IFDEF ??version   ; EAN
MASM51
QUIRKS
ENDIF

.model medium, c

.DATA

XDOTS	     =	     0
YDOTS	     =	     1	SHL 1
ASP_RATIO    =	     2	SHL 1
DEPTH	     =	     4	SHL 1
TPAGE	     =	     5	SHL 1
BOTBANK      =	     7	SHL 1
TOPBANK      =	     8	SHL 1
ZOOM	     =	     10 SHL 1
DISPMODE     =	     11 SHL 1
DAC567DATA   =	     15 SHL 1
TOP	     =	     51 SHL 1
BOT	     =	     53 SHL 1
VPAN	     =	     55 SHL 1
NOT_INT      =	     56 SHL 1
HIRES	     =	     61 SHL 1
PERM	     =	     64 SHL 1
BYCAP	     =	     68 SHL 1
PE	     =	     69 SHL 1
OVLE	     =	     70 SHL 1
HPAN	     =	     71 SHL 1
MEM_BASE     =	     73 SHL 1
MEM_MAP      =	     74 SHL 1
LIVEMIXSRC   =	     91 SHL 1
RGB	     =	     93 SHL 1
SVIDEO	     =	     97 SHL 1
BUFFPORTSRC  =	     98 SHL 1
CM1	     =	     101 SHL 1
CM2	     =	     102 SHL 1
LUTBYPASS    =	     107 SHL 1
CM3	     =	     113 SHL 1
LIVEPORTSRC  =	     115 SHL 1
LIVE8	     =	     116 SHL 1
VGASRC	     =	     123 SHL 1

BOARD	 STRUC
   ThisBoard	  dw	?
   ClearScreen	  dw	?
   Screen	  dd	?
   VerPan	  dw	?
   HorPan	  dw	?
   Top		  dw	?
   Bottom	  dw	?
   xdots	  dw	?
   ydots	  dw	?
   Bank64k	  dw	?
   RowBytes	  dw	?
   RowsPerBank	  dw	?
   Reg		  dw	128 DUP (?)
   Plot 	  dd	?
   GetColor	  dd	?
      rVIDSTAT	dw    ?
      rCTL	dw    ?
      rMASKL	dw    ?
      rLBNK	dw    ?
      rREADAD	dw    ?
      rMODE1	dw    ?
      rOVSTRT	dw    ?
      rUSCAN	dw    ?
      rMASKH	dw    ?
      rOSCAN	dw    ?
      rHBNK	dw    ?
      rROWCNT	dw    ?
      rMODE2	dw    ?
      rRBL	dw    ?
      rRBH	dw    ?
      wCOLOR0	dw    ?
      wCOLOR1	dw    ?
      wCOLOR2	dw    ?
      wCOLOR3	dw    ?
      wVIDCON	dw    ?
      wINDIRECT dw    ?
      wHUESAT	dw    ?
      wOVSTRT	dw    ?
      wMASKL	dw    ?
      wMASKH	dw    ?
      wLBNK	dw    ?
      wHBNK	dw    ?
      wMODE1	dw    ?
      wMODE2	dw    ?
      wWBL	dw    ?
      wWBH	dw    ?
BOARD	 ENDS

.FARDATA

extrn TPlus:WORD

.CODE

ReadTPlusBankedPixel	  PROC	   uses si di es ds, x:WORD, y:WORD
   mov	 ax, SEG TPlus
   mov	 ds, ax
   mov	 di, OFFSET TPlus
   mov	 bx, [di].Reg[YDOTS]
   dec	 bx
   sub	 bx, y
   mov	 ax, [di].Reg[TPAGE]
   mov	 cl, 9
   shl	 ax, cl
   add	 bx, ax
   mov	 si, bx

   mov	 cx, 16
   sub	 cx, [di].RowBytes
   shr	 si, cl
   cmp	 si, [di].Bank64k
   je	 CorrectBank

   mov	 [di].Bank64k, si
   mov	 ax, si
   shl	 ax, 1
   mov	 dx, [di].wLBNK
   mov	 ah, al
   inc	 ah
   out	 dx, ax

CorrectBank:
   mov	 cx, [di].RowsPerBank
   shl	 si, cl
   sub	 bx, si
   mov	 cx, [di].RowBytes
   shl	 bx, cl
   mov	 ax, WORD PTR [[di].Screen+2]
   mov	 es, ax
   mov	 cx, [di].Reg[DEPTH]
   dec	 cx
   jnz	 CheckDepth2

   add	 bx, x
   mov	 al, es:[bx]
   xor	 ah, ah
   jmp	 ExitPlotBankedPixel

CheckDepth2:
   dec	 cx
   jnz	 Read4Bytes

   mov	 cx, x
   shl	 cx, 1
   add	 bx, cx
   mov	 ax, es:[bx]

   mov   dx, ax
   mov   cl, 10
   shr   dx, cl
   mov   cl, 3
   shl   dx, cl
   shl   ax, cl
   shl   ah, cl

   jmp	 ExitPlotBankedPixel

Read4Bytes:
   mov	 cx, x
   shl	 cx, 1
   shl	 cx, 1
   add	 bx, cx
   mov	 ax, es:[bx]
   mov	 dx, es:[bx+2]

ExitPlotBankedPixel:
   ret
ReadTPlusBankedPixel	  ENDP



WriteTPlusBankedPixel	   PROC     uses si di es ds, x:WORD, y:WORD, Color:WORD
   mov	 ax, SEG TPlus
   mov	 ds, ax
   mov	 di, OFFSET TPlus
   mov	 bx, [di].Reg[YDOTS]
   dec	 bx
   sub	 bx, y
   mov	 ax, [di].Reg[TPAGE]
   mov	 cl, 9
   shl	 ax, cl
   add	 bx, ax
   mov	 si, bx

   mov	 cx, 16
   sub	 cx, [di].RowBytes
   shr	 si, cl
   cmp	 si, [di].Bank64k
   je	 CorrectBank

   mov	 [di].Bank64k, si
   mov	 ax, si
   shl	 ax, 1
   mov	 dx, [di].wLBNK
   mov	 ah, al
   inc	 ah
   out	 dx, ax

CorrectBank:
   mov	 cx, [di].RowsPerBank
   shl	 si, cl
   sub	 bx, si
   mov	 cx, [di].RowBytes
   shl	 bx, cl
   mov	 ax, WORD PTR [[di].Screen+2]
   mov	 es, ax
   mov	 cx, [di].Reg[DEPTH]
   dec	 cx
   jnz	 CheckDepth2

   mov	 ax, Color
   add	 bx, x
   mov	 es:[bx], al
   jmp	 ExitPlotBankedPixel

CheckDepth2:
   dec	 cx
   jnz	 Write4Bytes

   mov	 ax, Color
   mov   cl, 3
   shr   ah, cl
   shr   ax, cl
   mov   dx, Color+2
   shr   dx, cl
   mov   cx, 10
   shl   dx, cl
   or    ax, dx

   mov	 cx, x
   shl	 cx, 1
   add	 bx, cx
   mov	 es:[bx], ax
   jmp	 ExitPlotBankedPixel

Write4Bytes:
   mov	 ax, Color
   mov	 cx, x
   shl	 cx, 1
   shl	 cx, 1
   add	 bx, cx
   mov	 es:[bx], ax
   mov	 ax, Color+2
   mov	 es:[bx+2], ax

ExitPlotBankedPixel:
   ret
WriteTPlusBankedPixel	   ENDP



END