TITLE BLANKT -- blank terminal screen code for mailsystem
	SUBTTL Written by Mark Crispin /MRC 5-Apr-85

	SEARCH MACSYM,MONSYM	; system definitions
	SALL			; suppress macro expansions
	.DIRECTIVE FLBLST	; sane listings for ASCIZ, etc.

;  This module contains code to blank the terminal screen.  This is
; site-dependent and should be edited for each individual site as
; appropriate.

A=:1				; JSYS AC's
B=:2

	.PSECT CODE

$BLANK::SAVEAC <A,B>
	STKVAR <TTYPE,OLDMOD>
	MOVEI A,.PRIOU		; get terminal type index
	GTTYP%
	MOVEM B,TTYPE		; save for later
	CAIGE B,NCLRSC		; more than the number supported?
	 SKIPN CLRSCN(B)	; yes, able to blank on this type?
	  RET			; no, return
	RFMOD%			; get current terminal mode
	MOVEM B,OLDMOD		; save for later
	TRZ B,TT%DAM		; change to binary mode
	SFMOD%
	MOVE B,TTYPE		; get type index back again
	MOVE A,CLRSCN(B)	; get blanking sequence or address
	TXOE A,.LHALF		; was it an address (LH=0)?
	 HRROI A,CLRSCN(B)	; no, sequence 4 chars or less, set up address
	PSOUT%			; output the sequence
	MOVEI A,.PRIOU		; wait for it to get out
	DOBE%
	SETZ B,			; tell monitor we are at top of page
	SFPOS%
	MOVEI A,^D500		; give terminal a chance to do it
	DISMS%
	MOVEI A,.PRIOU		; restore former terminal mode
	MOVE B,OLDMOD
	SFMOD%
	RET			; now return

DEFINE CLRASCII <BYTE (7) .CHESC,"H",.CHESC,"J",0> ; ASCII screen clear
DEFINE CLRANSI <[BYTE (7) .CHESC,"[","H",.CHESC,"[","J",0]> ; ANSI standard

CLRSCN:	0			; 0 TTY33
	0			; 1 TTY35
	0			; 2 TTY37
	0			; 3 TI
	0			; 4 reserved for customer definition
	0			; 5 reserved for customer definition
	0			; 6 reserved for customer definition
	0			; 7 reserved for customer definition
	0			; 8 default
	0			; 9 PTY, NVT (aka "ideal")
	BYTE (7) .CHCRB,.CHCUN,.CHCUN,.CHCUN,0 ; 10 VT05
	CLRASCII		; 11 VT50
	0			; 12 LA30
	BYTE (7) .CHCRB,.CHCUN,0 ; 13 GT40
	0			; 14 LA36
	CLRASCII		; 15 VT52
	CLRANSI			; 16 VT100
	0			; 17 LA38
	0			; 18 LA120
	0			; 19 reserved for customer definition
	0			; 20 reserved for customer definition
	0			; 21 reserved for customer definition
	0			; 22 reserved for customer definition
	0			; 23 reserved for customer definition
	0			; 24 reserved for customer definition
	0			; 25 reserved for customer definition
	0			; 26 reserved for customer definition
	0			; 27 reserved for customer definition
	0			; 28 reserved for customer definition
	0			; 29 reserved for customer definition
	0			; 30 reserved for customer definition
	0			; 31 reserved for customer definition
	0			; 32 reserved for customer definition
	0			; 33 reserved for customer definition
	0			; 34 reserved for customer definition
	CLRANSI			; 35 VT125
	CLRANSI			; 36 VK100 (GIGI)
	CLRANSI			; 37 VT102
	CLRASCII		; 38 H19
	CLRANSI			; 39 VT131
	CLRANSI			; 40 VT200
	0			; 41 reserved for customer definition
	0			; 42 reserved for customer definition
	0			; 43 reserved for customer definition
	0			; 44 reserved for customer definition
	0			; 45 reserved for customer definition
	0			; 46 reserved for customer definition
	0			; 47 reserved for customer definition
	0			; 48 reserved for customer definition
	0			; 49 reserved for customer definition
	0			; 50 reserved for customer definition
	0			; 51 reserved for customer definition
	CLRANSI			; 52 VT300
	0			; 53 reserved for Digital defintion
	0			; 54 reserved for Digital defintion
	0			; 55 reserved for Digital defintion
	0			; 56 reserved for Digital defintion
	0			; 57 reserved for Digital defintion
	0			; 58 reserved for Digital defintion
	0			; 59 reserved for Digital defintion
	0			; 60 reserved for Digital defintion
	0			; 61 reserved for Digital defintion
	0			; 62 reserved for Digital defintion
NCLRSC==.-CLRSCN		; maximum # of terminal types

	END