
.Cls
   STMFD    R13!,{R4-R9,R14}
   LDR      R0,Gcol_Back_Colour
   MOV      R1,R0
   MOV      R2,R0
   MOV      R3,R0
   MOV      R4,R0
   MOV      R5,R0
   MOV      R6,R0
   MOV      R7,R0
   LDR      R8,Screen_Start
   LDR      R9,Screen_Size
   ADD      R9,R8,R9

.Cls_Loop
   STMIA    R8!,{R0-R7}
   CMP      R8,R9
   BNE      Cls_Loop
   LDMFD    R13!,{R4-R9,R15}
