOUNT = $D40B,
       WSYNC = $D40A,
       NMIEN = $D40E,
       CH = $2FC,
       COLPF2 = $D018

CARD   VDSLST = $200,
       SDLST = $230,
       OLDVEC

DEFINE PHA = "$48",
       PLA = "$68",
       TAX = "$AA",
       TAY = "$A8",
       TXA = "$8A",
       TYA = "$98",
       RTI = "$40"

;
; During a DLI you can't call any
; other functions, nor multiply,
; nor divide
;

PROC DLI()
  [PHA TYA PHA TXA PHA]
  WSYNC = VCOUNT
  COLPF2 = VCOUNT
  [PLA TAX PLA TAY PLA RTI]

PROC MAIN()
  BYTE I
  BYTE POINTER TEMP
  PRINTE("Setting up DLI")

  NMIEN = $40  ;DISABLE DLI

  OLDVEC = VDSLST
  VDSLST = DLI

  TEMP = SDLST+3
  TEMP^ = $C2

  FOR I = 1 TO 23
  DO
    TEMP = SDLST + I + 5
    TEMP^ = $82
  OD

  NMIEN = $C0 ;ENABLE DLI

  WHILE CH = $FF DO
    PRINTE("Press any key to quit")
  OD
  CH = $FF ;Swallow key press

  PrintE("Restoring DLI")

  NMIEN = $40 ;DISABLE DLI
  TEMP = SDLST+3
  TEMP^ = $42

  FOR I = 1 TO 23
  DO
    TEMP = SDLST + I + 5
    TEMP^ = $02
  OD

  VDSLST = OLDVEC
  PRINTE("Returning")
 RETURN

-------
VBL.ACT
-------
;
; Example of using the vertical blank
; deferred interrupt from Action
;

BYTE   RTCLOCK = 20,
       CH = $2FC,
       COLOR2 = $2C6

CARD   VVBLKD = $224,
       SDLST = $230,
       OLDVEC

DEFINE JMPI = "$6C"

;
; Within a VBI you can't call any
; subroutines, nor can you multiply
; or divide. . . .

PROC VBLANKD()
  COLOR2 = RTCLOCK
  [JMPI OLDVEC]

;Simulate the OS call SETVBV

PROC SETVBV(BYTE WHICH
            CARD ADDR)
  CARD POINTER TEMP
  BYTE V
  TEMP = $216 + (WHICH LSH 1)
  V = RTCLOCK+ 1
  WHILE V <> RTCLOCK DO OD
  TEMP^ = ADDR
  RETURN

PROC MAIN()
  BYTE OLDC2

  OLDC2 = COLOR2
  PRINTE("Setting up Vblank")

  OLDVEC = VVBLKD
  SETVBV(7, VBLANKD)

  WHILE CH = $FF DO
    PRINTE("Press any key to quit")
  OD
  CH = $FF ;Swallow key press

  PrintE("Restoring Vblank")

  Setvbv(7, OLDVEC)
  COLOR2 = OLDC2
  PRINTE("Returning")
 RETURN