diff --git a/PDP10/kx10_dp.c b/PDP10/kx10_dp.c
index 3b3f075..08e43ac 100644
--- a/PDP10/kx10_dp.c
+++ b/PDP10/kx10_dp.c
@@ -715,7 +715,7 @@ t_stat dp_svc (UNIT *uptr)
                 CLR_BUF(uptr);
            }
            if (r)
-               sim_activate(uptr, 15);
+               sim_activate(uptr, 25);
            else {
                uptr->STATUS &= ~(SRC_DONE|END_CYL|BUSY);
                uptr->UFLAGS |= DONE;