Quantum Audio STT2401A 사용자 설명서

Page 116 

Seagate Travan 40 Product Manual 

Frames are numbered indirectly using the 26 most significant bits of the Physical 
Block Address. Frame operation is controlled by the drive and generally invisible to 
the host. Frames are used primarily as a means to control the error correction 
operations. 

Frames can be overwritten with new data frames or an End-of-Data (EOD) frame. 
Append operations can only begin at EOD. 

An underrun is not allowed in the middle of a frame, regardless of the frame type. 
Filler blocks can be used to complete a frame as long as they are not used interior to 
a logical block. 

A frame that cannot be completed on one track is rewritten in its entirety at the 
beginning of the following track. Frames are not split around corner turns. 

The general frame layout—470 data blocks and 40 ECC blocks—is illustrated in the 
table below. 

Data 
Block  
0 

Data 
Block 
1 

Data 
Block 
2 

... 

Data 
Block 
470 

ECC  
Block 
0 

ECC  
Block 
1 

... 

ECC 
Block 
39 

The four types of frames are as follows: 

• 

Data frames contain data and information blocks in addition to ECC blocks. 

• 

The Media Header frame contains only Media Header blocks and ECC blocks. 
This frame is recorded as the first frame on the Directory Track. 

• 

Track ID frames are recorded as part of the pre-formatting process of the 
cartridge. These frames are easily distinguished from other frame types because 
they reside entirely outside of the data region of the tape. 

• 

An EOD frame is an absolute indicator of the end of the recorded data. It is 
recorded after the last frame containing host data upon terminating a Write 
process.