User`s guide

FORMAT
surface, while the surface of the RX50 diskette is brown. The difference is apparent
when you compare them.
CAUTION
Do not format RX50 diskettes in an RX33 drive.
To format RX50 diskettes as RX33 diskettes is physically
possible. However, RX50 diskettes do not contain the
same oxide (storage medium) as RX33 diskettes and
cannot safely store 1.2 Mbytes of data. RX50 diskettes
therefore can randomly lose data if they are formatted
as RX33 diskettes.
Formatting Disks on the Professional Series Computer
Digital recommends formatting DW hard disks before they are used. If you boot
a Professional Series Computer from a diskette and the computer contains an
unformatted hard disk, a hardware diagnostic picture is displayed on the screen.
The diagnostic picture displays the number 010030 followed underneath by 000401,
indicating an unformatted hard disk. Software cannot be installed on the hard disk.
RT–11 boots from the diskette after displaying the diagnostic picture. Execute the
following sequence of commands to format and install the hard disk:
.FORMAT DW:
.INSTALL DW:
.LOAD DW:
.FORMAT/VERIFY:ONLY DW:
The command FORMAT DW: generates the informational message ?FORMAT-I-
Install DW.
Attempting to verify a hard disk with FORMAT/VERIFY:ONLY before formatting
an unformatted hard disk generates the error message ?FORMAT-F-Invalid device
for /VERIFY, or not formatted.
Formatting Extended Device Units
The FORMAT command recognizes device units greater than 7. So, for example, the
command FORMAT D10: is valid.
Formatting Based on CSR location
Formatting of devices at nonstandard addresses is supported and will occur
automatically, based on the CSR location specified in the device handler. For DU
devices, any supported number of controllers is allowed. For all other devices, only
a single controller is allowed.
Even though FORMAT accesses the hardware directly for some devices, FORMAT
uses the handler file contents to determine the CSR address.
126 RT–11 Command Descriptions