t-att command

The t-att command attaches the tape unit or floppy disk drive to the current process unit and optionally assigns the block size to the tape I/O buffer.


t-att {blocksize} {(options}


blocksize (Integer number) Indicates the number of bytes in each block.
options u Unconditionally attaches the tape. It is strongly advised to verify that the tape is not actually being used before stealing it from another process.
z Unconditionally attaches the tape, except if the tape is attached to the transaction logger.


The types of devices that you can attach to are:

Floppy disks Can be set at any number between 20 and 512, but are usually set to 500 or 512. The default is 500.
1/2-inch tapes Can be set to anything between 512 and 16384, inclusive. The default is 8192.
SCTs Can be set to anything between 2048 and 16384 and must be a multiple of 512. The default is 16384.
8mm tapes Can be set to anything between 512 and 16384 and must be a multiple of 512.
Pseudo Floppy  

After attaching the device to the current process, all of the regular tape handling commands, like t-rew and t-fwd are available, even when using floppy disks. Floppy disks must be rewound before writing to or reading from them. Usually, this does not take long.

If the tape unit is attached to another line, the process displays the port that has it attached. The u option in the t-det command detaches the tape unconditionally, regardless of what it may be doing. This may be necessary if the transaction logger is enabled.

The t-att command should be used before any tape manipulation process, such as executing tape control commands, generating print file output to the tape using the t option in the sp-assign or sp-edit command, executing tape reads and writes in FlashBASIC, or generating tape output using the reformat and sreformat commands.

All tape manipulation processes on the system check for attachment, attach the tape if possible, generate the required message, and terminate if the tape is not available. The implied t-att uses the current tape block size specification and remains set until one of the following events occur:

  • Using the t-att command with a numeric argument.

  • Using the t-att command without a numeric argument.

  • Using any tape command which checks for tape attachment.

  • Executing the t-rdlbl command when a labeled tape is mounted. The tape block size is stored in labels written to tape. By reading a tape label through the t-rdlbl or t-read commands, the current block size is changed to the size stored in the label read.