\ VIDEO.SEQ     Direct VIDEO Screen output              by Tom Zimmer

FILES DEFINITIONS

VARIABLE VIDEO.SEQ

FORTH DEFINITIONS

VARIABLE ATTRIB   7 ATTRIB !-T          \ display attribute value
VARIABLE VIDEO-SEG                      \ Segment of display
VARIABLE TYPESEG       \ video type segment, the segment we are typing from.

CODE ?VMODE     ( --- N1 )
                MOV AH, # 15    INT 16          SUB AH, AH
                1PUSH           END-CODE

DEFER INITMONO  ' NOOP IS INITMONO      \ INITIALIZATION VECTOR AVAILABLE
DEFER INITCOLOR ' NOOP IS INITCOLOR     \ FOR MONOCHROME AND COLOR

HEX
: VMODE.SET     ( --- )
                ?VMODE 7 =
                IF      0B000   INITMONO
                ELSE    0B800   INITCOLOR
                THEN    VIDEO-SEG ! ;
DECIMAL

comment:

CODE VTYPE      ( string length x y -- )
                POP AX          \ Y
                POP DX          \ X
                POP BX          \ LENGTH
                PUSH BX         \ Save them back again
                PUSH DX
                PUSH AX
                ADD DX, BX      \ Set length + X position to DL
                cmp dx, # 79
             >= if
                        mov dx, # 79
                then
                mov #out dx
                MOV DH, AL      \ Move Y to DH
                XOR BX, BX      \ Clear BX
                MOV AH, # 2
                INT 16          \ Move cursor to end of typed string
                MOV AX, # 160
                POP BX          MUL BX          MOV DI, AX
                POP AX          SHL AX, # 1     ADD DI, AX
                POP CX          POP BX
                XCHG SI, BX                     \ SI is the source
                PUSH BX                         \ Save SI for later restoral
                PUSH ES                         \ save ES
                MOV AH, ATTRIB                  \ display attributes
                MOV ES, VIDEO-SEG               \ destination segment
                MOV DS, TYPESEG                   \ source segment
LABEL VTYPE1    LODSB           STOSW           \ Move a byte to display
           LOOP VTYPE1                          \ LOOP till CX is zero
                POP ES                          \ restore ES
                POP SI                          \ Restore IP
                MOV BX, CS      MOV DS, BX      \ restore DS
                NEXT            END-CODE

DECIMAL

comment;