Product specifications

EX DE,HL ;Set the write to VRAM pointer
CALL VSETOT ;to give the correct VRAM
;address of the control block
;for the sprite which is to
;hold the locking off byte
LD C,208 ;Output the locking off byte
CALL VDOUTP ;to VRAM
RET ;Return to the calling routine
;
;DRWSPR-DISPLAY TWO SPRITES ON-SCREEN
;
; A YELLOW DIAMOND IN THE TOP LEFT HAND CORNER OF
; THE SCREEN
; A BLUE CIRCLE IN THE TOP RIGHT HAND CORNER OF THE
; SCREEN
;
; USES TABLE YDTL (YELLOW DIAMOND TOP LEFT)
; BCTR (BLUE CIRCLE TOP RIGHT)
;
YDTL: DB 1,1,0,11 ;Sprite 0 control information
;Byte 1 – Set Y coord to 1
;Byte 2 – Set X coord to 1
;Byte 3 – Display pattern 0
;Byte 4 – Pattern colour is dark
;yellow
BCTR: DB 1,247,1,5 ;Sprite 1 control information
;Byte 1 – Set Y coord to 1
;Byte 2 – Set X coord to 247
;Byte 3 – Display pattern 1
;Byte 4 – Pattern colour is light
;blue
;
DRWSPR: LD DE,(SATSAD) ;Set write to VRAM pointer to
CALL VSETOT ;start of sprite attribute table
LD B,8 ;Loop counter = 8
LD HL,YDTL ;Set pointer to start of sprite
;control data
DRWSP1: LD C,(HL) ;Output the control byte
CALL VDOUTP ;pointed to by HL to VRAM
INC HL ;Increment pointer to look at next
;data byte
DJNZ DRWSP1 ;Increment loop counter and if
;loop counter < > 0 then goto
;DRWSP1 else drop through to
;DRWSP2
DRWSP2: RET ;Return to calling routine
^(Illus 7 – Screen display of above)