forth: make "(parsed)" support negative literals

This limitation was becoming annoying...

forth/forth.asm

@@ -296,6 +296,8 @@ strskip:
 parseDecimal:
 	; First char is special: it has to succeed.
 	ld	a, (hl)
+	cp	'-'
+	jr	z, .negative
 	; Parse the decimal char at A and extract it's 0-9 numerical value. Put the
 	; result in A.
 	; On success, the carry flag is reset. On error, it is set.
@@ -349,6 +351,19 @@ parseDecimal:
 	cp	a	; ensure Z
 	ret
 
+.negative:
+	inc	hl
+	call	parseDecimal
+	ret	nz
+	push	hl	; --> lvl 1
+	or	a	; clear carry
+	ld	hl, 0
+	sbc	hl, de
+	ex	de, hl
+	pop	hl	; <-- lvl 1
+	xor	a	; set Z
+	ret
+
 ; *** Support routines ***
 ; Find the entry corresponding to word where (HL) points to and sets DE to
 ; point to that entry.
@@ -1313,39 +1328,9 @@ R2P:
 	push	hl
 	jp	next
 
-	.db	"I"
-	.dw	$-R2P
-	.db	1
-I:
-	.dw	nativeWord
-	ld	l, (ix)
-	ld	h, (ix+1)
-	push	hl
-	jp	next
-
-	.db	"I'"
-	.dw	$-I
-	.db	2
-IPRIME:
-	.dw	nativeWord
-	ld	l, (ix-2)
-	ld	h, (ix-1)
-	push	hl
-	jp	next
-
-	.db	"J"
-	.dw	$-IPRIME
-	.db	1
-J:
-	.dw	nativeWord
-	ld	l, (ix-4)
-	ld	h, (ix-3)
-	push	hl
-	jp	next
-
 ; ( a b -- c ) A + B
 	.db "+"
-	.dw $-J
+	.dw $-R2P
 	.db 1
 PLUS:
 	.dw nativeWord
@@ -1370,35 +1355,9 @@ MINUS:
 	push	hl
 	jp	next
 
-; ( a b -- c ) A * B
-	.db "*"
-	.dw $-MINUS
-	.db 1
-MULT:
-	.dw nativeWord
-	pop	de
-	pop	bc
-	call	chkPS
-	; DE * BC -> DE (high) and HL (low)
-	ld	hl, 0
-	ld	a, 0x10
-.loop:
-	add	hl, hl
-	rl	e
-	rl	d
-	jr	nc, .noinc
-	add	hl, bc
-	jr	nc, .noinc
-	inc	de
-.noinc:
-	dec a
-	jr	nz, .loop
-	push	hl
-	jp	next
-
 ; ( a1 a2 -- b )
 	.db "SCMP"
-	.dw $-MULT
+	.dw $-MINUS
 	.db 4
 SCMP:
 	.dw nativeWord

forth/z80a.fs

@@ -26,6 +26,12 @@
   extra 0xdd / 0xfd and then spit the equivalent of HL )
 : IX 0xdd A, HL ;
 : IY 0xfd A, HL ;
+: _ix+- 0xff AND 0xdd A, (HL) ;
+: _iy+- 0xff AND 0xfd A, (HL) ;
+: IX+ _ix+- ;
+: IX- 0 -^ _ix+- ;
+: IY+ _iy+- ;
+: IY- 0 -^ _iy+- ;
 
 ( -- )
 : OP1 CREATE C, DOES> C@ A, ;
@@ -77,17 +83,35 @@
 0x03 OP1qq INCss,
 0x09 OP1qq ADDHLss,
 
-( rd rr )
+: _1rr
-: OP1rr
-    CREATE C,
-    DOES>
     C@              ( rd rr op )
     ROT             ( rr op rd )
     8 *             ( rr op rd<<3 )
     OR OR A,
 ;
+
+( rd rr )
+: OP1rr
+    CREATE C,
+    DOES>
+    _1rr
+;
 0x40 OP1rr LDrr,
 
+( ixy+- HL rd )
+: LDIXYr,
+    ( dd/fd has already been spit )
+    LDrr,           ( ixy+- )
+    A,
+;
+
+( rd ixy+- HL )
+: LDrIXY,
+    ROT             ( ixy+- HL rd )
+    SWAP            ( ixy+- rd HL )
+    LDIXYr,
+;
+
 ( n -- )
 : OP2n
     CREATE C,

forth/z80c.fs

@@ -113,6 +113,27 @@ CODE XOR
     HL PUSHqq,
 ;CODE
 
+CODE *
+    DE POPqq,
+    BC POPqq,
+    chkPS,
+	( DE * BC -> DE (high) and HL (low) )
+    HL 0 LDddnn,
+    A 0x10 LDrn,
+( loop )
+    HL ADDHLss,
+    E RLr,
+    D RLr,
+    6 JRNCe, ( noinc )
+    BC ADDHLss,
+    3 JRNCe, ( noinc )
+    DE INCss,
+( noinc )
+    A DECr,
+    -12 JRNZe, ( loop )
+    HL PUSHqq,
+;CODE
+
 ( Borrowed from http://wikiti.brandonw.net/ )
 ( Divides AC by DE and places the quotient in AC and the
   remainder in HL )
@@ -133,7 +154,7 @@ CODE /MOD
     DE ADDHLss,
     C DECr,
 ( skip )
-    0 12 - DJNZe, ( loop )
+    -12 DJNZe, ( loop )
     B A LDrr,
     HL PUSHqq,
     BC PUSHqq,
@@ -168,3 +189,21 @@ CODE PC@
     L INr(C),
     HL PUSHqq,
 ;CODE
+
+CODE I
+    L 0 IX+ LDrIXY,
+    H 1 IX+ LDrIXY,
+    HL PUSHqq,
+;CODE
+
+CODE I'
+    L 2 IX- LDrIXY,
+    H 1 IX- LDrIXY,
+    HL PUSHqq,
+;CODE
+
+CODE J
+    L 4 IX- LDrIXY,
+    H 3 IX- LDrIXY,
+    HL PUSHqq,
+;CODE