get "iohdr"

manifest $( initial.burst.count = 40
            act.timer           = 1010
            act.die             = act.end
            act.transmit        = 1008
            act.receive         = 1009
            act.findfreeport    = 998
            act.reserveport     = 997
            act.releaseport     = 996
            act.cancel.rx       = 980
            retry.ticks         = 2
            e.txpkt             = 13
            e.rxpkt             = 14
            retry.count         = 40
            rtninfo.ether       = 1
         $)

manifest $( blockoff       =    16
            e.len1         =    5 + blockoff
            e.len2         =    6 + blockoff
            e.data         =    7 + blockoff
            e.dest         =    blockoff
            e.source       =    4 + blockoff
            e.port         =    1 + blockoff
            e.port1        =    1 + blockoff
            e.port2        =    2 + blockoff
            e.port3        =    3 + blockoff
         $)