diff --git a/Programs/CosmOS/Apps/Edit.asm b/Programs/CosmOS/Apps/Edit.asm
index be4b28f..ddc3cde 100644
--- a/Programs/CosmOS/Apps/Edit.asm
+++ b/Programs/CosmOS/Apps/Edit.asm
@@ -529,7 +529,6 @@ listStep:
   PSHD.3
   POPD.0
   DPUP.0 0d03
-  SETD.1 Leftover
   LDA.1
   BRA listEmpty
 listChars:
@@ -723,7 +722,6 @@ writeOut:
   CCF
   SUB
   MVQA
-  SETD.0 WroteSize
   STA.0                     ; WroteSize is now a count of bytes, which is what gets printed.
 
   ; And into the two registers the service takes a size in.
diff --git a/Programs/CosmOS/Apps/Pour.asm b/Programs/CosmOS/Apps/Pour.asm
index 197a0d2..5ec5afb 100644
--- a/Programs/CosmOS/Apps/Pour.asm
+++ b/Programs/CosmOS/Apps/Pour.asm
@@ -34,7 +34,6 @@ counted:
   LDA.0
   BNA haveCount
   INIA 0d1
-  SETD.0 Blocks
   STA.0
 haveCount:
 
@@ -159,7 +158,6 @@ countLoop:
   SETD.1 Blocks
   LDB.1
   PSHA
-  RSTA
   INIA 0d10
   CALL timesTen
   POPA
@@ -191,7 +189,6 @@ tenLoop:
   CCF
   ADD
   MVQA
-  SETD.0 Scratch
   STA.0
   POPA
   DECA
diff --git a/Programs/CosmOS/Apps/Snake.asm b/Programs/CosmOS/Apps/Snake.asm
index 12f444c..4f5621b 100644
--- a/Programs/CosmOS/Apps/Snake.asm
+++ b/Programs/CosmOS/Apps/Snake.asm
@@ -334,7 +334,6 @@ takeKeyTurn:
   XOR
   POPA
   BRQ takeKeyDone           ; Opposite, so it is not a turn anybody can make.
-  SETD.0 Direction
   STA.0
   RET
 
@@ -430,7 +429,6 @@ stepDown:
   INIB 0xF0
   AND
   MVQA
-  INIB 0xF0
   XOR
   POPA
   BRQ stepWall              ; The bottom row is where the high nibble is fifteen.
@@ -453,7 +451,6 @@ stepRight:
   INIB 0x0F
   AND
   MVQA
-  INIB 0x0F
   XOR
   POPA
   BRQ stepWall
diff --git a/Programs/CosmOS/Assembler/Asm.asm b/Programs/CosmOS/Assembler/Asm.asm
index 0d03936..4c63542 100644
--- a/Programs/CosmOS/Assembler/Asm.asm
+++ b/Programs/CosmOS/Assembler/Asm.asm
@@ -1277,7 +1277,6 @@ dropColon:
   LDA.0
   BRA dropColonDone
   DECA
-  SETD.0 TokLength
   STA.0
   SETD.0 TokText
   SETD.1 DropWalk
@@ -1525,7 +1524,6 @@ checkImageRoom:
   LDA.1
   SETD.0 ImgOutBlocks
   STA.0                     ; The high half is whole blocks.
-  SETD.1 ImgAsk
   INCD.1
   LDA.1
   SETD.0 ImgOutTail
@@ -2034,7 +2032,6 @@ writeImage:
   LDA.1
   SETD.0 ImgOutBlocks
   STA.0
-  SETD.1 ImgTotal
   INCD.1
   LDA.1
   SETD.0 ImgOutTail
diff --git a/Programs/CosmOS/Assembler/vectors.asm b/Programs/CosmOS/Assembler/vectors.asm
index 2f6ee73..1e39956 100644
--- a/Programs/CosmOS/Assembler/vectors.asm
+++ b/Programs/CosmOS/Assembler/vectors.asm
@@ -189,7 +189,6 @@ vecReadFields:
   STA.1
   INCD.0
   LDA.0
-  SETD.1 VecHandler
   INCD.1
   STA.1
   INCD.0
diff --git a/Programs/CosmOS/README.md b/Programs/CosmOS/README.md
index a942d5f..16bb204 100644
--- a/Programs/CosmOS/README.md
+++ b/Programs/CosmOS/README.md
@@ -462,7 +462,7 @@ Typed in as bytes, checked by disassembling it back, and run. It ends with `SWI
 
 `Edit` is the first program on this machine that makes a file a person typed - every byte on every disk before it was put there by the host tool. It is line oriented in the manner of `ed`: `l` lists, `a` adds at the end, `i` and `c` and `d` take a line number, `w` writes and `q` stops.
 
-It includes nothing but `services.asm` and `text.asm`: the filesystem and the console are the system's, asked for rather than carried. That is what brought `Edit` down from 4,941 bytes to 1,995 bytes without a line of its own logic changing - and the way that was checked is worth knowing, because the recorded output of the `cosmosEdit` test did not move by a single byte across the rewrite.
+It includes nothing but `services.asm` and `text.asm`: the filesystem and the console are the system's, asked for rather than carried. That is what brought `Edit` down from 4,941 bytes to 1,983 bytes without a line of its own logic changing - and the way that was checked is worth knowing, because the recorded output of the `cosmosEdit` test did not move by a single byte across the rewrite.
 
 It keeps the document as a **linked list of lines** rather than one buffer with newlines in it. Each line says where the next one is, how long it is, and then its bytes. Inserting is two pointers changed and nothing moved; with a flat buffer it would mean shifting every byte after the edit, on a machine whose only block move is a device asked politely. The price is that deleted lines are not reused, so a heavy session uses more room than the document needs and writing it out is what tidies up.
 
diff --git a/Programs/CosmOS/Source/cosmos.asm b/Programs/CosmOS/Source/cosmos.asm
index c9dc41a..571f2e9 100644
--- a/Programs/CosmOS/Source/cosmos.asm
+++ b/Programs/CosmOS/Source/cosmos.asm
@@ -402,7 +402,6 @@ dirCheck:
   STA.1
   SETD.0 SbfsFileTail
   LDA.0
-  SETD.1 DirSize
   INCD.1
   STA.1
 
@@ -446,12 +445,10 @@ dirDone:
   STA.1
   SETD.0 DirSeen
   LDA.0
-  SETD.1 DirTaken
   LDB.1
   CCF
   SUB
   MVQA
-  SETD.0 DirSeen
   STA.0
 
   SETD.0 DirSeen
@@ -2327,7 +2324,6 @@ bankSet:
   LDB.0
   SETD.1 BankWas
   STB.1
-  SETD.0 DumpBank
   STA.0
 
   ; Naming a bank puts the cursor at the start of it, which is the only answer that does
@@ -2390,10 +2386,8 @@ showAt:
   LDA.0
   SETD.1 DumpAt
   STA.1
-  SETD.0 TextValue
   INCD.0
   LDA.0
-  SETD.1 DumpAt
   INCD.1
   STA.1
 
@@ -2694,7 +2688,6 @@ showInstruction:
   CALL printByteHex
   INIA 0x20
   OUTA 0x00
-  INIA 0x20
   OUTA 0x00
 
   CALL aimAtDumpAt
@@ -3210,7 +3203,6 @@ takeMnemonicPad:
   INIA 0x20
   STA.1
   INCD.1
-  SETD.2 AsmLeft
   LDA.2
   DECA
   STA.2
diff --git a/Programs/CosmOS/Source/sbfs.asm b/Programs/CosmOS/Source/sbfs.asm
index 0044e5d..e7ae6d2 100644
--- a/Programs/CosmOS/Source/sbfs.asm
+++ b/Programs/CosmOS/Source/sbfs.asm
@@ -943,10 +943,10 @@ sbfsFirst:
   STA.0
   BRI sbfsWalkScan
 
+; The pointer and the count were stepped when the last entry was handed out, so there is
+; nothing to do here but carry on looking - which is what the next label does, so this one
+; falls into it rather than branching to the line below itself.
 sbfsNext:
-  ; The pointer and the count were stepped when the last entry was handed out, so there
-  ; is nothing to do here but carry on looking.
-  BRI sbfsWalkScan
 
 sbfsWalkScan:
   ; Anything left in the block in hand?
diff --git a/Programs/CosmOS/Source/text.asm b/Programs/CosmOS/Source/text.asm
index 7fdda6f..b9033bf 100644
--- a/Programs/CosmOS/Source/text.asm
+++ b/Programs/CosmOS/Source/text.asm
@@ -272,7 +272,6 @@ textNumberLoop:
   POPB
   CCF
   ADD                           ; And the digit.
-  SETD.1 TextValue
   STQ.1
 
   SETD.1 TextDigits
diff --git a/Programs/testPrograms/sbfsWalkTest.asm b/Programs/testPrograms/sbfsWalkTest.asm
index c8c24e1..2844f1d 100644
--- a/Programs/testPrograms/sbfsWalkTest.asm
+++ b/Programs/testPrograms/sbfsWalkTest.asm
@@ -66,7 +66,6 @@ walkCheck:
   STA.1
   SETD.0 SbfsFileTail
   LDA.0
-  SETD.1 Size
   INCD.1
   STA.1
 
diff --git a/Programs/testPrograms/waitTest.asm b/Programs/testPrograms/waitTest.asm
index 619d527..7c927bd 100644
--- a/Programs/testPrograms/waitTest.asm
+++ b/Programs/testPrograms/waitTest.asm
@@ -26,7 +26,6 @@ start:
   OUTA 0xE8
   RSTA
   OUTA 0x20
-  RSTA
   OUTA 0x21
   INIA 0x01
   OUTA 0x22
diff --git a/Tests/expected/cosmosMonitor.out b/Tests/expected/cosmosMonitor.out
index 83fb026..7dcf55f 100644
--- a/Tests/expected/cosmosMonitor.out
+++ b/Tests/expected/cosmosMonitor.out
@@ -63,7 +63,7 @@ finished
 * > greet.sbx               210
 hello.sbx               52
 Life.sbx                1409
-Snake.sbx               2175
+Snake.sbx               2167
 Keys.sbx                663
 Say.sbx                 155
 Break.sbx               148
diff --git a/Tests/expected/cosmosRun.out b/Tests/expected/cosmosRun.out
index c471318..d835bb6 100644
--- a/Tests/expected/cosmosRun.out
+++ b/Tests/expected/cosmosRun.out
@@ -3,7 +3,7 @@ CosmOS
 > greet.sbx               210
 hello.sbx               52
 Life.sbx                1409
-Snake.sbx               2175
+Snake.sbx               2167
 Keys.sbx                663
 Say.sbx                 155
 Break.sbx               148
diff --git a/Tests/expected/cosmosSlowDisk.out b/Tests/expected/cosmosSlowDisk.out
index 153bdcc..c998466 100644
--- a/Tests/expected/cosmosSlowDisk.out
+++ b/Tests/expected/cosmosSlowDisk.out
@@ -2,7 +2,7 @@ CosmOS
 > greet.sbx               210
 hello.sbx               52
 Life.sbx                1409
-Snake.sbx               2175
+Snake.sbx               2167
 Keys.sbx                663
 Say.sbx                 155
 Break.sbx               148
diff --git a/Tests/expected/cosmosTreeWrite.out b/Tests/expected/cosmosTreeWrite.out
index 561e2a3..6192d57 100644
--- a/Tests/expected/cosmosTreeWrite.out
+++ b/Tests/expected/cosmosTreeWrite.out
@@ -1,13 +1,13 @@
 CosmOS
 > Folder                  <dir>
-Edit.sbx                1995
+Edit.sbx                1983
 1 file, 1 directory
 > loaded, starting at 4000
 > note.txt, 0 lines
 > : : : > written, 67 bytes
 > finished
 > Folder                  <dir>
-Edit.sbx                1995
+Edit.sbx                1983
 note.txt                67
 2 files, 1 directory
 > halted