BAD or the badblock locator utility is used to determine if bad blocks exist on a disk volume and to record the locations for use by backup and restore utilites and the INITALIZE task. The general form of the command line is: device:/switches Switches legal for both task and standalone versions are:- /LI List bad block numbers as the are encountered /MAN Enter manual mode /OVR Ignore/override last track on volume /RETRY Force I/O driver to retry bad blocks /UPD Enter update mode Switches legal only for the standalone versions are:- /CSR=nnnnnn For standalone BAD set CSR for device /VEC=nnn For standalone BAD, set vector for device /WCHK For standalone BAD, do I/O with writecheck For help on a given switch type "HELP BAD " 2 CSR /CSR=nnnnnn (Standalone BAD only) This switch alters the CSR address of the device so that it conforms to that of the device in the user's system. 2 LIST /LI Causes all bad blocks to be printed by number in decimal on your terminal. Bad blocks are listed as BAD perform pattern checks on each block. 2 MANUAL /MAN Causes BAD to first prompt you for bad block information and then to perform data pattern checking. The prompt is of the form:- BAD>LBN(S)= to which the user should reply with blocknum<:number><,blocknum<:number><,...>> where number specifies the number of sequential bad blocks starting at the specified block number blocknum. Both blocknum and number default to decimal values unless the value is preceded by a number sign (#) when it is considered an octal value. If just a carriage return is entered in response to the prompt, BAD will list all the sequences in the bad block descriptor file in decimal. To terminate the sequence type or <^Z> in response to the prompt. 2 OVR /OVR This switch causes BAD to ignore last track information and write a bad block descriptor file on the last good block before the last track. This is usually used if the reliability of the last track on last-track devices is in doubt. 2 RETRY /RETRY This switch causes BAD to attempt a recovery of hardware errors via the device driver. This also means that soft errors, such as an ECC correctable error, will be recovered and the block will be marked as good. 2 UPDATE /UPDATE This switch causes BAD immediately to read the bad block descriptor file and then prompt you for additional bad block input. The prompt is of the form:- BAD>LBN(S)= to which the user should reply with blocknum<:number><,blocknum<:number><,...>> where number specifies the number of sequential bad blocks starting at the specified block number blocknum. Both blocknum and number default to decimal values unless the value is preceded by a number sign (#) when it is considered an octal value. If just a carriage return is entered in response to the prompt, BAD will list all the sequences in the bad block descriptor file in decimal. To terminate the sequence type or <^Z> in response to the prompt. 2 VECTOR /VEC=nnn (Standalone BAD only) This switch alters the interrupt vector for a device so that it conforms to the vector address of the device in the user's system. 2 WCHK /WCHK (Standalone BAD only) This switch causes a write check operation to occur after each write operation. The switch is not available for devices DT, DX or DY.