;**************************************************
;*                                                *
;*  USER-MODIFYABLE ROUTINES AND CONSTANTS FOR    *
;*  HARDWARE-DEPENDENT TERMINAL CHARACTERISTICS   *
;*  AND FUNCTIONS USED BY WORD-MASTER.            *
;*                       RELEASE 1.07   2/21/80   *
;**************************************************
;

; *** SUBROUTINE TO CLEAR SCREEN AND HOME CURSOR ***
;
; THIS VERSION WORKS FOR THE HEATH H89 OR H19 TERMINAL
;
        ORG     180H
OUTCHR  EQU     01EFH   ;OUTPUT CHARACTER FOR RELEASE 1.07
MEMORY  EQU     29B8H   ;USER PATCH AREA FOR RELEASE 1.07
CLRSCRN: NOP! NOP! NOP  ;SPACE FOR LONGER PATCH /
         NOP! NOP! NOP  ; MAKE ADDRS MATCH OLD VERSION
    ;FIRST, SEND ESCAPE, E.
        MVI A,1BH       ;(1) GET ESCAPE CHARACTER
        CALL OUTCHR     ;SEND IT TO TERMINAL
        MVI A,'E'       ;(2) GET ASTERISK
        CALL OUTCHR     ;SEND IT TO TERMINAL
        RET
;
; *** SUBROUTINE TO POSITION CURSOR AT      ***
; ***     LINE L (0=TOP), COLUMN H (0=LEFT) ***
;
; SENDS ESCAPE, Y, Y+20H, X+20H (ESC-Y IS H19 DIRECT
;                               CURSOR ADDRESSING SEQUENCE)
;
 TCURSOR: MVI A,1BH! CALL OUTCHR        ;SEND ESCAPE
        MVI A,'Y'! CALL OUTCHR  ;SEND EQUALS
        MVI A,20H               ;ADD 20 HEX...
        ADD L                   ;.. TO LINE #...
        CALL OUTCHR             ;.. AND SEND IT.
        MVI A,20H               ;ADD 20 HEX...
        ADD H                   ;..TO COLUMN NUMBER
        CALL OUTCHR             ;..AND GO SEND IT.
        RET

        DB 0,0,0,0,0    ;ADDITIONAL PATCH SPACE
        DB 0,0,0,0,0    ;...


        ;NOTE: BACKSPACE ROUTINE THAT WAS IN
        ;PRIOR RELEASES IS NO LONGER NEEDED.

; **** MODIFYABLE CONSTANTS *****

 ;PBEGMEM POINTS TO BEGINNING OF MEMORY TO USE
 ;FOR EDIT BUFFER AND SCRATCHPAD. IF SPACE IS NEEDED
 ;FOR PATCHES, PUT THEM WHERE THIS POINTS AND
 ;INCREASE THIS POINTER. REMEMBER TO USE A LARGE
 ;ENOUGH "SAVE" COMMAND!

PBEGMEM: DW MEMORY

 ;SCREEN SIZE: TAKEN FROM THE FOLLOWING,
 ;EXCEPT SET AUTOMATICALLY TO MATCH HARDWARE

HITE:   DB 24   ;MUST BE EXACT SCREEN HEIGHT IN LINES
WID:    DB 80   ;MUST BE <= EXACT SCREEN WIDTH

 ;EREOL CONTAINS THE CHARACTER(S) TO ERASE SCREEN
 ;TO END-OF-LINE WITHOUT MOVING CURSOR

EREOL:  DB 1BH  ;(FIRST) CHARACTER -- ESC
        DB 'K'  ;SECOND CHARACTER -- K IS ERASE
                ;           TO END OF LINE

NOVIO:  DB 0
        DB 0,0,0        ;RESERVED FOR EXPANSION


;DELAYS EXECUTED AFTER VARIOUS TERMINAL FUNCTIONS,
;BEFORE NEXT CHARACTER IS SENT TO TERMINAL. THESE
;ALLOW TIME FOR TERMINAL TO RESPOND, AS REQUIRED
;BY SOME TERMINALS WHEN USED AT HIGH BAUD RATES.
;INCREASE IF YOU EXPERIENCE, FOR EXAMPLE, LOSS OF
;CHARACTERS AFTER CLEAR SCREEN.  EACH DELAY IS
;APPROX NUMBER OF MILLISECONDS ON 4MHZ PROCESSOR;
;DELAY IS TWICE AS LONG AS SHOWN FOR 2MHZ 8080.

DELCLR: DB 25   ;DELAY AFTER CLEAR SCREEN: 25+ MSEC.
DELCUS: DB 10   ;DELAY AFTER POSITION CURSOR: 10+MSEC.
DELERE: DB 5    ;DELAY AFTER ERASE TO EOL: 5+ MSEC.


        DB 0,0,0,0,0            ;MORE 
        DB 0,0,0,0,0            ;EXTRA
        DB 0,0,0,0,0            ;PATCHING
        DB 0,0,0,0,0            ;SPACE
                
        END