+# Built-in variables
+
+nextVarAddr = 1
+RSP0 = nextVarAddr; nextVarAddr += 1
+PSP0 = nextVarAddr; nextVarAddr += 1
+HERE = nextVarAddr; nextVarAddr += 1
+LATEST = nextVarAddr; nextVarAddr += 1
+
+memory[RSP0] = size_BIVar # bottom of RS
+memory[PSP0] = memory[RSP0] + size_RS # bottom of PS
+TIB = memory[PSP0] + size_PS # address of terminal input buffer
+memory[HERE] = TIB + size_TIB # location of bottom of dictionary
+memory[LATEST] = 0 # no previous definition