diff --git a/libs/master.lib/dos_read.asm b/libs/master.lib/dos_read.asm
new file mode 100644
index 00000000..be7e96ff
--- /dev/null
+++ b/libs/master.lib/dos_read.asm
@@ -0,0 +1,59 @@
+; master library module
+;
+; Description:
+;	ファイルの読み込み
+;
+; Functions/Procedures:
+;	int dos_read( int fh, void far * buffer, unsigned len ) ;
+;
+; Parameters:
+;	
+;
+; Returns:
+;	int	AccessDenied (cy=1)	失敗,読み込み禁止
+;		InvalidHandle(cy=1)	失敗,ファイルハンドルが無効
+;		else	     (cy=0)	成功,読み込んだバイト数
+;
+; Binding Target:
+;	Microsoft-C / Turbo-C / Turbo Pascal
+;
+; Running Target:
+;	PC-9801
+;
+; Requiring Resources:
+;	CPU: 8086
+;
+; Notes:
+;	
+;
+; Compiler/Assembler:
+;	TASM 3.0
+;	OPTASM 1.6
+;
+; Author:
+;	恋塚(恋塚昭彦)
+;
+; Revision History:
+;	93/ 3/17 Initial: master.lib
+;
+
+func DOS_READ
+	push	BP
+	mov	BP,SP
+	@@fh	= (RETSIZE+4)*2
+	@@buf	= (RETSIZE+2)*2
+	@@len	= (RETSIZE+1)*2
+
+	push	DS
+	mov	BX,[BP+@@fh]
+	lds	DX,[BP+@@buf]
+	mov	CX,[BP+@@len]
+	mov	AH,3fh
+	int	21h
+	pop	DS
+	jnc	short @@SUCCESS
+	neg	AX	; cy=1
+@@SUCCESS:
+	pop	BP
+	ret	8
+endfunc
diff --git a/th04_main.asm b/th04_main.asm
index e36bcddf..9a981951 100644
--- a/th04_main.asm
+++ b/th04_main.asm
@@ -865,36 +865,7 @@ sub_85E		proc far
 		retf
 sub_85E		endp
 
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_864		proc far
-
-arg_0		= word ptr  6
-arg_2		= dword	ptr  8
-arg_6		= word ptr  0Ch
-
-		push	bp
-		mov	bp, sp
-		push	ds
-		mov	bx, [bp+arg_6]
-		lds	dx, [bp+arg_2]
-		mov	cx, [bp+arg_0]
-		mov	ah, 3Fh
-		int	21h		; DOS -	2+ - READ FROM FILE WITH HANDLE
-					; BX = file handle, CX = number	of bytes to read
-					; DS:DX	-> buffer
-		pop	ds
-		jnb	short loc_87A
-		neg	ax
-
-loc_87A:
-		pop	bp
-		retf	8
-sub_864		endp
-
+include libs/master.lib/dos_read.asm
 include libs/master.lib/dos_seek.asm
 
 ; =============== S U B	R O U T	I N E =======================================
@@ -6930,9 +6901,7 @@ loc_389E:
 		push	ax
 		push	cx
 		push	di
-		nop
-		push	cs
-		call	near ptr sub_864
+		nopcall	dos_read
 		mov	es, [bp+var_2]
 		mov	bx, ax
 		mov	byte ptr es:[bx], 0FFh
diff --git a/th04_maine.asm b/th04_maine.asm
index 956e15c0..4e2de2d1 100644
--- a/th04_maine.asm
+++ b/th04_maine.asm
@@ -783,36 +783,7 @@ sub_7EA		proc far
 		retf
 sub_7EA		endp
 
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_7F0		proc far
-
-arg_0		= word ptr  6
-arg_2		= dword	ptr  8
-arg_6		= word ptr  0Ch
-
-		push	bp
-		mov	bp, sp
-		push	ds
-		mov	bx, [bp+arg_6]
-		lds	dx, [bp+arg_2]
-		mov	cx, [bp+arg_0]
-		mov	ah, 3Fh
-		int	21h		; DOS -	2+ - READ FROM FILE WITH HANDLE
-					; BX = file handle, CX = number	of bytes to read
-					; DS:DX	-> buffer
-		pop	ds
-		jnb	short loc_806
-		neg	ax
-
-loc_806:
-		pop	bp
-		retf	8
-sub_7F0		endp
-
+include libs/master.lib/dos_read.asm
 include libs/master.lib/dos_seek.asm
 
 ; =============== S U B	R O U T	I N E =======================================
@@ -4055,9 +4026,7 @@ loc_2EBA:
 		push	ax
 		push	cx
 		push	di
-		nop
-		push	cs
-		call	near ptr sub_7F0
+		nopcall	dos_read
 		mov	es, [bp+var_2]
 		mov	bx, ax
 		mov	byte ptr es:[bx], 0FFh
diff --git a/th04_op.asm b/th04_op.asm
index fe1cd2f5..30dafc65 100644
--- a/th04_op.asm
+++ b/th04_op.asm
@@ -769,38 +769,7 @@ loc_7DB:
 		retf	4
 sub_7B8		endp
 
-; ---------------------------------------------------------------------------
-		nop
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_7E2		proc far
-
-arg_0		= word ptr  6
-arg_2		= dword	ptr  8
-arg_6		= word ptr  0Ch
-
-		push	bp
-		mov	bp, sp
-		push	ds
-		mov	bx, [bp+arg_6]
-		lds	dx, [bp+arg_2]
-		mov	cx, [bp+arg_0]
-		mov	ah, 3Fh
-		int	21h		; DOS -	2+ - READ FROM FILE WITH HANDLE
-					; BX = file handle, CX = number	of bytes to read
-					; DS:DX	-> buffer
-		pop	ds
-		jnb	short loc_7F8
-		neg	ax
-
-loc_7F8:
-		pop	bp
-		retf	8
-sub_7E2		endp
-
+include libs/master.lib/dos_read.asm
 include libs/master.lib/dos_seek.asm
 
 ; =============== S U B	R O U T	I N E =======================================
@@ -4901,9 +4870,7 @@ loc_3658:
 		push	ax
 		push	cx
 		push	di
-		nop
-		push	cs
-		call	near ptr sub_7E2
+		nopcall	dos_read
 		mov	es, [bp+var_2]
 		mov	bx, ax
 		mov	byte ptr es:[bx], 0FFh
diff --git a/th05_main.asm b/th05_main.asm
index f570b709..3079dbd7 100644
--- a/th05_main.asm
+++ b/th05_main.asm
@@ -770,36 +770,7 @@ sub_7EC		proc far
 		retf
 sub_7EC		endp
 
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_7F2		proc far
-
-arg_0		= word ptr  6
-arg_2		= dword	ptr  8
-arg_6		= word ptr  0Ch
-
-		push	bp
-		mov	bp, sp
-		push	ds
-		mov	bx, [bp+arg_6]
-		lds	dx, [bp+arg_2]
-		mov	cx, [bp+arg_0]
-		mov	ah, 3Fh
-		int	21h		; DOS -	2+ - READ FROM FILE WITH HANDLE
-					; BX = file handle, CX = number	of bytes to read
-					; DS:DX	-> buffer
-		pop	ds
-		jnb	short loc_808
-		neg	ax
-
-loc_808:
-		pop	bp
-		retf	8
-sub_7F2		endp
-
+include libs/master.lib/dos_read.asm
 include libs/master.lib/dos_seek.asm
 
 ; =============== S U B	R O U T	I N E =======================================
@@ -6779,9 +6750,7 @@ loc_3838:
 		push	ax
 		push	cx
 		push	di
-		nop
-		push	cs
-		call	near ptr sub_7F2
+		nopcall	dos_read
 		mov	es, [bp+var_2]
 		mov	bx, ax
 		mov	byte ptr es:[bx], 0FFh
diff --git a/th05_maine.asm b/th05_maine.asm
index 6ff2518a..eb616d19 100644
--- a/th05_maine.asm
+++ b/th05_maine.asm
@@ -757,36 +757,7 @@ sub_7C8		proc far
 		retf
 sub_7C8		endp
 
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_7CE		proc far
-
-arg_0		= word ptr  6
-arg_2		= dword	ptr  8
-arg_6		= word ptr  0Ch
-
-		push	bp
-		mov	bp, sp
-		push	ds
-		mov	bx, [bp+arg_6]
-		lds	dx, [bp+arg_2]
-		mov	cx, [bp+arg_0]
-		mov	ah, 3Fh
-		int	21h		; DOS -	2+ - READ FROM FILE WITH HANDLE
-					; BX = file handle, CX = number	of bytes to read
-					; DS:DX	-> buffer
-		pop	ds
-		jnb	short loc_7E4
-		neg	ax
-
-loc_7E4:
-		pop	bp
-		retf	8
-sub_7CE		endp
-
+include libs/master.lib/dos_read.asm
 include libs/master.lib/dos_seek.asm
 
 ; =============== S U B	R O U T	I N E =======================================
@@ -4466,9 +4437,7 @@ loc_3040:
 		push	ax
 		push	cx
 		push	di
-		nop
-		push	cs
-		call	near ptr sub_7CE
+		nopcall	dos_read
 		mov	es, [bp+var_2]
 		mov	bx, ax
 		mov	byte ptr es:[bx], 0FFh
diff --git a/th05_op.asm b/th05_op.asm
index 065bd852..b399a5e8 100644
--- a/th05_op.asm
+++ b/th05_op.asm
@@ -749,38 +749,7 @@ loc_7B9:
 		retf	4
 sub_796		endp
 
-; ---------------------------------------------------------------------------
-		nop
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_7C0		proc far
-
-arg_0		= word ptr  6
-arg_2		= dword	ptr  8
-arg_6		= word ptr  0Ch
-
-		push	bp
-		mov	bp, sp
-		push	ds
-		mov	bx, [bp+arg_6]
-		lds	dx, [bp+arg_2]
-		mov	cx, [bp+arg_0]
-		mov	ah, 3Fh
-		int	21h		; DOS -	2+ - READ FROM FILE WITH HANDLE
-					; BX = file handle, CX = number	of bytes to read
-					; DS:DX	-> buffer
-		pop	ds
-		jnb	short loc_7D6
-		neg	ax
-
-loc_7D6:
-		pop	bp
-		retf	8
-sub_7C0		endp
-
+include libs/master.lib/dos_read.asm
 include libs/master.lib/dos_seek.asm
 
 ; =============== S U B	R O U T	I N E =======================================
@@ -3984,9 +3953,7 @@ loc_2E78:
 		push	ax
 		push	cx
 		push	di
-		nop
-		push	cs
-		call	near ptr sub_7C0
+		nopcall	dos_read
 		mov	es, [bp+var_2]
 		mov	bx, ax
 		mov	byte ptr es:[bx], 0FFh