diff --git a/idasm/lc16sd_blockloader.asm b/idasm/lc16sd_blockloader.asm
new file mode 100644
index 0000000..2f34660
--- /dev/null
+++ b/idasm/lc16sd_blockloader.asm
@@ -0,0 +1,82 @@
+;-----------------------
+; 'lc16sd' blockloader code
+; disassembled from munch.ptp
+;-----------------------
+	ORG	03700	; addr  code
+
+ldaddr	RCF		; 03700 0001032
+numwrd	JMS	.	; 03701 0037701 get address of 'chksum' into 'numwrd'
+
+chksum	LAC	numwrd	; 03702 0063701 are we are running in high memory (017700+)
+	SAM	himem	; 03703 0077775
+	JMP	rdblk	; 03704 0013710 if not, just load tape
+
+	LWC	012     ; 03705 0104012 else turn on the display
+	DLA		; 03706 0001003
+	DON		; 03707 0003100
+
+rdblk	CAL		; 03710 0100011 initialize block checksum
+	DAC	chksum	; 03711 0023702
+	JMS	rdword	; 03712 0037746 get load address
+	DAC	ldaddr	; 03713 0023700
+	ASP		; 03714 0002002 if high bit set
+	JMP	ldend	; 03715 0013740 then end of tape load
+	JMS	rdword	; 03716 0037746 else get number of words in block
+	DAC	numwrd	; 03717 0023701
+	JMS	rdword	; 03720 0037746 read checksum word, add to checksum
+blklp	JMS	rdword	; 03721 0037746 get data word
+	DAC	*ldaddr	; 03722 0123700 store into memory
+	LAC	ldaddr	; 03723 0063700 get load address
+	SAR	3	; 03724 0003063 echo load address in display (if running)
+	AND	low10	; 03725 0047765
+	IOR	dlya0	; 03726 0053764
+	DAC	disp	; 03727 0023766
+	LAC	*ldaddr	; 03730 0163700 get last data word
+	ISZ	ldaddr	; 03731 0033700 move 'load address' pointer
+	ISZ	numwrd	; 03732 0033701 check end of block
+	JMP	blklp	; 03733 0013721 jump if not ended
+	ADD	chksum	; 03734 0067702 block end, check checksum
+	ASZ		; 03735 0002001 if checksum invalid,
+	JMP	.	; 03736 0013736     busy wait here
+	JMP	rdblk	; 03737 0013710 else go get next block
+; end of load, AC is load address, high bit set
+ldend	DOF		; 03740 0001012 turn off the display
+	IAC		; 03741 0100004
+	ASN		; 03742 0102001 if address is 0177777
+	HLT		; 03743 0000000     then just halt
+	JMS	rdword	; 03744 0037746 else get AC contents
+	JMP	*ldaddr	; 03745 0113700 and jump to start address
+; read a word from tape, leave in AC
+rdword	DATA	0	; 03746 0000000
+	ADD	chksum	; 03747 0067702
+	DAC	chksum	; 03750 0023702
+	CAL		; 03751 0100011
+	RSF		; 03752 0002040
+	JMP	.-1	; 03753 0013752
+	RRC		; 03754 0001033
+	RAL	3	; 03755 0003003
+	RAL	3	; 03756 0003003
+	RAL	2	; 03757 0003002
+	RSF		; 03760 0002040
+	JMP	.-1	; 03761 0013760
+	RRC		; 03762 0001033
+	JMP	*rdword	; 03763 0113746
+
+dlya0	DLYA	0	; 03764 0020000
+low10	DATA	001777	; 03765 0001777
+
+; display routine, used if running in extended memory
+disp	DLYA	00000	; 03766 0020000
+	DLXA	00000	; 03767 0010000
+	DSTS	1	; 03770 0004005
+	data	0046000	;DLVH	02000	; 03771 0046000
+	DLYA	01777	; 03772 0021777
+	DHLT		; 03773 0000000
+
+	DATA	0067766	; 03774 0067766
+himem	DATA	0017702	; 03775 0017702
+	DATA	0010000	; 03776 0010000
+	DATA	0177777	; 03777 0177777
+	DATA	0000000	; 04000 0000000
+
+	END		;
diff --git a/pymlac/boot_rom.asm b/pymlac/boot_rom.asm
new file mode 100644
index 0000000..4808921
--- /dev/null
+++ b/pymlac/boot_rom.asm
@@ -0,0 +1,37 @@
+;-----------------------
+; PTR ROM code
+;-----------------------
+        org     040
+start   lac     base    ;40 get load address
+        dac     010     ;41 put into auto-inc reg
+        lwc     076     ;42 -0100+1 into AC
+        dac     020     ;43 put into memory
+        hon             ;44 start PTR
+wait    cal             ;45 clear AC+LINK
+        hsf             ;46 skip if PTR has data
+        jmp     .-1     ;47 wait until is data
+        hrb             ;50 read PTR -> AC
+        sam     what    ;51 skip if AC == 2
+        jmp     wait    ;52 wait until PTR return 0
+loop    hsf             ;53 skip if PTR has data
+        jmp     .-1     ;54 wait until is data
+        hrb             ;55 read PTR -> AC
+        ral     3       ;56 move byte into high AC
+        ral     3       ;57
+        ral     2       ;60
+        hsn             ;61 wait until PTR moves
+        jmp     .-1     ;62
+        hsf             ;63 skip if PTR has data
+        jmp     .-1     ;64 wait until is data
+        hrb             ;65 read PTR -> AC
+        dac     *010    ;66 store word, inc pointer
+        hsn             ;67 wait until PTR moves
+        jmp     .-1     ;70
+        cal             ;71 clear AC & LINK
+        isz     020     ;72 inc mem and skip zero
+        jmp     loop    ;73 if not finished, jump
+        jmp     *go     ;74 execute the blockloader
+what    data    2       ;75
+go      data    03700   ;76
+base    data    03677   ;77
+