TITLE	"VIDE - Vlib 4.3"
	NAME	('VIDE')
;=================================================================
;  Copyright (C) 1989 by Harold F. Bower.  Permission granted to
; Alpha Systems Corp. to distribute with The Libraries, Version 4
;-----------------------------------------------------------------
; Author  : Harold F. Bower
; Date    : 3 Mar 89
; Version : 1.0
; Module  : VIDE
; Abstract:  This module contains the routines GRXON and GRXOFF
;	which change the terminal mode to graphics (GRXON) and
;	and back to alphanumeric (GRXOFF).
; Revision:
;	1.1  13 Dec 89  Joe Wright
;	Add CUROFF and CURON cursor controls.
;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
;  Module Entry Points

	PUBLIC		GRXON, GRXOFF, CURON, CUROFF

;  External References

	EXT		@SETV0, @GE, @GO, @GOELD, @CDE, @CDO

	.Z80
	CSEG
;===============================================================
; GRXON - Enter Graphics Mode
;  Entry: - None
;  Exit :  A = 0 and Zero Flag Set (Z) if Error
;	   A = FFH and Zero flag Reset (NZ) if Operation OK
;  Uses : AF
; Special Requirements: None
;===============================================================

GRXON:	PUSH	HL		; Save regs
	LD	HL,(@GO)	; Get address for Graphics ON string
	JR	GRXO0		; ..and continue below

;===============================================================
; GRXOFF - Exit Graphics mode
;  Entry: - None
;  Exit :  A = 0 and Zero Flag Set (Z) if Error
;	   A = FFH and Zero flag Reset (NZ) if Operation OK
;  Uses : AF
; Special Requirements: None
;===============================================================

GRXOFF:	PUSH	HL		; Save regs
	LD	HL,(@GE)	; Get address for Graphics OFF string
GRXO0:	LD	A,(@GOELD)	; ..and delay value
	JP	@SETV0		; Finish off in other module

;===============================================================
; CUROFF - Turn Cursor Off
;  Entry: - None
;  Exit :  A = 0 and Zero Flag Set (Z) if Error
;	   A = FFH and Zero flag Reset (NZ) if Operation OK
;  Uses : AF
; Special Requirements: None
;===============================================================

CUROFF:	PUSH	HL
	LD	HL,(@CDO)
	JR	GRXO0

;===============================================================
; CURON - Turn Cursor On
;  Entry: - None
;  Exit :  A = 0 and Zero Flag Set (Z) if Error
;	   A = FFH and Zero flag Reset (NZ) if Operation OK
;  Uses : AF
; Special Requirements: None
;===============================================================

CURON:	PUSH	HL
	LD	HL,(@CDE)
	JR	GRXO0

	END