diff --git a/6.out b/6.out
new file mode 100755
index 0000000..d104972
Binary files /dev/null and b/6.out differ
diff --git a/a.out b/a.out
new file mode 100644
index 0000000..64791c5
Binary files /dev/null and b/a.out differ
diff --git a/cpu.6 b/cpu.6
new file mode 100644
index 0000000..361a8cb
Binary files /dev/null and b/cpu.6 differ
diff --git a/cpu.c b/cpu.c
index 9e5c139..b0b6bd9 100644
--- a/cpu.c
+++ b/cpu.c
@@ -219,7 +219,7 @@ step(void)
 	cpc = pc;
 	op = fetch8();
 	if(trace)
-		print("%02x %08b %08b %08b %08b %04x %02x\n",
+		print("%02x %02x %02x %02x %08b %04x %02x\n",
 			op, rA, rX, rY, rP, cpc, rS);
 	switch(op){
 	case 0x00:
@@ -713,8 +713,5 @@ step(void)
 	default:
 		print("unimplemented %#02x\n", op);
 		exits(nil);
-	case 0xFF:
-		print("%s\n", (s8int*)mem+0x500);
-		exits(nil);
 	}
 }
diff --git a/fns.h b/fns.h
index 1fec11e..72fa083 100644
--- a/fns.h
+++ b/fns.h
@@ -9,4 +9,5 @@ extern u16int	pop16(void);
 extern u8int	fetch8(void);
 extern u16int	fetch16(void);
 
-extern void	out(void);
+extern void	in(void*);
+extern void	out(void*);
diff --git a/in.6 b/in.6
new file mode 100644
index 0000000..630b7d5
Binary files /dev/null and b/in.6 differ
diff --git a/in.c b/in.c
new file mode 100644
index 0000000..e6d6a34
--- /dev/null
+++ b/in.c
@@ -0,0 +1,22 @@
+#include <u.h>
+#include <libc.h>
+#include <ctype.h>
+#include "dat.h"
+#include "fns.h"
+
+void
+in(void*)
+{
+	int c;
+
+	for(;;){
+		if(memread(0x7005) == 1){
+			memwrite(0x7004, 1);
+			read(0, &c, 1);
+			c = toupper(c);
+			memwrite(0x7003, c);
+			memwrite(0x7004, 0);
+			memwrite(0x7005, 0);
+		}
+	}
+}
diff --git a/main.6 b/main.6
new file mode 100644
index 0000000..9df8dad
Binary files /dev/null and b/main.6 differ
diff --git a/main.c b/main.c
index d0d4365..9244fa4 100644
--- a/main.c
+++ b/main.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <libc.h>
+#include <thread.h>
 #include "dat.h"
 #include "fns.h"
 
@@ -35,7 +36,7 @@ openprog(char *f)
 }
 
 void
-main(int argc, char **argv)
+threadmain(int argc, char **argv)
 {
 	int c;
 	vlong t, t2, t3;
@@ -60,9 +61,12 @@ main(int argc, char **argv)
 	if(!argc)
 		usage();
 	openprog(*argv);
+	rS = 0xFF;
 	rP = 0x34;
 	pc = 0xFFFC;
 	pc = fetch16();
+	threadcreate(in, nil, mainstacksize);
+	threadcreate(out, nil, mainstacksize);
 	for(;;){
 		c = step();
 		while(c >= 0){
@@ -75,7 +79,6 @@ main(int argc, char **argv)
 				t3 = t2-t;
 			}
 		}
-		out();
 	}
 }
 
diff --git a/mem.6 b/mem.6
new file mode 100644
index 0000000..9015a8e
Binary files /dev/null and b/mem.6 differ
diff --git a/mkfile b/mkfile
index 6b7c155..24a7edd 100755
--- a/mkfile
+++ b/mkfile
@@ -3,7 +3,7 @@
 BIN=/$objtype/bin
 
 TARG=scemu
-OFILES=main.$O cpu.$O mem.$O out.$O
+OFILES=main.$O cpu.$O mem.$O in.$O out.$O
 UPDATE=mkfile prog.s ${OFILES:%.$O=%.c}
 
 default:V:	$O.out
diff --git a/out.6 b/out.6
new file mode 100644
index 0000000..de3077d
Binary files /dev/null and b/out.6 differ
diff --git a/out.c b/out.c
index 2c5570d..8f9489c 100644
--- a/out.c
+++ b/out.c
@@ -4,14 +4,16 @@
 #include "fns.h"
 
 void
-out(void)
+out(void*)
 {
 	int c;
 
-	if(memread(0x7002) == 1){
-		c = memread(0x7000);
-		memwrite(0x7001, 0);
-		print("%c", c);
-		memwrite(0x7001, 1);
-	}
+	for(;;)
+		if(memread(0x7002) == 1){ /* ready to be fiddled */
+			memwrite(0x7001, 1); /* we are busy */
+			c = memread(0x7000);
+			print("%c", c);
+			memwrite(0x7002, 0);
+			memwrite(0x7001, 0);
+		}
 }
diff --git a/test.s b/test.s
new file mode 100644
index 0000000..caeddbe
--- /dev/null
+++ b/test.s
@@ -0,0 +1,24 @@
+	.org $8000
+reset:
+	lda #$01
+	sta $7005
+loop:
+	lda $7004
+	bne loop
+	lda $7003
+	sta $7000
+	lda #$01
+	sta $7002
+waiting:
+	nop
+	nop
+	nop
+	nop
+	lda $7001
+	bne waiting
+	.byte $ff
+
+	.org $fffa
+	.word $8000
+	.word $8000
+	.word $8000
diff --git a/wozmon.s b/wozmon.s
new file mode 100644
index 0000000..789e0ed
--- /dev/null
+++ b/wozmon.s
@@ -0,0 +1,97 @@
+xaml = $24
+xamh = $25
+l = $28
+h = $29
+ysav = $2a
+mode = $2b
+asav = $2c
+curchar = $2d
+
+	.org $fe00
+reset:
+	cld
+	cli
+	lda #$03
+notcr:
+	cmp #$03	; is etx, subst. for esc
+	beq escape
+	iny
+	bpl nextchar
+escape:
+	lda #$5c
+	jsr echo
+getline:
+	lda #$0a
+	jsr echo
+setstor:
+	asl
+setmode:
+	sta mode
+blskip:
+nextchar:
+	ldy #1
+	sty $7005
+nextcharl:
+	lda $7004	; have next char?
+	beq nextcharl
+	lda $7003
+	sta curchar
+	cmp #$2e	; .
+	bcc blskip
+	beq setmode
+	cmp #$3a	; :
+	beq setstor
+	cmp #$52	; R
+	beq run
+	stx l
+	stx h
+	sty ysav
+nexthex:
+	lda curchar
+	eor #$b0
+	cmp #$0a
+	bcc dig
+	adc #$b9
+	cmp #$fa
+	bcc nothex
+dig:
+	asl
+	asl
+	asl
+	asl
+	ldx #$04
+hexshift:
+	asl
+	rol l
+	rol h
+	dex
+	bne hexshift
+	bne nexthex
+nothex:
+	cpy ysav
+	beq escape
+	bit mode
+	jmp nextchar
+run:
+	jmp (xaml)
+echo:
+	sta asav
+	txa
+	pha
+	lda asav
+	tax
+echol:
+	lda $7001
+	cmp #$01
+	beq echol
+	stx $7000
+	lda #$01
+	sta $7002
+	pla
+	tax
+	rts
+
+	.org $fffa
+	.word $f000
+	.word reset
+	.word $0000