UU(4)

NAME
uu - TU58/ DECtape II UNIBUS cassette interface

SYNOPSIS
options UUDMA
device uu0 at uba0 csr 0176500 vector uurintr uuxintr

DESCRIPTION
The uu device provides access to dual DEC TU58 tape cartridge drives connected to the UNIBUS via a DL11-W interface module.

The interface supports only block I/O to the TU58 cassettes (see physio(4)). The drives are normally manipulated with the arff(8) program using the ``m'' and ``f'' options.

The driver provides for an optional write and verify (read after write) mode that is activated by specifying the ``a'' device.

The TU58 is treated as a single device by the system even though it has two separate drives, ‘uu0’ and ‘uu1’. If there is more than one TU58 unit on a system, the extra drives are named ‘uu2’, ‘uu3’ etc.

NOTES
Assembly language code to assist the driver in handling the receipt of data (using a pseudo-dma approach) should be included when using this driver; specify ‘options UUDMA’ in the configuration file.

FILES
/dev/uu?
/dev/uu?a

DIAGNOSTICS

uu%d: no bp, active %d. A transmission complete interrupt was received with no outstanding I/O request. This indicates a hardware problem.

uu%d protocol error, state=%s, op=%x, cnt=%d, block=%d. The driver entered an illegal state. The information printed indicates the illegal state, the operation currently being executed, the I/O count, and the block number on the cassette.

uu%d: break received, transfer restarted. The TU58 was sending a continuous break signal and had to be reset. This may indicate a hardware problem, but the driver will attempt to recover from the error.

uu%d receive state error, state=%s, byte=%x. The driver entered an illegal state in the receiver finite state machine. The state is shown along with the control byte of the received packet.

uu%d: read stalled. A timer watching the controller detected no interrupt for an extended period while an operation was outstanding. This usually indicates that one or more receiver interrupts were lost and the transfer is restarted.

uu%d: hard error bn%d, pk_mod %o. The device returned a status code indicating a hard error. The actual error code is shown in octal. No retries are attempted by the driver.

ERRORS
The following errors may be returned:

[ENXIO]
    Nonexistent drive (on open); offset is too large or bad (undefined) ioctl(2) code.

[EIO]
    Open failed, the device could not be reset.

[EBUSY]
    Drive in use.

SEE ALSO
tu(4), arff(8)

HISTORY
The uu driver appeared in 4.2BSD.