Amazing as it may seem, it is possible for the knowlegable, and intrepid user to change the size of a partition on the fly(as it were) in a manner which is transparent to the system, doesn't crash it or anything else interesting. For example one might like to have a resident library installed for testing, or create a temporary partition for a driver. As it turns out, system controled partitions(particularly GEN) are rather hard to change on the fly because the SET command either creates or deletes partitions, and does not allow a partition with active tasks to be deleted. What is realy needed is a SET /NEWTOP=parname:topval command which would allow the user to contract the size of a partition, provided no active tasks are present. Until the milenia arrives(or until we or DEC implement the command), the following method may be used to achieve exactly the same result Do an TAL on an INSTALLED task which is NOT active(it must not be active, checkpointed or anything else nasty, just installed). Take the second number (N) from the TAL display and OPEN N+16 The value displayed is the number of 64 byte blocks in that partition(say GEN). Change the value, and lo, GEN is a new size(hopefully smaller). Now with the freed up space one can do a SET /MAIN=newpar:newtop:(oldtop-newtop):SYS. When done with the partition, the user can do a SET /NOMAIN=newpar, and then, OPEN N+16 and restore the old value for GEN.