diff --git a/disk/save/Makefile b/disk/save/Makefile
new file mode 100644
index 00000000..f81ef00c
--- /dev/null
+++ b/disk/save/Makefile
@@ -0,0 +1,27 @@
+include ../../Makefile.inc
+
+DOS33 = ../../utils/dos33fs-utils/dos33
+DOS33_RAW = ../../utils/dos33fs-utils/dos33_raw
+PNG_TO_40x96 = ../../utils/gr-utils/png_to_40x96
+PNG_TO_40x48D = ../../utils/gr-utils/png_to_40x48d
+PNG2RLE = ../../utils/gr-utils/png2rle
+B2D = ../../utils/bmp2dhr/b2d
+
+all:	test_write.dsk
+
+test_write.dsk:	WRITE
+	cp empty.dsk test_write.dsk
+	$(DOS33) -y test_write.dsk BSAVE -a 0x800 WRITE
+
+###
+
+WRITE:	test_write.o
+	ld65 -o WRITE test_write.o -C ../../linker_scripts/apple2_800.inc
+
+test_write.o:	test_write.s qkumba_popwr.s
+	ca65 -o test_write.o test_write.s -l test_write.lst
+
+####
+
+clean:		
+	rm -f *~ *.o *.lst WRITE
diff --git a/disk/save/empty.dsk b/disk/save/empty.dsk
new file mode 100644
index 00000000..b34eb519
Binary files /dev/null and b/disk/save/empty.dsk differ
diff --git a/disk/save/qkumba_popwr.s b/disk/save/qkumba_popwr.s
new file mode 100644
index 00000000..15430c32
--- /dev/null
+++ b/disk/save/qkumba_popwr.s
@@ -0,0 +1,236 @@
+; popwr -- code provided by qkumba
+
+tmpsec	=	$3c	; constant from boot prom
+
+
+frombuff=$d00		; sector data to write
+
+; note these must be contiguous
+encbuf=$e00		; nibble buffer must be page aligned
+bit2tbl=$f00		; in loader.s
+
+
+	;================================
+	; set up the self-modifying code
+	; to point to the proper slot
+	;================================
+	; slot number is in high nibble of A
+popwr_init:
+	lda	#$60
+
+	and	#$70		; the slot number is in the top here
+	sta	slotpatchw1+1	; self modify the code
+	sta	slotpatchw2+1
+	sta	slotpatchw3+1
+	sta	slotpatchw4+1
+
+	rts
+
+
+	;================================
+	; write a sector
+	;================================
+
+sector_write:
+
+	; convert the input to nibbles
+
+	ldy	#2			; why start at 2?
+aa:
+	ldx	#$aa
+b1:
+	dey
+frombuff_smc:
+	lda	frombuff, y
+	lsr
+	rol	bit2tbl-$aa, x
+	lsr
+	rol	bit2tbl-$aa, x
+	sta	encbuf, y
+	lda	bit2tbl-$aa, x
+	and	#$3f
+	sta	bit2tbl-$aa, x
+        inx
+        bne     b1
+        tya
+        bne     aa
+
+	; look for the proper sector to write
+
+cmpsecwr:
+b2:
+	jsr	readd5aa	; look for d5:aa marker
+	cmp	#$96		; d5:aa:96 means start of address field
+	bne	b2
+
+	ldy	#3		; try getting the sector number
+b3:
+	jsr	readnib
+	rol
+	sta	tmpsec
+	jsr	readnib
+	and	tmpsec		; and with prev nibble?
+	dey
+	bne	b3
+
+
+requested_sector:
+	cmp	#$d1
+
+	; at this point A has the sector number
+	; this code assumes you want sector 0
+
+
+	bne	cmpsecwr	; retry if not what we want?
+
+        ;skip tail #$DE #$AA #$EB some #$FFs ...
+
+	ldy	#$24
+b4:
+	dey
+	bpl     b4
+
+
+	; c0e0	slot 6 ph0 off
+	; c0e1	slot 6 ph0 on
+	; c0e2	slot 6 ph1 off
+	; c0e3	slot 6 ph1 on
+	; c0e4	slot 6 ph2 off
+	; c0e5	slot 6 ph2 on
+	; c0e6	slot 6 ph3 off
+	; c0e7	slot 6 ph3 on
+	; c0e8	slot 6 motor off
+	; c0e9	slot 6 motor on
+	; c0ea	slot 6 drive 1
+	; c0eb	slot 6 drive 2
+	; c0ec	slot 6 q6 off \                   Q6  Q7
+	; c0ed	slot 6 q6 on  |-- state machine    0  0   READ
+	; c0ee	slot 6 q7 off |                    0  1   WRITE
+	; c0ef	slot 6 q7 on  /                    1  0   SENSE WRITE PROTECT
+	;                                          1  1   WRITE LOAD
+
+        ; write sector data
+
+slotpatchw1:
+        ldx	#$d1		; cycle num smc        Q6  Q7
+        lda	$c08d, x	; prime drive		1   X
+        lda	$c08e, x	; required by Unidisk	1   0   ; senese wp?
+        tya
+        sta	$c08f, x	;                       1   1   ; write load
+        ora	$c08c, x	;                       0   1   ; write
+
+        ; 40 cycles
+
+        ldy	#4						; 2 cycles
+        cmp	$ea		; nop				; 3 cycles
+        cmp	($ea,x)		; nop				; 6 cycles
+b5:
+	jsr	writenib1					; (29 cycles)
+
+								; +6 cycles
+        dey							; 2 cycles
+        bne	b5						; 3/2nt
+
+        ; 36 cycles
+                                				; +10 cycles
+	ldy	#(prolog_e-prolog)
+								; 2 cycles
+	cmp	$ea		; nop				; 3 cycles
+b6:
+	lda	prolog-1, y					; 4 cycles
+	jsr	writenib3					; (17 cycles)
+
+	; 32 cycles if branch taken
+								; +6 cycles
+	dey							; 2 cycles
+	bne	b6						; 3/2nt
+
+        ; 36 cycles on first pass
+								; +10 cycles
+	tya							; 2 cycles
+	ldy	#$56						; 2 cycles
+b7:
+	eor	bit2tbl-1, y					; 5 cycles
+	tax							; 2 cycles
+	lda	xlattbl, x      				; 4 cycles
+slotpatchw2:
+        ldx	#$d1		; slot number smc		; 2 cycles
+        sta	$c08d, x	; wp sense			; 5 cycles
+        lda	$c08c, x	; read				; 4 cycles
+
+	; 32 cycles if branch taken
+
+        lda	bit2tbl-1, y					; 5 cycles
+        dey							; 2 cycles
+        bne     b7						; 3/2nt
+
+        ; 32 cycles
+								; +9 cycles
+        clc							; 2 cycles
+b88:
+	eor	encbuf, y					; 4 cycles
+b8:
+	tax							; 2 cycles
+        lda	xlattbl, x					; 4 cycles
+slotpatchw3:
+	ldx	#$d1		; slot number smc		; 2 cycles
+	sta	$c08d, x	; wp sense			; 5 cycles
+	lda	$c08c, x	; read				; 4 cycles
+	bcs	f1						; 3/2nt
+
+	; 32 cycles if branch taken
+
+	lda	encbuf, y					; 4 cycles
+	iny							; 2 cycles
+	bne	b88						; 3/2nt
+
+	; 32 cycles
+								; +10 cycles
+	sec							; 2 cycles
+	bcs	b8						; 3 cycles
+
+	; 32 cycles
+								; +3 cycles
+f1:
+	ldy	#(epilog_e-epilog)
+								; 2 cycles
+        cmp	($ea,x)		; nop				; 6 cycles
+b9:
+	lda	epilog-1, y					; 4 cycles
+	jsr	writenib3					; (17 cycles)
+
+	; 32 cycles if branch taken
+								; +6 cycles
+        dey							; 2 cycles
+        bne     b9						;3/2nt
+
+        lda     $c08e, x	; read/wp
+        lda     $c08c, x	; read
+        lda     $c088, x	; motor off
+	rts							; 6 cycles
+
+writenib1:
+	cmp     ($ea,x)		; nop				; 6 cycles
+	cmp     ($ea,x)		; nop				; 6 cycles
+writenib3:
+slotpatchw4:
+	ldx     #$d1		; slot number			; 2 cycles
+writenib4:
+	sta     $c08d, x	; wp sense?			; 5 cycles
+	ora     $c08c, x	; read				; 4 cycles
+	rts							; 6 cycles
+
+prolog:	.byte $ad, $aa, $d5
+prolog_e:
+epilog:	.byte $ff, $eb, $aa, $de
+epilog_e:
+
+xlattbl:
+.byte $96,$97,$9A,$9B,$9D,$9E,$9F,$A6
+.byte $A7,$AB,$AC,$AD,$AE,$AF,$B2,$B3
+.byte $B4,$B5,$B6,$B7,$B9,$BA,$BB,$BC
+.byte $BD,$BE,$BF,$CB,$CD,$CE,$CF,$D3
+.byte $D6,$D7,$D9,$DA,$DB,$DC,$DD,$DE
+.byte $DF,$E5,$E6,$E7,$E9,$EA,$EB,$EC
+.byte $ED,$EE,$EF,$F2,$F3,$F4,$F5,$F6
+.byte $F7,$F9,$FA,$FB,$FC,$FD,$FE,$FF
diff --git a/disk/save/test_write.s b/disk/save/test_write.s
new file mode 100644
index 00000000..e3b966eb
--- /dev/null
+++ b/disk/save/test_write.s
@@ -0,0 +1,157 @@
+; write track0 sector 10
+
+WAIT    = $FCA8                 ;; delay 1/2(26+27A+5A^2) us
+
+test_write:
+
+	lda	#$ec
+	sta	slotpatch1+1
+
+	jsr	popwr_init
+
+	
+
+; fill in $d00 with pattern
+
+	ldx	#0
+loop:
+	txa
+	sta	$d00,X
+	inx
+	bne	loop
+
+	; turn on motor
+	jsr	turn_on_motor
+
+	; seek to track 0
+
+	lda	#0
+	asl
+	sta	phase+1
+
+	jsr	seek
+
+	; write to sector 0
+
+	lda	#10
+	sta	requested_sector+1
+
+	jsr	sector_write
+
+
+
+
+forever:
+	jmp	forever
+
+
+seekret:
+	rts
+
+seek:
+.if 0
+        ldx     #0
+        stx     step+1
+copy_cur:
+curtrk:
+        lda     #0
+        sta     tmpval+1
+        sec
+.endif
+phase:
+        sbc     #$d1
+        beq     seekret
+.if 0
+        ; if seek backwards
+        bcs     sback
+
+        eor     #$ff
+        inc     curtrk+1
+
+        bcc     ssback
+sback:
+        adc     #$fe
+        dec     curtrk+1
+ssback:
+        cmp     step+1
+        bcc     loop10
+step:
+        lda     #$d1
+loop10:
+        cmp     #8
+        bcs     loop11
+        tay
+        sec
+loop11:
+        lda     curtrk+1
+        ldx     step1, Y
+        bne     loop12
+loopmmm:
+        clc
+        lda     tmpval+1
+        ldx     step2, Y
+loop12:
+        stx     sector+1
+        and     #3
+        rol
+        tax
+slotpatch8:
+        sta     $c0d1, X
+loopmm:
+        ldx     #$13
+loopm:
+        dex
+        bne     loopm
+        dec     sector+1
+        bne     loopmm
+        lsr
+        bcs     loopmmm
+        inc     step+1
+        bne     copy_cur
+
+step1:          .byte 1, $30, $28, $24, $20, $1e, $1d, $1c
+step2:          .byte $70, $2c, $26, $22, $1f, $1e, $1d, $1c
+.endif
+	rts
+
+
+
+
+
+
+readd5aa:
+L16:
+        jsr     readnib
+L17:
+        cmp     #$d5
+        bne     L16
+        jsr     readnib
+        cmp     #$aa
+        bne     L17
+        tay             ; we need Y=#$AA later
+readnib:
+slotpatch1:                     ; smc
+	lda	$c0d1           ; gets set to C08C (Q6L) read
+	bpl	readnib
+	rts
+
+
+;====================
+; enable drive motor
+;====================
+turn_on_motor:
+slotpatch9:
+        lda     $c0e9           ; fixme, patch
+
+        ; wait 1s
+
+        ldx     #6
+wait_1s:
+        lda     #255
+        jsr     WAIT
+        dex
+        bne     wait_1s
+
+	rts
+
+.include "qkumba_popwr.s"