diff --git a/mps/src/amsss.c b/mps/src/amsss.c
index e69de29bb2d..ddbce25bec5 100644
--- a/mps/src/amsss.c
+++ b/mps/src/amsss.c
@@ -0,0 +1,136 @@
+/* impl.c.amsss: POOL CLASS AMS STRESS TEST
+ *
+ * $HopeName: MMsrc!amsss.c(MMdevel_poolams.1) $
+ * Copyright (C) 1996, 1997 Harlequin Group, all rights reserved
+ *
+ * A direct copy of amcss.c, with trivial changes.  nickb 1997-08-14
+ */
+
+#include "testlib.h"
+#include "mps.h"
+#include "mpscams.h"
+#include "fmtdy.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <math.h>
+#include <string.h>
+#include <assert.h>
+#ifdef MPS_OS_SU
+#include "ossu.h"
+#endif
+
+#define NR_EXACT_ROOTS  50
+#define NR_AMBIG_ROOTS  50
+#define FIELDS_MAX      2000
+#define COLLECTIONS	5
+#define OBJNULL         ((mps_addr_t)0xDECEA5ED)
+
+static mps_pool_t pool;
+static mps_ap_t ap;
+static mps_addr_t exact_roots[NR_EXACT_ROOTS];
+static mps_addr_t ambig_roots[NR_AMBIG_ROOTS];
+
+static mps_addr_t make(void)
+{
+  size_t length = rnd() % 20, size = (length+2)*sizeof(mps_word_t);
+  mps_addr_t p;
+  mps_res_t res;
+
+  do {
+    MPS_RESERVE_BLOCK(res, p, ap, size);
+    if(res)
+      die(res, "MPS_RESERVE_BLOCK");
+    res = dylan_init(p, size, exact_roots, NR_EXACT_ROOTS);
+    if(res)
+      die(res, "dylan_init");
+  } while(!mps_commit(ap, p, size));
+
+  return p;
+}
+
+static void *test(void *arg, size_t s)
+{
+  mps_space_t space;
+  mps_fmt_t format;
+  mps_root_t exact_root, ambig_root;
+  unsigned long i;
+  mps_word_t collections;
+
+  space = (mps_space_t)arg;
+
+  die(mps_fmt_create_A(&format, space, dylan_fmt_A()), "fmt_create");
+
+  die(mps_pool_create(&pool, space, mps_class_ams(), format),
+      "pool_create(ams)");
+
+  die(mps_ap_create(&ap, pool, MPS_RANK_EXACT), "BufferCreate");
+
+  die(mps_root_create_table(&exact_root, space,
+                            MPS_RANK_EXACT, (mps_rm_t)0,
+                            &exact_roots[0], NR_EXACT_ROOTS),
+                            "root_create_table(exact)");
+
+  die(mps_root_create_table(&ambig_root, space,
+                            MPS_RANK_AMBIG, (mps_rm_t)0,
+                            &ambig_roots[0], NR_AMBIG_ROOTS),
+                            "root_create_table(ambig)");
+
+  for(i=0; i<NR_EXACT_ROOTS; ++i)
+    exact_roots[i] = OBJNULL;
+
+  for(i=0; i<NR_AMBIG_ROOTS; ++i)
+    ambig_roots[i] = (mps_addr_t)rnd();
+
+  collections = 0;
+
+  i = 0;
+  while(collections < COLLECTIONS) {
+    unsigned c;
+    size_t r;
+
+    c = mps_collections(space);
+
+    if(collections != c) {
+      collections = c;
+      printf("\nCollection %u, %lu objects.\n",
+             c, i);
+      for(r = 0; r < NR_EXACT_ROOTS; ++r)
+        assert(exact_roots[r] == OBJNULL ||
+               dylan_check(exact_roots[r]));
+    }
+
+    if(rnd() & 1)
+      exact_roots[rnd() % NR_EXACT_ROOTS] = make();
+    else
+      ambig_roots[rnd() % NR_AMBIG_ROOTS] = make();
+    ++i;
+
+    r = rnd() % NR_EXACT_ROOTS;
+    if(exact_roots[r] != OBJNULL)
+      assert(dylan_check(exact_roots[r]));
+  }
+
+  mps_ap_destroy(ap);
+  mps_root_destroy(exact_root);
+  mps_root_destroy(ambig_root);
+  mps_pool_destroy(pool);
+  mps_fmt_destroy(format);
+
+  return NULL;
+}
+
+int main(void)
+{
+  mps_space_t space;
+  mps_thr_t thread;
+  void *r;
+
+  die(mps_space_create(&space), "space_create");
+  die(mps_thread_reg(&thread, space), "thread_reg");
+  mps_tramp(&r, test, space, 0);
+  mps_thread_dereg(thread);
+  mps_space_destroy(space);
+
+  return 0;
+}
diff --git a/mps/src/mpscams.h b/mps/src/mpscams.h
index e69de29bb2d..80c546f47b6 100644
--- a/mps/src/mpscams.h
+++ b/mps/src/mpscams.h
@@ -0,0 +1,14 @@
+/* impl.h.mpscams: MEMORY POOL SYSTEM CLASS "AMS"
+ *
+ * $HopeName: MMsrc!mpscams.h(MMdevel_poolams.1) $
+ * Copyright (C) 1997 Harlequin Group, all rights reserved.
+ */
+
+#ifndef mpscams_h
+#define mpscams_h
+
+#include "mps.h"
+
+extern mps_class_t mps_class_ams(void);
+
+#endif /* mpscamc_h */