DTCERT - A program to certify DECtapes on-line.

DTCERT will generate and write the timing marks on a DECtape.  Data is then
writen on the tape and verified.  All blocks are then zeroed and the directory
block is initialized.  All this is done without disrupting normal timesharing.

DTCERT requires a 500 or 600 series monitor running on a KA, KI or KL to be
configured with real time trapping enabled, one real time device and a free
PI channel.  When certifying DECtapes, DTCERT must have all the DECtape
drives on the controller.  DTCERT requires RATTRP and LOCK privilages to run.
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