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Cream of the Crop 1
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Cream of the Crop 1.iso
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PROGRAM
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PIELOGO.ARJ
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PIXADDR1.INC
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1992-01-25
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854b
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51 lines
;
; this routine returns the pixel addr for ega modes
; when given x and y coords
;
; caller: ax = y-coordinate
; bx = x-cooordintat
;
; returns: ah = bit mask
; bx = byte offset in buffer
; cl = number of bits to shift left
; es = video buffer segment
;
IF (vgmode EQ 10h) OR (vgmode EQ 0dh)
pixadd macro
push dx
mov dx,bpl ; bytes per line
mul dx
mov cl,3
pop dx
mov ch,bl ; save old x low part
shr bx,cl
; add bx,vboff ; add in offset
add bx,ax ; add in y offset
mov cl,ch
and cl,7
xor cl,7
mov ax,vgseg ; load es with proper segment
mov es,ax
mov ah,1
endm
ENDIF
IF vgmode EQ 81h
pixadd macro
mov cl,bl
shr ax,1
rcr bx,1
shr ax,1
rcr bx,1
shr bx,1
mov ah,bpl
mul ah
add bx,ax
add bx,vboff
mov ax,vgseg
mov es,ax
and cl,7
xor cl,7
mov ah,1
endm
ENDIF