JTYPE
#define JBOOT (JTYPE|1) /* start a download in a window */
#define JTERM (JTYPE|2) /* return to default terminal emulator */
#define JMPX (JTYPE|3) /* currently running layers? */
#define JWINSIZE (JTYPE|5) /* inquire window size */
#define JTIMOM (JTYPE|6) /* timeouts in millisecs */
#define JZOMBOOT (JTYPE|7) /* JBOOT but wait for debugger to run */
#define JAGENT (JTYPE|9) /* control for both directions */
#define JTRUN (JTYPE|10) /* send runlayer command to layers cmd */
#define JXTPROTO (JTYPE|11) /* set xt protocol type */