+# VM memory size
+size_memory = 640*1024
+
+# Buffer sizes
+size_RS = 1024 # Return stack size
+size_PS = 1024 # Parameter stack size
+size_TIB = 4096 # Terminal input buffer size
+
+# VM registers
+RSP = 0 # Return stack pointer
+PSP =0 # Parameter/data stack pointer
+IP = 0 # Instruction pointer
+W = 0 # Working register
+X = 0 # Extra register
+
+RSP0 = 1
+PSP0 = RSP0 + size_RS
+here = PSP0 + size_PS + size_TIB # location of bottom of dictionary
+latest = 0 # no previous definition
+
+# The following array constitutes the memory of the VM. It has the following geography:
+#
+# memory = +-----------------------+
+# | Return Stack |
+# +-----------------------+
+# | Parameter Stack |
+# +-----------------------+
+# | Terminal Input Buffer |
+# +-----------------------+
+# | Dictionary |
+# +-----------------------+
+#
+# Note that all words (user-defined, primitive, variables, etc) are included in
+# the dictionary.
+#
+# Simple linear addressing is used with one exception: references to primitive code
+# blocks, which are represented as anonymous functions, appear the negative index
+# into the primitives array which contains only these functions.
+
+memory = Array{Int64,1}(size_memory)
+primitives = Array{Function,1}()