;==============================================================================
;	XTA用CRC計算	in. [fhand] = file handle
;			out.bx = crc
;	セグメントの都合で32kづつ２回、読み込んで計算してます
;==============================================================================
xtcrccalc:
	mov	dx,offset buffer
	mov	cx,32*1024
	mov	bx,[fhand]
	mov	ah,3fh
	int	21h		;read

	mov	bx,-1		;crc def.
	call	calcrc
	push	bx

	mov	dx,offset buffer
	mov	cx,32*1024
	mov	bx,[fhand]
	mov	ah,3fh
	int	21h		;read

	pop	bx
	call	calcrc
	ret

;==============================================================================
;	CRC計算sub	in.bx=crc def
;==============================================================================
calcrc:	mov	si,offset buffer
	mov	di,offset crcbuf
	mov	cx,8000h	;count

crclp:	xor	dx,dx
	xchg	dh,bl	;dx=cd00
	xchg	bh,bl	;bx=00ab
	lodsb		;al=dt
	xor	bl,al	;bx=00ab xor dt
	add	bx,bx
	mov	bx,[bx+di] ;get from table [(ab xor dt)*2]
	xor	bx,dx	;bx=cd00 xor [table#]
	loop	crclp
	ret

;==============================================================================
;	CRC Data
;==============================================================================
crcbuf	dw	00000h,01021h,02042h,03063h,04084h,050A5h,060C6h,070E7h
	dw	08108h,09129h,0A14Ah,0B16Bh,0C18Ch,0D1ADh,0E1CEh,0F1EFh
	dw	01231h,00210h,03273h,02252h,052B5h,04294h,072F7h,062D6h
	dw	09339h,08318h,0B37Bh,0A35Ah,0D3BDh,0C39Ch,0F3FFh,0E3DEh
	dw	02462h,03443h,00420h,01401h,064E6h,074C7h,044A4h,05485h
	dw	0A56Ah,0B54Bh,08528h,09509h,0E5EEh,0F5CFh,0C5ACh,0D58Dh
	dw	03653h,02672h,01611h,00630h,076D7h,066F6h,05695h,046B4h
	dw	0B75Bh,0A77Ah,09719h,08738h,0F7DFh,0E7FEh,0D79Dh,0C7BCh
	dw	048C4h,058E5h,06886h,078A7h,00840h,01861h,02802h,03823h
	dw	0C9CCh,0D9EDh,0E98Eh,0F9AFh,08948h,09969h,0A90Ah,0B92Bh
	dw	05AF5h,04AD4h,07AB7h,06A96h,01A71h,00A50h,03A33h,02A12h
	dw	0DBFDh,0CBDCh,0FBBFh,0EB9Eh,09B79h,08B58h,0BB3Bh,0AB1Ah
	dw	06CA6h,07C87h,04CE4h,05CC5h,02C22h,03C03h,00C60h,01C41h
	dw	0EDAEh,0FD8Fh,0CDECh,0DDCDh,0AD2Ah,0BD0Bh,08D68h,09D49h
	dw	07E97h,06EB6h,05ED5h,04EF4h,03E13h,02E32h,01E51h,00E70h
	dw	0FF9Fh,0EFBEh,0DFDDh,0CFFCh,0BF1Bh,0AF3Ah,09F59h,08F78h
	dw	09188h,081A9h,0B1CAh,0A1EBh,0D10Ch,0C12Dh,0F14Eh,0E16Fh
	dw	01080h,000A1h,030C2h,020E3h,05004h,04025h,07046h,06067h
	dw	083B9h,09398h,0A3FBh,0B3DAh,0C33Dh,0D31Ch,0E37Fh,0F35Eh
	dw	002B1h,01290h,022F3h,032D2h,04235h,05214h,06277h,07256h
	dw	0B5EAh,0A5CBh,095A8h,08589h,0F56Eh,0E54Fh,0D52Ch,0C50Dh
	dw	034E2h,024C3h,014A0h,00481h,07466h,06447h,05424h,04405h
	dw	0A7DBh,0B7FAh,08799h,097B8h,0E75Fh,0F77Eh,0C71Dh,0D73Ch
	dw	026D3h,036F2h,00691h,016B0h,06657h,07676h,04615h,05634h
	dw	0D94Ch,0C96Dh,0F90Eh,0E92Fh,099C8h,089E9h,0B98Ah,0A9ABh
	dw	05844h,04865h,07806h,06827h,018C0h,008E1h,03882h,028A3h
	dw	0CB7Dh,0DB5Ch,0EB3Fh,0FB1Eh,08BF9h,09BD8h,0ABBBh,0BB9Ah
	dw	04A75h,05A54h,06A37h,07A16h,00AF1h,01AD0h,02AB3h,03A92h
	dw	0FD2Eh,0ED0Fh,0DD6Ch,0CD4Dh,0BDAAh,0AD8Bh,09DE8h,08DC9h
	dw	07C26h,06C07h,05C64h,04C45h,03CA2h,02C83h,01CE0h,00CC1h
	dw	0EF1Fh,0FF3Eh,0CF5Dh,0DF7Ch,0AF9Bh,0BFBAh,08FD9h,09FF8h
	dw	06E17h,07E36h,04E55h,05E74h,02E93h,03EB2h,00ED1h,01EF0h

;==============================================================================
;	Bss
;==============================================================================
fhand	dw	?
buffer	db	32*1024 dup(?)