diff --git a/Programs/Boot/slotData.asm b/Programs/Boot/slotData.asm
new file mode 100644
index 0000000..dc9b73d
--- /dev/null
+++ b/Programs/Boot/slotData.asm
@@ -0,0 +1,65 @@
+; slotData.asm
+; A boot slot payload that arranges its own Data Segment.
+;
+; Stage one places Program Memory and nothing else, because knowing where a payload's data
+; ends and its code begins would mean knowing a format, and knowing formats is the thing
+; ROM must do as little of as possible. So a payload that wants initialised data arranges
+; it: a loadable image is written into the slot as code followed by data, which leaves the
+; data image sitting in Program Memory just past the code, and the first thing the payload
+; does is blit it down to where it was assembled for.
+;
+; This is how the real second stage will get the Data Segment that sbfs.asm needs.
+;
+; THE PADDING IS NOT DECORATION. The blit needs a length, the assembler will not work out
+; a difference between two labels, so the segment is padded to a round number and that
+; number is what gets copied. Reserve one byte too many and the last byte does not arrive:
+; the first draft of this padded to 257 and copied 256.
+;
+; Written by Anachronaut
+#Program
+  #Base 0xC000
+
+start:
+  RSTA
+  OUTA 0xE0             ; SourceBank: Program Memory, where stage one put everything.
+  SETD.0 codeEnd
+  PSHD.0
+  POPA
+  POPB
+  OUTB 0xE1
+  OUTA 0xE2
+  INIA 0d1
+  OUTA 0xE3             ; DestBank: Data Memory.
+  SETD.0 Greeting
+  PSHD.0
+  POPA
+  POPB
+  OUTB 0xE4
+  OUTA 0xE5
+  INIA 0x01
+  OUTA 0xE6
+  RSTA
+  OUTA 0xE7             ; A round 256 bytes, which the segment is padded to.
+  INIA 0x01
+  OUTA 0xE8
+
+  SETD.0 Greeting
+sayLoop:
+  LDA.0
+  BRA sayDone
+  OUTA 0x00
+  INCD.0
+  BRI sayLoop
+sayDone:
+  HALT
+
+codeEnd:
+
+#Data
+  #Base 0x3000
+
+Greeting:
+"a payload with data of its own
+"
+Padding:
+  #Reserve 0d224
diff --git a/Tests/expected/bootDataRuns.out b/Tests/expected/bootDataRuns.out
new file mode 100644
index 0000000..53dc6fe
--- /dev/null
+++ b/Tests/expected/bootDataRuns.out
@@ -0,0 +1,3 @@
+a payload with data of its own
+Execution halted.
+[exit 0]
diff --git a/Tests/lint-baseline.txt b/Tests/lint-baseline.txt
index 3042a1b..c7d6a01 100644
--- a/Tests/lint-baseline.txt
+++ b/Tests/lint-baseline.txt
@@ -1,3 +1,4 @@
+Programs/Boot/slotData.asm	redundant-setd	1
 Programs/Boot/stage1.asm	redundant-setd	2
 Programs/CosmOS/Apps/Copy.asm	redundant-setd	2
 Programs/CosmOS/Apps/Edit.asm	redundant-setd	3
diff --git a/Tests/makedisks.sh b/Tests/makedisks.sh
index 4d5f7f2..7e5bf43 100755
--- a/Tests/makedisks.sh
+++ b/Tests/makedisks.sh
@@ -377,3 +377,12 @@ tail -c +17 "$WORK/otherSlot.sbx" > "$WORK/otherSlot.raw"
 # And the same disk with the other slot chosen, so both are exercised.
 cp "$DISKS/chain.img" "$DISKS/chainAlt.img"
 "$TOOL" bootslot "$DISKS/chainAlt.img" 1 >/dev/null
+
+# And a slot whose payload has a Data Segment of its own. Stage one places Program Memory
+# and nothing else, so the payload copies its data down from just past its own code - which
+# is the mechanism the real second stage will need, since sbfs.asm has variables and a
+# string it compares against.
+"$TOOL" format "$DISKS/chainData.img" 256 4 4 >/dev/null
+"$ROOT/Assembler" "$ROOT/Programs/Boot/slotData.asm" -o "$WORK/slotData.sbx" >/dev/null
+tail -c +17 "$WORK/slotData.sbx" > "$WORK/slotData.raw"
+"$TOOL" boot "$DISKS/chainData.img" "$WORK/slotData.raw" 0 >/dev/null
diff --git a/Tests/manifest b/Tests/manifest
index 0ae5409..64176f6 100644
--- a/Tests/manifest
+++ b/Tests/manifest
@@ -368,6 +368,12 @@ bootChainAlt         | Boot/stage1.asm                    | run      | -
 # A disk with no boot area cannot be started, and says so in the one character a ROM has
 # room to say anything in.
 bootNoArea           | Boot/stage1.asm                    | run      | -                  | -     | disks/sbfs.img
+# A payload that arranges its own Data Segment, by copying it down from just past its own
+# code. Stage one places Program Memory and nothing else - knowing where a payload's data
+# ended would mean knowing a format - so this is how the real second stage will get the
+# variables and the string that sbfs.asm needs.
+bootData             | Boot/slotData.asm                  | assemble | -                  | -
+bootDataRuns         | Boot/stage1.asm                    | run      | -                  | -     | disks/chainData.img
 # Reading a disk that has directories on it. The machine can walk a path at this point but
 # cannot make a directory, so the disk is built by the host tool and read here - which is
 # the two implementations checking each other rather than either checking itself.