forth: add +-*/

apps/forth/dict.asm

@@ -248,3 +248,53 @@ FETCH:
 	call	intoHL
 	push	hl
 	jp	exit
+
+; ( a b -- c ) A + B
+PLUS:
+	.db "+"
+	.fill 7
+	.dw FETCH
+	.dw nativeWord
+	pop	hl
+	pop	de
+	add	hl, de
+	push	hl
+	jp	exit
+
+; ( a b -- c ) A - B
+MINUS:
+	.db "-"
+	.fill 7
+	.dw PLUS
+	.dw nativeWord
+	pop	de		; B
+	pop	hl		; A
+	or	a		; reset carry
+	sbc	hl, de
+	push	hl
+	jp	exit
+
+; ( a b -- c ) A * B
+MULT:
+	.db "*"
+	.fill 7
+	.dw MINUS
+	.dw nativeWord
+	pop	de
+	pop	bc
+	call	multDEBC
+	push	hl
+	jp	exit
+
+; ( a b -- c ) A / B
+DIV:
+	.db "/"
+	.fill 7
+	.dw MULT
+	.dw nativeWord
+	pop	de
+	pop	hl
+	call	divide
+	push	bc
+	jp	exit
+

apps/forth/dictionary.txt

@@ -6,6 +6,10 @@ Stack notation: "<stack before> -- <stack after>". Rightmost is top of stack
 .           n --            Print n in its decimal form
 @           a -- n          Set n to value at address a
 !           n a --          Store n in address a
++           a b -- c        a + b -> c
+-           a b -- c        a - b -> c
+*           a b -- c        a * b -> c
+/           a b -- c        a / b -> c
 CREATE x    --              Create cell named x
 EMIT        c --            Spit char c to stdout
 EXECUTE     a --            Execute word at addr a

apps/forth/main.asm

@@ -48,7 +48,7 @@ CHKEND:
 
 forthMain:
 	ld	(INITIAL_SP), sp
-	ld	hl, FETCH		; last entry in hardcoded dict
+	ld	hl, DIV		; last entry in hardcoded dict
 	ld	(CURRENT), hl
 	ld	hl, FORTH_RAMEND
 	ld	(HERE), hl