; ; VLIB Module Name: VID1 ; Author: Richard Conn ; VLIB Version Number: 1.0 ; Module Version Number: 1.0 ; Module Entry Points: ; CLS ; Module External References: ; VIDPTR VIDOUT ; ext vidptr,vidout ; ; Clear Screen ; Return with A=0 and Zero Flag Set if not done ; cls:: push h ;save regs push d lhld vidptr ;pt to environment mov a,m ;no terminal? cpi ' '+1 jc clserr lxi d,14h ;pt to cls delay dad d mov d,m ;get it inx h ;pt to cls string inx h inx h mov a,m ;get first char of string ora a ;if no string, error jz clserr call vidout ;output string with delay pop d ;done pop h xra a ;return NZ dcr a ret clserr: pop d ;done pop h xra a ;return Z ret end