F_BREADY
if (!(t->flags & (F_AREADY|F_BREADY)))
if (t->flags & F_BREADY) {
t->flags &= ~F_BREADY;
t->flags &= ~(F_BREADY|F_SOFCHECK1|F_SOFCHECK2);
t->flags |= ab ? F_BREADY : F_AREADY;
t->flags &= ~(F_AREADY|F_BREADY|F_AINPROG|F_BINPROG|F_LOWSPEED);