diff --git a/mps/code/chain.h b/mps/code/chain.h
index e47f8000c0b..d3df265a0f2 100644
--- a/mps/code/chain.h
+++ b/mps/code/chain.h
@@ -74,6 +74,8 @@ typedef struct mps_chain_s {
 } ChainStruct;
 
 
+extern Res GenDescDescribe(GenDesc gen, mps_lib_FILE *stream);
+
 extern Res ChainCreate(Chain *chainReturn, Arena arena, size_t genCount,
                        GenParamStruct *params);
 extern void ChainDestroy(Chain chain);
@@ -88,12 +90,14 @@ extern size_t ChainGens(Chain chain);
 extern Res ChainAlloc(Seg *segReturn, Chain chain, Serial genNr,
                       SegClass class, Size size, Pool pool,
                       Bool withReservoirPermit, ArgList args);
+extern Res ChainDescribe(Chain chain, mps_lib_FILE *stream);
 
 extern Bool PoolGenCheck(PoolGen gen);
 extern Res PoolGenInit(PoolGen gen, Chain chain, Serial nr, Pool pool);
 extern void PoolGenFinish(PoolGen gen);
 extern void PoolGenFlip(PoolGen gen);
 #define PoolGenNr(gen) ((gen)->nr)
+extern Res PoolGenDescribe(PoolGen gen, mps_lib_FILE *stream);
 
 
 #endif /* chain_h */
diff --git a/mps/code/global.c b/mps/code/global.c
index d9820e19981..3cb232124fd 100644
--- a/mps/code/global.c
+++ b/mps/code/global.c
@@ -1120,6 +1120,12 @@ Res GlobalsDescribe(Globals arenaGlobals, mps_lib_FILE *stream)
     if (res != ResOK) return res;
   }
 
+  RING_FOR(node, &arena->chainRing, nextNode) {
+    Chain chain = RING_ELT(Chain, chainRing, node);
+    res = ChainDescribe(chain, stream);
+    if (res != ResOK) return res;
+  }
+
   TRACE_SET_ITER(ti, trace, TraceSetUNIV, arena)
     if (TraceSetIsMember(arena->busyTraces, trace)) {
       res = TraceDescribe(trace, stream);
diff --git a/mps/code/locus.c b/mps/code/locus.c
index a704c8b820b..f90e146f675 100644
--- a/mps/code/locus.c
+++ b/mps/code/locus.c
@@ -126,6 +126,36 @@ static Size GenDescTotalSize(GenDesc gen)
 }
 
 
+/* GenDescDescribe -- describe a generation in a chain */
+
+Res GenDescDescribe(GenDesc gen, mps_lib_FILE *stream)
+{
+  Res res;
+  Ring node, nextNode;
+
+  if (!TESTT(GenDesc, gen)) return ResFAIL;
+  if (stream == NULL) return ResFAIL;
+
+  res = WriteF(stream,
+               "GenDesc $P {\n", (WriteFP)gen,
+               "zones $B\n", (WriteFB)gen->zones,
+               "capacity $U\n", (WriteFU)gen->capacity,
+               "mortality $D\n", (WriteFD)gen->mortality,
+               "proflow $D\n", (WriteFD)gen->proflow,
+               NULL);
+  if (res != ResOK) return res;
+
+  RING_FOR(node, &gen->locusRing, nextNode) {
+    PoolGen pgen = RING_ELT(PoolGen, genRing, node);
+    res = PoolGenDescribe(pgen, stream);
+    if (res != ResOK) return res;
+  }
+
+  res = WriteF(stream, "} GenDesc $P\n", (WriteFP)gen, NULL);
+  return res;
+}
+
+
 /* ChainCreate -- create a generation chain */
 
 Res ChainCreate(Chain *chainReturn, Arena arena, size_t genCount,
@@ -411,6 +441,35 @@ void ChainEndGC(Chain chain, Trace trace)
 }
 
 
+/* ChainDescribe -- describe a chain */
+
+Res ChainDescribe(Chain chain, mps_lib_FILE *stream)
+{
+  Res res;
+  size_t i;
+
+  if (!TESTT(Chain, chain)) return ResFAIL;
+  if (stream == NULL) return ResFAIL;
+
+  res = WriteF(stream,
+               "Chain $P {\n", (WriteFP)chain,
+               "arena $P\n", (WriteFP)chain->arena,
+               "activeTraces $B\n", (WriteFB)chain->activeTraces,
+               NULL);
+  if (res != ResOK) return res;
+
+  for (i = 0; i < chain->genCount; ++i) {
+    res = GenDescDescribe(&chain->gens[i], stream);
+    if (res != ResOK) return res;
+  }
+
+  res = WriteF(stream,
+               "} Chain $P\n", (WriteFP)chain,
+               NULL);
+  return res;
+}
+
+
 /* PoolGenInit -- initialize a PoolGen */
 
 Res PoolGenInit(PoolGen gen, Chain chain, Serial nr, Pool pool)
@@ -464,6 +523,30 @@ Bool PoolGenCheck(PoolGen gen)
 }
 
 
+/* PoolGenDescribe -- describe a PoolGen */
+
+Res PoolGenDescribe(PoolGen pgen, mps_lib_FILE *stream)
+{
+  Res res;
+
+  if (!TESTT(PoolGen, pgen)) return ResFAIL;
+  if (stream == NULL) return ResFAIL;
+  
+  res = WriteF(stream,
+               "PoolGen $P ($U) {\n", (WriteFP)pgen, (WriteFU)pgen->nr,
+               "pool $P ($U) \"$S\"\n",
+               (WriteFP)pgen->pool, (WriteFU)pgen->pool->serial,
+               (WriteFS)pgen->pool->class->name,
+               "chain $P\n", (WriteFP)pgen->chain,
+               "totalSize $U\n", (WriteFU)pgen->totalSize,
+               "newSize $U\n", (WriteFU)pgen->newSize,
+               "newSizeAtCreate $U\n", (WriteFU)pgen->newSizeAtCreate,
+               "} PoolGen $P\n", (WriteFP)pgen,
+               NULL);
+  return res;
+}
+
+
 /* LocusInit -- initialize the locus module */
 
 void LocusInit(Arena arena)