COMMENT *

			     CLUBware  (tm)

	  CLREOL clears the screen from the current position to the end
		  of the current line.	Cursor is left at starting
		  position.

		   Copyright 1984 Rayhawk Automation N.W. Inc
				  P.O. Box 1427
				  Beaverton, Oregon   97075

	  Algorithm:
		  1) determine current position
		  2) determine number of blanks required
		  3) write that many blanks using INT 10, AH=9


	  CALL	CLREOL ( FLAG% )

		  FLAG%       environment flag
			      = 0 means under basic interpreter
			      = 1 means under compiled basic
			      = 2 means under compiled business basic

									      *

;______________________________________________________________________________

;  Normal assembly directives

CODE	  SEGMENT PARA PUBLIC 'CODE'

	  ASSUME  CS:CODE

	  PUBLIC  CLREOL

ENV_FLAG	  EQU  WORD PTR [BP+6] ; address of environment flag on stack


;______________________________________________________________________________

CLREOL	  PROC	  FAR

	  PUSH	  AX		       ; save all registers used,
	  PUSH	  BX		       ;  no data segment local to this
	  PUSH	  CX		       ;  routine so segment registers
	  PUSH	  DX		       ;  are untouched.
	  PUSH	  ES


;	  ...	  0) load environment flag showing compiled or interpreted

	  MOV	  BX,ENV_FLAG	       ; load address of environment flag


;	  ...	  1) load current position from 0000:0450 if compiled
;		      or from DS:[0056h] if interpreted

	  SUB	  AX,AX 	       ; address system memory
	  MOV	  ES,AX

	  CMP	  WORD PTR DS:[BX],0	   ; check environment flag
	  JNE	  COMPILED

	  MOV	  DX,WORD PTR DS:[0056h]   ; load from basic space
	  XCHG	  DL,DH 		   ; basic has it reversed
	  DEC	  DL			   ; basic starts count from 1
	  DEC	  DH			   ;  instead of zero
	  JMP	  SHORT HAVE_POSITION

COMPILED:
	  MOV	  DX,WORD PTR ES:[450h]    ; load current position
					   ;  from system space
HAVE_POSITION:

;	  ...	  2) determine number of blanks required

	  MOV	  CX,80 	       ; first column on line is 0
	  SUB	  CL,DL 	       ; subtract off current column
	  JZ	  AT_END_OF_LINE       ; if zero, then already at end


;	  ...	  3) write that many blanks using INT 10, AH=9

	  MOV	  AX,0A20h	       ; AH = 10  and  AL = blank
	  MOV	  BX,0000h	       ; BH = 0 (assume always on page 0
				       ; use existing attribute
	  INT	  10h		       ; write that many blanks

AT_END_OF_LINE:
	  POP	  ES
	  POP	  DX
	  POP	  CX
	  POP	  BX
	  POP	  AX
	  RET	  2


CLREOL	  ENDP

;______________________________________________________________________________

CODE	  ENDS

	  END