removed p! and p@ and added 'mem' that just pushes the addr os the persistent memory on to the stack and than you can write/read using standard ! and @ nd write at an offset uaing pointer arithmetic

alloc.sl

@@ -0,0 +1,36 @@
+import stdlib/stdlib.sl
+import stdlib/io.sl
+
+: alloc
+    0      # addr hint (NULL)
+    swap   # size
+    3      # prot (PROT_READ | PROT_WRITE)
+    34     # flags (MAP_PRIVATE | MAP_ANON)
+    -1     # fd
+    0      # offset
+    mmap
+;
+
+: free
+    munmap drop
+;
+
+: test-mem-alloc
+    4096 alloc dup 1337 swap !   # allocate 4096 bytes, store 1337 at start
+    dup @ puti cr                # print value at start
+    4096 free                    # free the memory
+;
+
+struct: Point
+    field x 8
+    field y 8
+;struct
+
+: main2
+    32 alloc           # allocate 32 bytes (enough for a Point struct)
+    dup 111 swap Point.x!
+    dup 222 swap Point.y!
+    dup Point.x@ puti cr
+    Point.y@ puti cr
+    32 free            # free the memory
+;