diff --git a/subx/036global_variables.cc b/subx/036global_variables.cc
index 2299b3bf..78824262 100644
--- a/subx/036global_variables.cc
+++ b/subx/036global_variables.cc
@@ -104,9 +104,26 @@ void replace_global_variables_in_data_segment(segment& data, const map<string, u
     for (int j = 0;  j < SIZE(l.words);  ++j) {
       const word& curr = l.words.at(j);
       if (!contains_key(address, curr.data)) {
-        if (!looks_like_hex_int(curr.data))
+        if (looks_like_hex_int(curr.data)) {
+          if (has_operand_metadata(curr, "imm32"))
+            emit_hex_bytes(new_l, curr, 4);
+          else if (has_operand_metadata(curr, "imm16"))
+            emit_hex_bytes(new_l, curr, 2);
+          else if (has_operand_metadata(curr, "imm8"))
+            emit_hex_bytes(new_l, curr, 1);
+          else if (has_operand_metadata(curr, "disp8"))
+            raise << "can't use /disp8 in a non-code segment\n" << end();
+          else if (has_operand_metadata(curr, "disp16"))
+            raise << "can't use /disp16 in a non-code segment\n" << end();
+          else if (has_operand_metadata(curr, "disp32"))
+            raise << "can't use /disp32 in a non-code segment\n" << end();
+          else
+            new_l.words.push_back(curr);
+        }
+        else {
           raise << "missing reference to global '" << curr.data << "'\n" << end();
-        new_l.words.push_back(curr);
+          new_l.words.push_back(curr);
+        }
         continue;
       }
       trace(99, "transform") << curr.data << " maps to " << HEXWORD << get(address, curr.data) << end();
@@ -193,6 +210,19 @@ y:
 +load: 0x0a000003 -> 0a
 $error: 0
 
+:(scenario raw_number_with_imm32_in_data_segment)
+== 0x1
+b9  x/imm32
+== 0x0a000000
+x:
+  1/imm32
+# check that we loaded 'x' with the address of 1
++load: 0x0a000000 -> 01
++load: 0x0a000001 -> 00
++load: 0x0a000002 -> 00
++load: 0x0a000003 -> 00
+$error: 0
+
 :(scenario duplicate_global_variable)
 % Hide_errors = true;
 == 0x1
diff --git a/subx/051test.subx b/subx/051test.subx
index 2ae907c1..ceccc076 100644
--- a/subx/051test.subx
+++ b/subx/051test.subx
@@ -82,12 +82,12 @@ $check-ints-equal:end:
 # convenient to have when printing messages and so on
 Newline:
     # size
-    01 00 00 00
+    1/imm32
     # data
     0a/newline
 
 # every test failure increments this counter
 Num-test-failures:
-    00 00 00 00
+    0/imm32
 
 # . . vim:nowrap:textwidth=0
diff --git a/subx/053new-segment.subx b/subx/053new-segment.subx
index 0aee0539..fd7203b9 100644
--- a/subx/053new-segment.subx
+++ b/subx/053new-segment.subx
@@ -48,16 +48,16 @@ $new-segment:end:
 # various constants used here were found in the Linux sources (search for file mman-common.h)
 _mmap-new-segment:  # type mmap_arg_struct
     # addr
-    00 00 00 00  # null
+    0/imm32
     # len
-    00 00 00 00  # 0x1000
+    0/imm32
     # protection flags
-    03 00 00 00  # PROT_READ | PROT_WRITE
+    3/imm32  # PROT_READ | PROT_WRITE
     # sharing flags
-    22 00 00 00  # MAP_PRIVATE | MAP_ANONYMOUS
+    0x22/imm32  # MAP_PRIVATE | MAP_ANONYMOUS
     # fd
-    ff ff ff ff  # -1 since MAP_ANONYMOUS is specified
+    -1/imm32  # since MAP_ANONYMOUS is specified
     # offset
-    00 00 00 00  # 0 since MAP_ANONYMOUS is specified
+    0/imm32  # since MAP_ANONYMOUS is specified
 
 # . . vim:nowrap:textwidth=0
diff --git a/subx/056trace.subx b/subx/056trace.subx
index aa73bbdd..479569a7 100644
--- a/subx/056trace.subx
+++ b/subx/056trace.subx
@@ -22,17 +22,17 @@
 
 # We'll save the address of the trace segment here.
 Trace-stream:
-    00 00 00 00
+    0/imm32
 
 # Fake trace-stream for tests.
 # Also illustrates the layout of the real trace-stream (segment).
 _test-trace-stream:
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (= 8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
diff --git a/subx/057write.subx b/subx/057write.subx
index c1712996..2a111dd3 100644
--- a/subx/057write.subx
+++ b/subx/057write.subx
@@ -154,11 +154,11 @@ test-write-appends:
 
 _test-stream:
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (= 8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
diff --git a/subx/060read.subx b/subx/060read.subx
index a54b3f02..fcf38dde 100644
--- a/subx/060read.subx
+++ b/subx/060read.subx
@@ -351,11 +351,11 @@ test-read-returns-0-on-end-of-file:
 
 _test-tmp-stream:
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (= 8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
diff --git a/subx/061read-byte.subx b/subx/061read-byte.subx
index a915d436..d3192ce1 100644
--- a/subx/061read-byte.subx
+++ b/subx/061read-byte.subx
@@ -13,13 +13,13 @@
 # buffered-file.
 Stdin:
     # file descriptor or (address stream)
-    00 00 00 00  # 0 = standard input
+    0/imm32  # standard input
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
@@ -291,11 +291,11 @@ _test-buffered-file:
     # file descriptor or (address stream)
     _test-stream/imm32
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (6)
-    06 00 00 00
+    0/imm32
+    # length
+    6/imm32
     # data
     00 00 00 00 00 00  # 6 bytes
 
diff --git a/subx/062write-stream.subx b/subx/062write-stream.subx
index a4dd73b7..b273336b 100644
--- a/subx/062write-stream.subx
+++ b/subx/062write-stream.subx
@@ -228,12 +228,12 @@ test-write-stream-appends:
 
 _test-stream2:
     # current write index
-    04 00 00 00
+    4/imm32
     # current read index
-    01 00 00 00
-    # length (= 8)
-    08 00 00 00
+    1/imm32
+    # length
+    8/imm32
     # data
-    41 42 43 44 00 00 00 00  # 8 bytes
+    41/A 42/B 43/C 44/D 00 00 00 00  # 8 bytes
 
 # . . vim:nowrap:textwidth=0
diff --git a/subx/064write-byte.subx b/subx/064write-byte.subx
index 1d14b06b..61ed4197 100644
--- a/subx/064write-byte.subx
+++ b/subx/064write-byte.subx
@@ -9,13 +9,13 @@
 # The buffered file for standard output.
 Stdout:
     # file descriptor or (address stream)
-    01 00 00 00  # 1 = standard output
+    1/imm32  # standard output
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
diff --git a/subx/068error-byte.subx b/subx/068error-byte.subx
index 5f9a4ada..1bf77be5 100644
--- a/subx/068error-byte.subx
+++ b/subx/068error-byte.subx
@@ -96,13 +96,13 @@ $error-byte:dead-end:
 # The buffered file for standard error.
 Stderr:
     # file descriptor or (address stream)
-    02 00 00 00  # 1 = standard error
+    2/imm32  # standard error
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
diff --git a/subx/069allocate.subx b/subx/069allocate.subx
index 1d9e043a..7efeb678 100644
--- a/subx/069allocate.subx
+++ b/subx/069allocate.subx
@@ -22,7 +22,7 @@
 # hitherto unused bit of memory.
 Heap:
     Start-of-heap/imm32  # curr
-    00 00 00 0b  # limit = 0x0b000000; keep sync'd with DATA_SEGMENT + SEGMENT_ALIGNMENT
+    0x0b000000/imm32  # limit; keep sync'd with DATA_SEGMENT + SEGMENT_ALIGNMENT
 
 == code
 #   instruction                     effective address                                                   register    displacement    immediate
diff --git a/subx/apps/crenshaw2-1.subx b/subx/apps/crenshaw2-1.subx
index 53b59263..ad8dad46 100644
--- a/subx/apps/crenshaw2-1.subx
+++ b/subx/apps/crenshaw2-1.subx
@@ -574,26 +574,26 @@ $is-digit?:end:
 
 == data
 
-Look: # (char)
-    00 00 00 00  # = 0
+Look:  # (char with some extra padding)
+    0/imm32
 
 _test-output-stream:
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (= 8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
 _test-error-stream:
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (= 8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
diff --git a/subx/apps/crenshaw2-1b.subx b/subx/apps/crenshaw2-1b.subx
index 3b828735..044221eb 100644
--- a/subx/apps/crenshaw2-1b.subx
+++ b/subx/apps/crenshaw2-1b.subx
@@ -771,26 +771,26 @@ $is-digit?:end:
 
 == data
 
-Look: # (char)
-    00 00 00 00  # = 0
+Look:  # (char with some extra padding)
+    0/imm32
 
 _test-output-stream:
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (= 8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
 _test-error-stream:
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (= 8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
diff --git a/subx/apps/handle.subx b/subx/apps/handle.subx
index bf452cc1..3848eb76 100644
--- a/subx/apps/handle.subx
+++ b/subx/apps/handle.subx
@@ -356,6 +356,6 @@ test-lookup-failure:
 
 # Monotonically increasing counter for calls to 'new'
 Next-alloc-id:
-    01 00 00 00  # 1
+    1/imm32
 
 # . . vim:nowrap:textwidth=0
diff --git a/subx/apps/hex.subx b/subx/apps/hex.subx
index d841fd8b..49ca3bd4 100644
--- a/subx/apps/hex.subx
+++ b/subx/apps/hex.subx
@@ -1511,11 +1511,11 @@ test-skip-until-newline:
 
 _test-error-stream:
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (= 8)
-    08 00 00 00
+    0/imm32
+    # length
+    8/imm32
     # data
     00 00 00 00 00 00 00 00  # 8 bytes
 
@@ -1524,11 +1524,11 @@ _test-error-buffered-file:
     # file descriptor or (address stream)
     _test-error-stream/imm32
     # current write index
-    00 00 00 00
+    0/imm32
     # current read index
-    00 00 00 00
-    # length (6)
-    06 00 00 00
+    0/imm32
+    # length
+    6/imm32
     # data
     00 00 00 00 00 00  # 6 bytes
 
diff --git a/subx/examples/ex11.subx b/subx/examples/ex11.subx
index bb3c8e23..071a855b 100644
--- a/subx/examples/ex11.subx
+++ b/subx/examples/ex11.subx
@@ -343,7 +343,7 @@ write-stderr:  # s : (address array byte) -> <void>
 
 Newline:
     # size
-    01 00 00 00
+    1/imm32
     # data
     0a/newline
 
diff --git a/subx/examples/ex12.subx b/subx/examples/ex12.subx
index 9cf5e14a..4518aecc 100644
--- a/subx/examples/ex12.subx
+++ b/subx/examples/ex12.subx
@@ -29,16 +29,16 @@
 # various constants used here were found in the Linux sources (search for file mman-common.h)
 Mmap-new-segment:  # type mmap_arg_struct
     # addr
-    00 00 00 00  # null
+    0/imm32
     # len
-    00 01 00 00  # 0x1000
+    0x100/imm32
     # protection flags
-    03 00 00 00  # PROT_READ | PROT_WRITE
+    3/imm32  # PROT_READ | PROT_WRITE
     # sharing flags
-    22 00 00 00  # MAP_PRIVATE | MAP_ANONYMOUS
+    0x22/imm32  # MAP_PRIVATE | MAP_ANONYMOUS
     # fd
-    ff ff ff ff  # -1 since MAP_ANONYMOUS is specified
+    -1/imm32  # since MAP_ANONYMOUS is specified
     # offset
-    00 00 00 00  # 0 since MAP_ANONYMOUS is specified
+    0/imm32  # since MAP_ANONYMOUS is specified
 
 # . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex4.subx b/subx/examples/ex4.subx
index 3060ae3f..b18a5da0 100644
--- a/subx/examples/ex4.subx
+++ b/subx/examples/ex4.subx
@@ -35,6 +35,6 @@ cd/syscall  0x80/imm8
 == data
 
 X:
-    00 00 00 00  # space for read() to write to
+    0/imm32  # space for read() to write to
 
 # . . vim:nowrap:textwidth=0
diff --git a/subx/examples/ex6.subx b/subx/examples/ex6.subx
index dece5b13..3375fb43 100644
--- a/subx/examples/ex6.subx
+++ b/subx/examples/ex6.subx
@@ -28,7 +28,7 @@
 == data
 
 Size:  # size of string
-    0e 00 00 00  # 14
+    0x0e/imm32  # 14
 X:  # string to print
     48 65 6c 6c 6f 2c 20 77 6f 72 6c 64 21 0a       00
 #   H  e  l  l  o  ,  ␣  w  o  r  l  d  !  newline  null
diff --git a/subx/examples/ex7.subx b/subx/examples/ex7.subx
index 47b51734..c6dd3423 100644
--- a/subx/examples/ex7.subx
+++ b/subx/examples/ex7.subx
@@ -94,12 +94,13 @@
 == data
 
 Stream:
-    00 00 00 00
+    0/imm32
 A:
-    61 00 00 00
+    61/imm32/A
 B:
-    00 00 00 00
+    0/imm32
 Filename:
     2e 66 6f 6f 00 00 00 00
+#   .  f  o  o  null
 
 # . . vim:nowrap:textwidth=0