-word ic; /* instruction counter */
-word lastic; /* previous ic for redecoding after compact. */
-int opcode; /* opcode of L-code instruction */
-word a1, a2, a3; /* arguments of L-code instructions */
+/**
+ * instruction counter
+ */
+word ic;
+
+/**
+ * previous ic for redecoding after compact.
+ */
+word lastic;
+
+/**
+ * opcode of L-code instruction
+ */
+int opcode;
+
+/**
+ * arguments of L-code instructions
+ */
+word a1, a2, a3;
+
+/**
+ * \defgroup kernel variables for the running system:
+ */
+/**@{*/
+/**
+ * code and data memory size
+ */
+word memorysize = DEFMEMSIZE;
+
+/**
+ * pointers to current object
+ */
+word c1, c2;
+
+/**
+ * DISPLAY offset in process object
+ */
+word dispoff;
+/**
+ * indirect DISPLAY offset in process object
+ */
+word disp2off;
+
+/**
+ * DISPLAY address - physical addresses
+ */
+word display;
+/**
+ * DISPLAY address - indirect addresses
+ */
+word display2;
+
+/**
+ * main block object
+ */
+word mainprog;
+
+/**
+ * offset of variable main
+ **/
+word mnoff;