diff --git a/mps/qa/function/12p.c b/mps/qa/function/12p.c
new file mode 100644
index 00000000000..c02e2e83d16
--- /dev/null
+++ b/mps/qa/function/12p.c
@@ -0,0 +1,213 @@
+/* TEST_HEADER
+ summary = lots of APs with interleaved reserve and 2-stage commit
+ language = c
+ link = testlib.o newfmt.o
+END_HEADER
+*/
+
+/*
+   This test needs some explanation. The object 'cells' contains
+   NCELL references to other objects. NAPS allocation points
+   are created. At each step, we choose one and nudge it on
+   a little. Each allocation point goes through the following
+   cycle of steps: reserve, init, begin commit, end commit.
+   At the init step, each reference in the reserved object is
+   set to point randomly to one of the objects referenced by
+   cells or (with probability PNULL) to NULL. If commit fails,
+   the object is thrown away. If it succeeds, it is written into
+   a random reference in cells. Repeat.
+
+   Because it has to deal directly with reserve and commit,
+   this test can't use the nice functions provided by newfmt
+   all the time.
+*/
+
+#include "testlib.h"
+#include "mpscamc.h"
+#include "newfmt.h"
+
+void *stackpointer;
+
+#define NCELLS 100
+#define NAPS 100
+#define PNULL (ranint(100)<25)
+#define NUMREFS (ranint(20))
+#define BLAH 0
+
+mps_ap_t ap[NAPS];
+size_t s[NAPS];
+int nrefs[NAPS];
+int ap_state[NAPS];
+
+static void test(void)
+{
+ mps_space_t space;
+ mps_pool_t pool;
+ mps_thr_t thread;
+ mps_root_t root;
+
+ mps_fmt_t format;
+ mycell *cells;
+
+ int h,i,j,k,l;
+ mycell *p[NAPS];
+ mycell *pobj;
+ size_t bytes;
+ size_t alignment;
+ mps_addr_t q;
+ int nextid = 0x1000000;
+
+/* turn on comments about copying and scanning */
+ formatcomments = BLAH;
+ fixcomments = BLAH;
+
+ cdie(mps_space_create(&space), "create space");
+
+ cdie(mps_thread_reg(&thread, space), "register thread");
+
+ cdie(
+  mps_root_create_reg(&root, space, MPS_RANK_AMBIG, 0, thread,
+   mps_stack_scan_ambig, stackpointer, 0),
+  "create root");
+
+ cdie(
+  mps_fmt_create_A(&format, space, &fmtA),
+  "create format");
+
+ cdie(
+  mps_pool_create(&pool, space, mps_class_amc(), format),
+  "create pool");
+
+ for (i=0; i<NAPS; i++)
+ {
+ die(mps_ap_create(&ap[i], pool, MPS_RANK_EXACT), "create ap");
+ ap_state[i] = 0;
+ }
+
+cells = allocone(ap[0], NCELLS);
+
+/* ap_state can have the following values:
+ 0 before reserve
+ 1 after reverse
+ 2 after init
+ 3 after I=A
+ 0 after commit
+*/
+
+ for(h=0; h<100; h++)
+ {
+ comment("%i of 100", h);
+ comment("%i collections", (int) mps_collections(space));
+
+ for(j=0; j<1000; j++)
+ {
+ i = ranint(NAPS);
+
+ switch (ap_state[i])
+ {
+  case 0:
+   nrefs[i] = NUMREFS;
+   bytes = offsetof(struct data, ref)+nrefs[i]*sizeof(struct refitem);
+   alignment = MPS_PF_ALIGN;
+   bytes = (bytes+alignment-1)&~(alignment-1);
+   s[i] = bytes;
+   die(mps_reserve(&q, ap[i], s[i]), "reserve: ");
+   p[i] = q;
+   p[i]->data.tag = 0xD033E2A6;
+   p[i]->data.id = nextid;
+   ap_state[i] = 1;
+   commentif(BLAH, "%i: reserve %li at %p", i, nextid, q);
+   nextid +=1;
+   break;
+  case 1:
+   commentif(BLAH, "%i: init %li", i, p[i]->data.id);
+   p[i]->data.tag = MCdata;
+   p[i]->data.numrefs = nrefs[i];
+   p[i]->data.size = s[i];
+   ap_state[i] = 2;
+   for (k=0; k<nrefs[i]; k++)
+   {
+    if PNULL
+    { p[i]->data.ref[k].addr = NULL;
+      p[i]->data.ref[k].id   = 0;
+    }
+    else
+    {
+     l = ranint(NCELLS);
+     pobj = getref(cells, l);
+     p[i]->data.ref[k].addr = pobj;
+     p[i]->data.ref[k].id = (pobj==NULL ? 0 : pobj->data.id);
+    }
+    commentif(BLAH, "    ref %i -> %li", k, p[i]->data.ref[k].id);
+   }
+   break;
+  case 2:
+   commentif(BLAH, "%i: begin commit %li", i, p[i]->data.id);
+   ap[i]->init = ap[i]->alloc;
+   ap_state[i] = 3;
+   break;
+  case 3: case 4: case 5: case 6: case 7: case 8: case 9:
+   ap_state[i]+=1;
+   break; 
+  case 10:
+   commentif(BLAH, "%i: end commit %li", i, p[i]->data.id);
+   q=p[i];
+   if (ap[i]->limit != 0 || mps_ap_trip(ap[i], p[i], s[i]))
+   {
+    l = ranint(NCELLS);
+    setref(cells, l, q);
+    commentif(BLAH, "%i -> %i", i, l);
+   }
+   ap_state[i] = 0;
+   break;
+ }
+ }
+ checkfrom(cells);
+ }
+
+ comment("Finished main loop");
+
+ for (i=0; i<NAPS; i++)
+ {
+  switch (ap_state[i])
+  {
+   case 1:
+    commentif(BLAH, "%i init", i);
+    p[i]->data.tag = MCdata;
+    p[i]->data.numrefs = 0;
+    p[i]->data.size = s[i];
+   case 2:
+    commentif(BLAH, "%i begin commit", i);
+    ap[i]->init = ap[i]->alloc;
+   case 3:
+    commentif(BLAH, "% end commit", i);
+    (void) (ap[i]->limit != 0 || mps_ap_trip(ap[i], p[i], s[i]));
+  }
+  mps_ap_destroy(ap[i]);
+ }
+
+ mps_pool_destroy(pool);
+ comment("Destroyed pool.");
+
+ mps_fmt_destroy(format);
+ comment("Destroyed format.");
+
+ mps_root_destroy(root);
+ comment("Destroyed root.");
+
+ mps_thread_dereg(thread);
+ comment("Deregistered thread.");
+
+ mps_space_destroy(space);
+ comment("Destroyed space.");
+}
+
+int main(void)
+{
+ void *m;
+ stackpointer=&m; /* hack to get stack pointer */
+
+ easy_tramp(test);
+ pass();
+ return 0;
+}
diff --git a/mps/qa/function/26.c b/mps/qa/function/26.c
new file mode 100644
index 00000000000..c41c043dbba
--- /dev/null
+++ b/mps/qa/function/26.c
@@ -0,0 +1,56 @@
+/* TEST_HEADER
+ summary = try to allocate as large an object as will succeed
+ language = c
+ link = testlib.o
+END_HEADER
+*/
+
+#include "testlib.h"
+#include "mpscmv.h"
+
+mps_space_t space;
+mps_pool_t pool;
+mps_addr_t q;
+
+static mps_res_t trysize(size_t try) {
+ mps_res_t res;
+
+ die(mps_pool_create(&pool, space, mps_class_mv(),
+  1024*32, 1024*16, 1024*256), "pool");
+
+ comment("Trying %x", try);
+
+ res = mps_alloc(&q, pool, try);
+ mps_pool_destroy(pool);
+
+ comment("%s", err_text(res));
+
+ return res;
+}
+
+static void test(void) {
+ size_t inf, sup, try;
+
+ die(mps_space_create(&space), "create");
+
+ inf = 0;
+ sup = 1024*1024*1000; /* i.e. 1 gigabyte */
+
+ while (sup-inf > 1) {
+  try = inf + (sup-inf)/2;
+  if (trysize(try) == MPS_RES_OK) {
+   inf = try;
+  } else {
+   sup = try;
+  }
+ }
+
+ for (try = inf-4; try < inf+4; try++)
+  (void) trysize(try);
+}
+
+int main(void) {
+ easy_tramp(test);
+ pass();
+ return 0;
+}