diff --git a/blk/001 b/blk/001
index 7ae197a..495f2a9 100644
--- a/blk/001
+++ b/blk/001
@@ -1,6 +1,7 @@
 MASTER INDEX
 
-005 Z80 assembler             30-99 unused
+005 Z80 assembler             030 8086 assembler
+50-99 unused
 100 Block editor              120 Visual Editor
 160-259 unused                260 Cross compilation
 280 Z80 boot code             350 Core words
@@ -8,5 +9,5 @@ MASTER INDEX
 440-519 unused                520 Fonts
 550-649 unused
 650 AVR assembler             690 AVR SPI programmer
-700-729 unused                730 8086 assembler
+700-799 unused
 800 8086 boot code
diff --git a/blk/030 b/blk/030
new file mode 100644
index 0000000..56ea9c5
--- /dev/null
+++ b/blk/030
@@ -0,0 +1,2 @@
+( 8086 assembler. See doc/asm.txt )
+1 13 LOADR+
diff --git a/blk/751 b/blk/031
similarity index 100%
rename from blk/751
rename to blk/031
diff --git a/blk/752 b/blk/032
similarity index 100%
rename from blk/752
rename to blk/032
diff --git a/blk/753 b/blk/033
similarity index 100%
rename from blk/753
rename to blk/033
diff --git a/blk/754 b/blk/034
similarity index 100%
rename from blk/754
rename to blk/034
diff --git a/blk/755 b/blk/035
similarity index 100%
rename from blk/755
rename to blk/035
diff --git a/blk/756 b/blk/036
similarity index 100%
rename from blk/756
rename to blk/036
diff --git a/blk/757 b/blk/037
similarity index 100%
rename from blk/757
rename to blk/037
diff --git a/blk/758 b/blk/038
similarity index 100%
rename from blk/758
rename to blk/038
diff --git a/blk/760 b/blk/040
similarity index 100%
rename from blk/760
rename to blk/040
diff --git a/blk/761 b/blk/041
similarity index 100%
rename from blk/761
rename to blk/041
diff --git a/blk/762 b/blk/042
similarity index 100%
rename from blk/762
rename to blk/042
diff --git a/blk/763 b/blk/043
similarity index 100%
rename from blk/763
rename to blk/043
diff --git a/blk/280 b/blk/280
index 9892f73..1bc50e8 100644
--- a/blk/280
+++ b/blk/280
@@ -1,8 +1,8 @@
 Z80 boot code
 
 This assembles the boot binary. It requires the Z80 assembler
-(B200) and cross compilation setup (B260). It requires some
-constants to be set. See B420 for details.
+(B5) and cross compilation setup (B260). It requires some
+constants to be set. See doc/bootstrap.txt for details.
 
 RESERVED REGISTERS: At all times, IX points to RSP TOS and BC
 is IP. SP points to PSP TOS, but you can still use the stack
diff --git a/blk/730 b/blk/730
deleted file mode 100644
index 0d11a61..0000000
--- a/blk/730
+++ /dev/null
@@ -1,15 +0,0 @@
-8086 assembler
-
-Work in progress. Load with "750 LOAD".
-
-Mnemonics are followed by argument types. For example, MOVri,
-moves 8-bit immediate to 8-bit register.
-
-'r' = 8-bit register           'x' = 16-bit register
-'i' = 8-bit immediate          'I' = 16-bit immediate
-'s' = SREG register
-
-Mnemonics that only have one signature (for example INT,) don't
-have operands letters.
-
-For jumps, it's special. 's' is SHORT, 'n' is NEAR, 'f' is FAR.
diff --git a/blk/750 b/blk/750
deleted file mode 100644
index 69e4b00..0000000
--- a/blk/750
+++ /dev/null
@@ -1 +0,0 @@
-1 13 LOADR+
diff --git a/doc/asm.txt b/doc/asm.txt
index d32ce8c..4e089b3 100644
--- a/doc/asm.txt
+++ b/doc/asm.txt
@@ -5,10 +5,10 @@ There are sections, below, for each supported architectures, but
 you should read this first section first to be familiar with
 those common, basic principles)
 
-Words in the Z80 assembler (B5) allow you to assemble z80 bin-
-aries. Being Forth words, opcode assembly is a bit different
-than with a typical assembler. For example, what would tradi-
-tionally be "ld a, b" would become "A B LDrr,".
+Words in the Z80 assembler, loaded with "5 LOAD" allow you to
+assemble z80 binaries. Being Forth words, opcode assembly is a
+bit different than with a typical assembler. For example, what
+would traditionally be "ld a, b" would become "A B LDrr,".
 
 Those opcode words, of which there is a complete list below, end
 with "," to indicate that their effect is to write (,) the cor-
@@ -138,3 +138,24 @@ RR         RRC         SRL         RRA         RRCA
 CALL       RST         DJNZ
 DI         EI          EXDEHL      EXX         HALT
 NOP        RET [,c]    RETI        RETN        SCF
+
+# 8086 assembler
+
+Load with "30 LOAD". As with the Z80 assembler, it is incom-
+plete.
+
+Mnemonics are followed by argument types. For example, MOVri,
+moves 8-bit immediate to 8-bit register.
+
+'r' = 8-bit register           'x' = 16-bit register
+'i' = 8-bit immediate          'I' = 16-bit immediate
+'s' = SREG register
+
+Mnemonics that only have one signature (for example INT,) don't
+have operands letters.
+
+For jumps, it's special. 's' is SHORT, 'n' is NEAR, 'f' is FAR.
+
+# 8086 Instructions list
+
+TODO
diff --git a/recipes/pcat/Makefile b/recipes/pcat/Makefile
index 66f1509..1740ef9 100644
--- a/recipes/pcat/Makefile
+++ b/recipes/pcat/Makefile
@@ -18,8 +18,8 @@ blkfs: $(BLKPACK)
 $(STAGE):
 	$(MAKE) -C $(CDIR) stage
 
-mbr.bin: mbr.fs $(STAGE)
-	cat mbr.fs | $(STAGE) > $@
+mbr.bin: mbr.fs $(STAGE) blkfs
+	cat mbr.fs | $(STAGE) blkfs > $@
 
 $(TARGET): mbr.bin os.bin
 	cat mbr.bin os.bin > $@
diff --git a/recipes/pcat/blk/612 b/recipes/pcat/blk/612
index bf847f9..83c2a44 100644
--- a/recipes/pcat/blk/612
+++ b/recipes/pcat/blk/612
@@ -1,7 +1,7 @@
 0xff00 CONSTANT RS_ADDR
 0xfffa CONSTANT PS_ADDR
 RS_ADDR 0x80 - CONSTANT SYSVARS
-750 LOAD  ( 8086 asm )
+30 LOAD   ( 8086 asm )
 262 LOAD  ( xcomp ) 270 LOAD  ( xcomp overrides )
 805 820 LOADR ( 8086 boot code )
 353 LOAD  ( xcomp core low )
diff --git a/recipes/pcat/mbr.fs b/recipes/pcat/mbr.fs
index a1c67c7..6feec20 100644
--- a/recipes/pcat/mbr.fs
+++ b/recipes/pcat/mbr.fs
@@ -1,4 +1,4 @@
-750 LOAD
-832 LOAD
+30 LOAD
+602 LOAD
 ORG @ 256 /MOD 2 PC! 2 PC!
 H@ 256 /MOD 2 PC! 2 PC!