IBM Magstar 3494 manual Bytes Description Use

Table 32. HDR1
Bytes	Description	Use
0±2	Label Identi®er	Contains ªHDRº
3	Label Number	Contains ª1º
4±20	Data Set Identi®er	Retained, Not checked
21±26	Data Set Serial Number	Retained, Not checked
27±30	Volume Sequence Number	Retained, Not checked
31±34	Data Set Sequence Number	Retained, Not checked
35±38	Generation Number	Retained, Not checked
39±40	Version Number	Retained, Not checked
41±46	Creation Date	Retained, Not checked
47±52	Expiration Date	Retained, Not checked
53	Data Set Security	Retained, Not checked
54±59	Block Count	Must be ª000000º
60±72	System Code	Retained, Not checked
73±79	Reserved	Retained, Not checked
Table 33. HDR2
Bytes	Description	Use
0±2	Label Identi®er	Contains ªHDRº
3	Label Number	Contains ª2º
4	Record Format	Retained, Not checked
5±9	Block Length	Must be equal to the Record Length for the Export List File, Import List
		File and Status File. Retained, not checked for the Reserved ®le.
10±14	Record Length	Must be 80 bytes for the Export List File, Import List File and Status
		®le. Retained, not checked for the Reserved ®le.
15	Tape Density	Retained, Not checked
16	Data Set Position	Retained, Not checked
17±33	Job/Job Step Identi®cation	Retained, Not checked
34±35	Tape Recording Technique	Retained, Not checked
36	Control Character	Retained, Not checked
37	Reserved	Retained, Not checked
38	Block Attribute	Must be ª000000º
39±46	Reserved	Retained, Not checked
47	Checkpoint Data Set	Retained, Not checked
	Identi®er
48±79	Reserved	Retained, Not checked

312Magstar 3494 Tape Library Operator Guide