NAME

archive − Archive 1/4 inch Streaming Tape Drive

DESCRIPTION

The Archive streaming tape controller can control up to four 1/4 inch streaming tape drives. 

For a complete description of the Archive tape drive and its controller, refer to the Archive Intelligent Tape Drive Theory of Operation available from Archive corporation. 

CONFIGURATION

Each archive tape controller consumes eight consecutive locations in Multibus I/O space.  It does not consume any Multibus memory.  The first archive tape controller should be configured for Multibus I/O address 0x200; subsequent archive tape controllers should be configured at addresses 0x208, 0x210, and so on.  The archive tape controller should be set up to use interrupt level 1. 

To make a node in the /dev directory for a specific drive, change directory to /dev and type the command:

        MAKE  ar?

where ? is a number between 0 and 7.  The unit number is 0 through 3 (four units per controller), and the controller number is bit 3 of the number, thus:

FILES

/dev/rar[0-1]

IOCTL SYSTEM CALLS

The archive tape driver supports ioctl(2) such that calling programs may issue tape control requests (such as rewind) to the driver.  There are currently two ioctl requests available for this driver:

MTIOCTOP
is a request to perform a magnetic tape operation (other than read or write). The names of the magnetic tape operations are detailed below. When this request is used, the caller must pass a structure to the request.  The layout of this structure is defined in mtio.h.

MTIOCGET
is a request to return the status of the tape drive or controller.

Note: that ioctl calls to this device must be made to /dev/rar, that is, the raw device.

The definitions for the ioctl request can be found in mtio.h, and are as follows:

MTWEOF
write an end-of-file record

MTFSF
forward space file

MTBSF
backward space file (currently not implemented).

MTFSR
forward space record (currently not implemented).

MTBSR
backward space record (currently not implemented).

MTREW
rewind tape.

MTOFFL
rewind and put the drive offline -- currently this is the same as rewind.

MTNOP
no operation, sets status only

MTTENSE
Retension tape -- wind forward then rewind

MTERASE
Data Security Erase -- erase whole tape

LIMITATIONS

An open request for a new drive will fail if the current drive is not positioned at beginning of tape (BOT). 

Tape must be at beginning of tape (BOT) or at a filemark before a read status IOCTL command can be issued. 

Physical I/O (to the raw device) is limited to blocksizes of ≤ 20480 bytes. 

When using the raw device, the number of bytes in any given transfer must be a multiple of 512 bytes.  If it is not, the device driver returns an error. 

The non-raw blocked (cooked) device is not available. 

7th Edition  —  11/23/82