Conditional jumps work now.

Holy shit that was a hairy debug session.  I have a lot to look
forward to.

5 files changed, 41 insertions, 17 deletions

diff --git a/Makefile b/Makefile
index e5a4ad6..45601d9 100644
--- a/Makefile
+++ b/Makefile
@@ -26,5 +26,5 @@ testbenches/mine.h:	testbenches/mine.bin
 	hexdump -v -e '12/1 "0x%02x, "' -e '"\n"' testbenches/mine.bin | sed -e 's/0x *,//g' >> testbenches/mine.h
 	echo '};' >> testbenches/mine.h
 
-testbenches/zexdoc.bin:	testbenches/mine.z80
+testbenches/mine.bin:	testbenches/mine.z80
 	spasm testbenches/mine.z80
diff --git a/alu.asm b/alu.asm
index 5eb79de..3432938 100644
--- a/alu.asm
+++ b/alu.asm
@@ -86,6 +86,6 @@ alu_cp:
 	move.b	#1,f_tmp_byte
 	andi.b	#%00000010,flag_valid
 	move.b	#%00000010,flag_byte
-	sub	d0,d1
+	sub.b	d0,d1
 	move	sr,f_host_sr
 	rts
diff --git a/flags.asm b/flags.asm
index 40e2f44..0377108 100644
--- a/flags.asm
+++ b/flags.asm
@@ -44,7 +44,9 @@ F_ADD_SAVE	MACRO
 	F_SET	#%
 	ENDM
 
-	;; Normalize and return carry bit (is loaded into Z bit)
+	;; Normalize and return inverse of emulated Carry bit (loaded
+	;; into host zero flag)
+
 	;; Destroys d1
 f_norm_c:
 	move.b	flag_valid-flag_storage(a3),d1
@@ -60,7 +62,9 @@ FNC_ok:
 	andi.b	#%00000001,d1
 	rts
 
-	;; Normalize and return zero bit (loaded into Z bit)
+	;; Normalize and return inverse of emulated Zero bit (loaded
+	;; into host zero flag)
+
 	;; Destroys d1
 f_norm_z:
 	move.b	flag_valid-flag_storage(a3),d1
@@ -72,8 +76,9 @@ FNZ_ok:
 	andi.b	#%01000000,d1
 	rts
 
-	;; Normalize and return Parity/oVerflow bit (loaded into Z
-	;; bit)
+	;; Normalize and return inverse of emulated Parity/oVerflow
+	;; bit (loaded into host zero flag)
+
 	;; Destroys d1
 f_norm_pv:
 	move.b	flag_valid-flag_storage(a3),d1
@@ -160,7 +165,9 @@ f_cc_byte:
 	popm	d2-d5
 	rts
 
-	;; Normalize and return Sign bit (loaded into Z bit).
+	;; Normalize and return inverse of emulated Sign bit (loaded
+	;; into host zero flag).
+
 	;; Destroys d1
 f_norm_sign:
 	move.b	flag_valid-flag_storage(a3),d1
diff --git a/opcodes.asm b/opcodes.asm
index 7568c49..b96af7b 100644
--- a/opcodes.asm
+++ b/opcodes.asm
@@ -415,7 +415,7 @@ emu_op_18:
 	FETCHBI	d1
 	move.l	epc,a0
 	bsr	underef
-	add.w	d1,d0		; ??? Can I avoid underef/deref cycle?
+	add.w	d0,d1		; ??? Can I avoid underef/deref cycle?
 	bsr	deref
 	move.l	a0,epc
 	DONE			;nok
@@ -479,7 +479,8 @@ emu_op_20:
 	;;  PC <- PC+immed.b
 	;; No flags
 	bsr	f_norm_z
-	bne	emu_op_18	; branch taken: zero clear
+	;; if the emulated Z flag is set, this will be clear
+	beq	emu_op_18	; branch taken: Z reset -> eq (zero set)
 	add.l	#1,epc
 	DONE			;nok
 
@@ -674,10 +675,10 @@ emu_op_37:
 	;; SCF
 	;; Set Carry Flag
 	;; XXX flags are more complicated than this :(
-	move.b	#%00111011,flag_valid-flag_storage(a3)
+	ori.b	#%00111011,flag_valid-flag_storage(a3)
 	move.b	eaf,d1
 	ori.b	#%00000001,d1
-	andi.b	#%00101001,d1
+	andi.b	#%11101101,d1
 	or.b	d1,flag_byte-flag_storage(a3)
 	DONE			;nok
 
@@ -1734,7 +1735,7 @@ F_CP_B	MACRO
 	START
 emu_op_b8:
 	;; CP	B
-	move.b	ebc,d2
+	move.w	ebc,d2
 	LOHI	d2
 	F_CP_B	d2,eaf
 	DONE			;nok
@@ -1748,7 +1749,7 @@ emu_op_b9:
 	START
 emu_op_ba:
 	;; CP	D
-	move.b	ede,d2
+	move.w	ede,d2
 	LOHI	d2
 	F_CP_B	d2,eaf
 	DONE			;nok
@@ -1762,7 +1763,7 @@ emu_op_bb:
 	START
 emu_op_bc:
 	;; CP	H
-	move.b	ehl,d2
+	move.w	ehl,d2
 	LOHI	d2
 	F_CP_B	d2,eaf
 	DONE			;nok
diff --git a/testbenches/mine.z80 b/testbenches/mine.z80
index aa33fb5..57c6998 100644
--- a/testbenches/mine.z80
+++ b/testbenches/mine.z80
@@ -3,7 +3,7 @@
 
 .ORG 4000h
 
-	call	cond_jr		;cd
+	call	cond_jr_no	;cd
 	halt			;76
 
 inc8:
@@ -19,7 +19,8 @@ dec8:
 	dec	a		;3d
 	ret			;c9
 
-cond_jr:
+	;; Test jump-not-taken of JR [C,NC,Z]
+cond_jr_no:
 	ld	a,01h		;3e 01
 	cp	a		;bf
 	jr	nz,wrong	;20 07
@@ -31,10 +32,25 @@ cond_jr:
 	jr	nc,wrong	;30 
 	ret			;c9
 
-
 wrong:
 	jp	wrong
 
+	;; Test jump-taken of JR [C,NC,Z]
+cond_jr_yes:
+	ld	a,01h		;3e 01
+	ld	b,02h		;06 02
+	cp	b		;b8
+	jr	nz,right1	;20
+	jp	wrong
+right1:	scf			;37
+	jr	c,right2	;38 
+	jp	wrong
+right2:	ccf			;3f
+	jr	nc,right3	;30 
+	jp	wrong
+right3:	ret			;c9
+
+
 data8:
 	.db	0a5h
 data16: