Programmer 7500/MAX_PROGRAMMERS.iso/INFO/QBASIC/VIDBASIC.ZIP/VPRINTL.ASM

Assembly Source File | 1990-11-29 | 12.6 KB | 340 lines

;«RM82»«TS8,16,24,32,40,48,56,64»
; Updated 11/20/90

;============================================================================
;   Copyright (C) Copr. 1990 by Sidney J. Kelly
;           All Rights Reserved.
;           Sidney J. Kelly
;           150 Woodhaven Drive
;           Pittsburgh, PA 15228
;           home phone [phone] (7pm to 9:30pm EST)
;============================================================================

DOSSEG
.model medium, Basic
.data
    ;external data so all video routines can access
    EVEN
    EXTRN   B$DVIDEOSEG:WORD
    EXTRN   B$DVIDEOPORT:WORD
    EXTRN    B$DVIDEODI:WORD
    EXTRN   B$DVIDEOINSTL:BYTE
.code

INCLUDE NOWAIT.INC
EXTRN   Get_Adapter:FAR
EXTRN    SET_DI:FAR

.code
EVEN
VPageSize    dw      3998       ; default page size of 80 x 25
VDI_Reset    dw      3840       ; default offset of Row 25, col 1
VAttrib      db      7          ; default color of white on black
VRow         db      24         ; default number of rows  (0 bias)
VColumn      db      79         ; default number of columns (0 bias)

;===========================================================================
; DECLARE SUB SETQP (BYVAL ROW%, BYVAL COLL%, BYVAL Attribute%)
;         CALL SETQP(ROW%, COLL%, Attribute%)
; Purpose:
;         Initializes varibles, and sets DI to target address.  This is the
; initialization routine for QPRINTL.  Selects the attribute used to
; scroll the display upward.
; Assumes that user wants to set page size to full size of current dsp
; such as 80 x 25, 80 x 43, or 80 x 50
;===========================================================================

EVEN
SETQP PROC FAR BASIC USES SI DI, ROW:WORD, COLL:WORD, ATTRIB:WORD
    Assume  DS:@data

    Cmp     B$DVIDEOINSTL,1 ;See if we have done this before
    JE      Didit        ; yep, so skip ahead
    Call    Get_Adapter  ; call routine to find display type

Didit:
    Mov     BX,ATTRIB    ; read attribute from stack
    Or      BL,BL        ; make sure that BL <> 0
    JNZ     @f           ; if BL <> 0 then skip ahead
    Mov     BX,7         ; else give normal attribute
@@:
    Mov     VAttrib,BL   ; store attribute
    Mov     BX,ROW       ; read value of Row
    Dec     BX           ; convert to BIOS format
    Cmp     BX,24        ; check if within range 1 to 25
    JBE     @f           ; if w/in bounds o.k.
    Xor    BL,BL        ; else make it Row 1
@@:
    Mov     DH,BL        ; store ROW (BL) in DH

    Mov     BX,COLL
    Dec     BX           ; convert to BIOS format
    Cmp     BX,79        ; check if within range 1 to 80
    JBE     @f           ; if w/in bounds o.k.
    Xor    BL,BL         ; else make it Column 1
@@:
    Mov    DL,BL        ; store COLL (BL) in DL

    CALL    SET_DI       ; call routine to find video seg offset in DI
    Mov     B$DVIDEODI,DI ; store DI

    Xor     AX,AX        ; read current bios values
    Mov     ES,AX        ; set ES to BIOS ram area
    Xor     BH,BH        ; clear high byte
    Mov     BL,Byte Ptr ES:[0484h]  ; read ROW from BIOS ram
    Or      BL,BL        ; is ROW 0? (i.e. is this CGA, HERC or MONO?)
    JNZ     @f           ; nope, it is a EGA, MCGA or VGA
    Mov     BL,24        ; set default ROW to 24
@@:
    Mov     VRow,BL      ; store number of ROW
    Inc     BL           ; remove 0 bias of ROW
    Mov     AX,ES:[044Ah]; read COLUMN from BIOS ram
    Dec     AL           ; make it zero biased
    Mov     VColumn,AL   ; store number of columns with 0 bias
    Inc     AL           ; remove zero bias
    Mul     BX           ; multiply ROW times COLUMN
    Add     AX,AX        ; multiply AX by 2  (3 clocks on 8088)
    Sub     AX,2         ; reduce by 2       (3 clocks on 8088)
    Mov     VPageSize,AX ; store Page_Size in memory
    Xor     AH,AH        ; clear AH
    Mov     BH,AH        ; also clear BH
    Mov     AL,VRow      ; get row in AL (it is 0 biased)
                 ; the following shows the work necessary
                 ; if you allow display widths other than 80
    Mov     BL,VColumn   ; load number of columns into BL
    Inc     BL           ; remove zero bias
    Add     BX,BX        ; multipy Column times 2
    Mul     BX           ; multiply Rows * (Columns * 2)
    Mov     VDI_Reset,AX ; store result from AX in VDI_Reset
                 ; this is offset of Last line, Column 1
    Ret
SETQP ENDP


;===========================================================================
; DECLARE SUB QPRINTL (Text$)
;         CALL QPRINTL(Text$)
; Usage: CALL SETQP(ROW%, COLL%, Attribute%) the first time to set
; the defaults to current display size.  Then QPRINTL on down the display.
; You should use SETQP to start, since scroll routine needs the proper
; attribute to scroll the screen up.
;
; Purpose:
;         To work similarly to PRINT Text$;
;
;         Major differences are:
;         a)  Assumes that a VIEW PRINT has been executed
;         b)  will not parse the Text$ and start a new line if length of
;           Text$ is longer than remaining space on current line.  PRINT
;           is designed for formatted column printing, while this
;           routine is not.
;         c) if at Last Row, Column 80, QPRINTL will scroll the display
;            can't stop it.
;
; Speed:
;       Varies with length of Text$ and length of display
;         for a color EGA on a 10 Mhz AT, the speed varies from 3% faster
;         (if LEN(Text$) = 80) to 48% faster.
;         Typical speed increase is 12%
;===========================================================================
EVEN
QPRINTL PROC FAR BASIC USES SI DI, TEXTSTRG:WORD

    Mov    ES,B$DVIDEOSEG    ; restore the initialized values
    Mov    DX,B$DVIDEOPORT    ; puts 0 in DX if not CGA
    Mov    BL,VAttrib    ; get attribute
    Mov    AH,BL        ; store attribute in AH
    Mov    BH,BL        ; store attribute in BH too for use in _Rollup
    Mov    SI,TEXTSTRG     ; put descriptor to TEXT$ into SI
    Mov    CX,[SI]         ; put Len(TEXT$) into CX for loop counter
    JCXZ    Exit1           ; if CX is zero it's a null string, exit now
    Mov    SI,[SI+02]      ; put address of first character in X$ into SI
    Cld            ; clear the direction flag to move data forward
    Mov    DI,B$DVIDEODI   ; set DI to reflect last call

Main_Loop:
    Or    DX,DX        ; are we on a mono or EGA system (is DX = 0)?
    JZ    Mono        ; yes, skip over the retrace stuff

EVEN
CGA:
    CLI            ; prevent interrupts to speed routine
    Wait_CGA_Retrace    ; wait for CGA retrace MACRO
    Lodsb                   ; get character from TEXT$ and increment SI
    Stosw            ; store both the character and attribute
    STI            ; allow interrupts again
    Cmp     DI,3998         ; are we at last character? (80 * 25) display
    JBE    @f        ; nope
    Call    _Rollup        ; scroll up & reset to left column
@@:
    Loop    CGA        ; loop until CX is zero
    Jmp    Short  Exit1
EVEN
Mono:
    Lodsb                   ; get character from TEXT$ and increment SI
    Stosw            ; store both the character and attribute
    Cmp     DI,VPageSize    ; are we at last character?
    JBE    @f        ; nope
    Call    _Rollup        ; scroll up & reset to left column
@@:
    Loop    Mono        ; loop until CX is zero

Exit1:
    Mov    B$DVIDEODI,DI    ; store DI for the future
    Ret
QPRINTL ENDP

;===========================================================================
; DECLARE SUB VADDR (Row%, Column%)
;  CALL VADDR(Row%, Column%)
;  returns the current end of string address for the qprint routines
;===========================================================================

EVEN
VADDR PROC FAR BASIC, ROW:WORD, COLL:WORD
    Xor     DX,DX           ;clear DX
    Mov     AX,B$DVIDEODI   ;get current DI
    Mov     BX,160          ;set divisor at 160 for 80 column display
    Div     BX              ;divide AX by BX.  Row in AX, remainder in DX
    Inc     AX              ;remove zero bias
    SHR     DX,1            ;divide remainder by 2 then increment
    Inc     DX              ;to remove zero bias
    Mov     BX,ROW          ;store values
    Mov     [BX],AX
    Mov     BX,COLL
    Mov     [BX],DX
    Ret
VADDR ENDP

;=======================================================================
; _Rollup: a local routine that scrolls up the last line of a display
;          using the attribute stored in BH. If SETQP is run, then
;          is sensitive to current display length.
; Input:
;       Attribute in BH
; Preserves:
;          AX,BX,CX,DX
; Returns:
;          Screen scrolled up one line, DI reset to Last Line, Col 1
; About as fast as dedicated version below, and neatly handles snowy CGA's.
;
;=======================================================================

EVEN
_Rollup Label   Near            ;Label used so routine name will not
    Push    AX            ;be public.
    Push    BX
    Push    CX
    Push    DX
    Mov     AX,0601h            ;scroll up one row
    Xor     CX,CX               ;window at 1,1
    Mov     DH,VRow             ;put row in DH
    Mov     DL,VColumn          ;put column in DL
    Int     10h                 ; doit
    Mov     DI,VDI_Reset        ; reset DI to Last Row, Col 1
    Pop     DX
    Pop     CX
    Pop    BX
    Pop     AX
    Retn                ; routine is near!!
;end of routine

comment        |*
;=======================================================================
; _Rollup: a local routine that scrolls up the last line of a
;          80 x 25 display, using the attribute stored in BH
;          not yet corrected for snow on a CGA
;
; Input:
;          Attribute in BH, Video Segment in ES, Direction flag cleared
; Preserves:
;          AX,BX,CX,DX,DS,SI
; Returns:
;          Screen scrolled up one line, DI reset to Row 25, Col 1
;=======================================================================

_Rollup Label   Near            ;Label used so routine name will not
    Push    AX            ;be public.
    Push    CX                  ; save all registers used
    Push    SI
    Push    DS                  ; save DS
    Mov     AX,ES
    Mov     DS,AX               ; set DS == ES
    Mov     SI,160              ; copy block of 2,1 to 25,80
                    ; to 1,1 to 24,80
    Mov     CX,2000-80          ; page size in words
    Xor     DI,DI               ; destination of 1,1 (0 based)
    Rep     Movsw               ; do scroll
    Mov     CX,80               ; number of characters on bottom line
    Mov     AH,BH               ; get attribute from BH
    Mov     AL,32               ; put space character in AL
    Rep     Stosw               ; clear bottom line
    Mov     DI,3840             ; reset DI to Row 25, Col 1
    Pop     DS                  ; get back DS
    Pop     SI
    Pop     CX                  ; restore all registers used
    Pop     AX
    Retn                ; routine is near!!
;end of routine
        |*

;===========================================================================
; DECLARE SUB CLREOL ()
;    CLREOL
; Purpose:
;       Clears to end of current display line w/o changing attribute
; Assumes:
;       80 Column mode, assumes that DI has been set by SETQP; QPRINT;
;       QPRINTL; or  QPRNT
;===========================================================================

EVEN
CLREOL  PROC FAR BASIC
    Cmp     B$DVIDEOINSTL,1 ; See if we have done this before
    JE      Didit3          ; yep, so skip ahead
    Call    Get_Adapter     ; call routine to find display type

Didit3:
    Cld                     ; clear the direction flag to move data forward
    Mov     AX,B$DVIDEODI   ; get DI from last call
    Mov     DI,AX           ; set DI to reflect last call
    Xor     DX,DX           ; clear DX
    Mov     BX,160          ; set divisor at 160 for 80 column display
    Div     BX              ; divide AX by BX.  COL*2 (remainder) in DX
    SHR     DX,1            ; divide remainder by 2
    Or      DX,DX           ; if column is 1
    Jz      Exit2           ; exit as there is nothing to do
    Mov     CX,80           ; Assume in 80 column Mode
    Sub     CX,DX           ; this gives number of spaces to print

    Mov     ES,B$DVIDEOSEG  ; restore the initialized values
    Mov     DX,B$DVIDEOPORT ; puts 0 in DX if not CGA, else CGA retrace
    Mov     AL,20h          ; character to erase with (a space)
Main:
    Or      DX,DX           ; are we on a mono or EGA system (is DX = 0)?
    JZ      Mono1           ; yes, skip over the retrace stuff
    Mov     BL,AL           ; store in BL for rapid loading

EVEN
CGA1:
    CLI                     ; prevent interrupts to speed routine
    Wait_CGA_Retrace        ; wait for CGA retrace MACRO
    Mov     AL,BL           ; get character back again (MACRO destroys it)
    Stosb                   ; store the character only
    STI                     ; allow interrupts again
    Inc     DI              ; skip to next cell
    Loop    CGA1            ; loop until CX is zero
    Jmp     Short  Exit2

EVEN
Mono1:
    Stosb                   ; store the character w/o changing attribute
    Inc     DI              ; skip to next cell
    Loop    Mono1           ; loop until CX is zero

Exit2:
    Mov     B$DVIDEODI,DI   ; store DI for the future
    Ret
CLREOL  ENDP
END