diff --git a/CORE.F b/CORE.F
new file mode 100644
index 0000000..67607a1
--- /dev/null
+++ b/CORE.F
@@ -0,0 +1,6 @@
+\ Core words for DOS FORTH
+
+: / /MOD SWAP DROP ;
+: A 10 ;
+
+A . BYE
diff --git a/DICTNRY.ASM b/DICTNRY.ASM
index 5bb97cb..c7edce4 100644
--- a/DICTNRY.ASM
+++ b/DICTNRY.ASM
@@ -1,5 +1,5 @@
 ;;; Dictionary manipulation & memory management words
-
+	
 	;; ( addr len -- entry? )
 	DEFWORD_RAW FIND, 'FIND'
 	POP CX						; String length
@@ -20,7 +20,7 @@
 	MOV BX, WORD [BX]			; Offset 0 = *LINK
 	TEST BX, BX
 	JNZ .LOOP					; If BX is 0 (end) fall through
-	
+
 .MATCH:
 	PUSH BX						; BX holds dict entry
 	NEXT
@@ -142,7 +142,6 @@
 	DEFWORD_THREADED CREATE, 'CREATE'
 	DW HERE, GET				; ( *here )
 	DW _WORD					; ( *here *string length )
-	DW _2DUP, TYPE, SPACE		; ( *here *string length )
 	DW LATEST, GET				; ( *here *string length link )
 	DW COMMA, DUP, CHAR_COMMA	; ( *here *string length )
 	DW CMOVE_HERE				; ( *here )
@@ -354,3 +353,45 @@
 	RELATIVE_ADDRESS .LOOP
 .DONE:
 	DW CR, EXIT
+
+
+	DEFWORD_RAW SHOW_STACK, '.S'
+	MOV CX, WORD [CONST_SP_INITIAL]
+	RSPUSH SI
+	STD							; Go backwards
+
+	MOV SI, CX					; Going down
+	SUB SI, 2					; Just below it
+	SUB CX, SP					; Number of bytes on the stack
+	JLE .DONE					; Below stack bottom (oops!)
+	SHR CX, 1					; Divide by 2 -- number of cells
+
+.LOOP:
+	LODSW
+	PUSH CX						; Clobbered
+	CALL DOT_INT
+	POP CX
+
+	MOV DX, ' '
+	WRITECOUT
+
+	LOOP .LOOP
+
+.DONE:
+	MOV DX, CRLF_MSG
+	WRITESOUT
+	
+	RSPOP SI
+	CLD
+	NEXT
+
+
+	DEFWORD_THREADED DUMP_IMAGE, 'DUMP-IMAGE'
+	DW LITERAL, F_WRITE			; ( *string len flags )
+	DW OPEN_FILE				; ( handle )
+	DW DUP						; ( handle handle )
+	DW LITERAL, 100h			; ( handle handle *start )
+	DW SWAP, HERE, GET			; ( handle *start handle *here )
+	DW SWAP, FILE_WRITE_RANGE	; ( handle )
+	DW CLOSE_FILE				; ( )
+	DW EXIT
diff --git a/DOS.ASM b/DOS.ASM
index 646ac7a..ed5d2e9 100644
--- a/DOS.ASM
+++ b/DOS.ASM
@@ -32,3 +32,29 @@
 
 	%DEFINE ASCII_RETURN 0Dh
 	%DEFINE ASCII_NEWLINE 0Ah
+
+	%DEFINE F_READ 0
+	%DEFINE F_WRITE 1
+	%DEFINE F_READ_WRITE 2
+
+	;; DX - null-terminated file name
+	;; AL - flags
+	%MACRO OPENF 0
+	MOV AH, 3Dh
+	INT 21h
+	%ENDMACRO
+
+	%MACRO WRITEF 0
+	MOV AH, 40h
+	INT 21h
+	%ENDMACRO
+
+	%MACRO CLOSEF 0
+	MOV AH, 3Eh
+	INT 21h
+	%ENDMACRO
+
+	%MACRO CREATF 0
+	MOV AH, 3Ch
+	INT 21h
+	%ENDMACRO
diff --git a/FORTH.ASM b/FORTH.ASM
index 6ec3fcd..5dd77a7 100644
--- a/FORTH.ASM
+++ b/FORTH.ASM
@@ -107,11 +107,11 @@
 	%ENDMACRO
 
 
-	%MACRO DEFCONST 3
+	%MACRO DEFCONST 2
 	DEFWORD_RAW %1, %2
-	PUSH CONST_%1
+	PUSH WORD [CONST_%1]
 	NEXT
-	CONST_%1 EQU %3
+CONST_%1:
 	%ENDMACRO
 
 
@@ -135,8 +135,9 @@
 _START:
 	;; Progran begins
 	MOV BP, SP
-	SUB BP, 1024				; why can't I use SP as a base for
-								; load effective address?
+	SUB BP, 1024
+	MOV WORD [CONST_SP_INITIAL], SP
+
 	MOV SI, INDIRECT_START
 	NEXT
 
@@ -192,8 +193,7 @@
 	JMP DOT_INT
 	
 
-	;; TODO: should not be immediate, that's just for debugging
-	DEFWORD_RAW_IMMEDIATE BYE, 'BYE'
+	DEFWORD_RAW BYE, 'BYE'
 	FLUSH
 	QUIT_PROC
 
@@ -241,6 +241,23 @@
 	NEXT
 
 
+	DEFWORD_RAW SLASHMOD, '/MOD'
+	POP DX
+	POP AX
+	IDIV DX
+	PUSH DX						; Remainder
+	PUSH AX						; Quotient
+	NEXT
+
+
+	DEFWORD_RAW _TIMES, '*'
+	POP AX
+	POP DX
+	IMUL DX
+	PUSH AX
+	NEXT
+
+
 	DEFWORD_RAW AND, 'AND'
 	POP AX
 	POP DX
@@ -287,6 +304,41 @@
 	PUSH BX
 	PUSH AX
 	NEXT
+
+
+	DEFWORD_RAW TEST_WRITE_FILE, 'TEST-WRITE-FILE'
+	MOV AL, F_WRITE
+	MOV DX, DUMP
+	OPENF
+	JC .OPEN
+
+	MOV BX, AX					; Handle
+	MOV CX, 4
+	MOV DX, DUMP
+	WRITEF
+	JC .WRITE
+
+	CLOSEF
+	JC .CLOSE
+
+	NEXT
+
+.OPEN:
+	MOV DX, MSG_OPENF_FAILED
+	WRITESOUT
+	NEXT
+
+.WRITE:
+	;; 06h - invalid handle
+	PUSH AX
+	MOV DX, MSG_WRITEF_FAILED
+	WRITESOUT
+	NEXT
+
+.CLOSE:
+	MOV DX, MSG_CLOSEF_FAILED
+	WRITESOUT
+	NEXT
 	
 
 	%INCLUDE "IOWORDS.ASM"
@@ -300,6 +352,10 @@
 	DEFVAR HERE, 'HERE'
 	DW HERE_START
 
+
+	DEFCONST SP_INITIAL, 'S0'
+	DW 0
+
 	
 	;; LATEST must be the last word defined in FORTH.ASM!
 	DEFVAR LATEST, 'LATEST'
@@ -308,6 +364,11 @@
 
 ;;; PROGRAM DATA ;;;
 	MSG DB 'DOS FORTH', 0Dh, 0Ah, '$'
+	DUMP DB 'DUMP.COM', 0
+	DUMP_LEN EQU 8
+
+	MSG_CLOSEF_FAILED DB 'CLOSEF FAILED', 0Dh, 0Ah, '$'
+	MSG_WRITEF_FAILED DB 'WRITEF FAILED', 0Dh, 0Ah, '$'
 
 
 	ALIGN 4
diff --git a/IOWORDS.ASM b/IOWORDS.ASM
index d1cea38..b938137 100644
--- a/IOWORDS.ASM
+++ b/IOWORDS.ASM
@@ -18,17 +18,6 @@
 	;; This routine returns the key in AL, but Forth wants it on the
 	;; stack, so we have a helper function.
 READ_KEY:
-	GETSTDINSTATUS
-	TEST AL, AL
-	JZ .EOF
-
-	READCIN
-	XOR AH, AH					; We get the result in AL but we want
-								; the whole word to be the correct
-								; char.
-	RET
-
-.EOF:							; End of STDIN
 	;; Check if line buffer is empty
 	READCIN
 	XOR AH, AH 					; We don't care about the scan code
@@ -93,6 +82,14 @@
 	NEXT
 
 
+	DEFWORD_RAW_IMMEDIATE LPAREN, '('
+.LOOP:
+	CALL READ_KEY
+	CMP AL, ')'
+	JNE .LOOP
+	NEXT
+
+
 	;; ( string len -- num unparsed )
 	DEFWORD_RAW NUMBER, 'NUMBER'
 	POP DX						; Length
@@ -166,6 +163,8 @@
 	;; ( n -- )
 	DEFWORD_RAW DOT, '.'
 	POP AX 						; The number
+	CALL DOT_INT
+	NEXT
 
 DOT_INT:	
 	TEST AX, AX
@@ -173,7 +172,7 @@
 
 	MOV DX, '0'
 	WRITECOUT
-	NEXT
+	RET
 	
 .START:
 	MOV BX, 10					; The base
@@ -202,11 +201,85 @@
 .END:
 	LOOP .REVERSE
 
+	RET
+
+
+	;; ( flags *start len )
+	DEFWORD_RAW OPEN_FILE_NAMED, 'OPEN-FILE-NAMED'
+	POP CX						; Length
+	POP BX						; Start
+	MOV DX, BX
+	ADD BX, CX
+	MOV BYTE [BX], 0
+	POP CX						; Flags
+	CREATF
+
+	MOV AX, CX					; Flags
+	OPENF
+
+	JC FILE_WRITE_ERROR
+	PUSH AX
+	NEXT
+
+FILE_WRITE_ERROR:
+	MOV DX, MSG_OPENF_FAILED
+	WRITESOUT
+	PUSH AX
+	NEXT
+
+
+	;; ( flags -- handle )
+	DEFWORD_THREADED OPEN_FILE, 'OPEN-FILE'
+	DW _WORD					; ( flags *str len )
+	DW OPEN_FILE_NAMED
+	DW EXIT
+
+
+	DEFWORD_RAW CLOSE_FILE, 'CLOSE-FILE'
+	POP BX
+	CLOSEF
+	NEXT
+
+
+	;; Write word to file
+	;; ( cell handle -- )
+	DEFWORD_RAW FILE_COMMA, 'F,'
+	POP BX						; Handle
+	POP DX						; Data
+	MOV WORD [FILE_WRITE_BUFFER], DX
+	MOV DX, FILE_WRITE_BUFFER	; Address
+	MOV CX, 2					; Length
+	WRITEF
+	JC FILE_WRITE_ERROR
+	NEXT
+
+
+	;;  ( byte handle -- )
+	DEFWORD_RAW FILE_CHAR_COMMA, 'FC,'
+	POP BX
+	POP DX
+	MOV BYTE [FILE_WRITE_BUFFER], DL
+	MOV DX, FILE_WRITE_BUFFER
+	MOV CX, 1
+	WRITEF
+	JC FILE_WRITE_ERROR
+	NEXT
+
+
+	;; ( *start *end handle -- )
+	DEFWORD_RAW FILE_WRITE_RANGE, 'FWRITE-RANGE'
+	POP BX
+	POP CX						; End
+	POP DX
+	SUB CX, DX					; Get difference
+	WRITEF
 	NEXT
 
 
 ;;; DATA ;;;
 	CRLF_MSG DB ASCII_RETURN, ASCII_NEWLINE, '$'
+	MSG_OPENF_FAILED DB 'File error', ASCII_RETURN, ASCII_NEWLINE, '$'
 
-	WORD_BUFFER TIMES 32 DB 0
+	WORD_BUFFER TIMES 33 DB 0
+	FILE_WRITE_BUFFER DW 0
 WORD_BUFFER_END: