EDOC108

Projet EUROGAM

Tape format

standard eurogam

Edition 1.4 18 janvier 1991

G.ZEHNACKER

SATD du Centre de Recherches Nucléaires CNRS-IN2P3 France 1 Introduction

The ’Tape Standard’ for ’Eurogam ’ is based on the ANSI standard . We propose it with the variable format D and the special structured data block .

2 Volume and file header label

The blocks VOL1, HDR1, HDR2, EOF1 , EOF2 and data file blocks should be written by the Data Acquisition software or by others softwares ( which save or restore data on/from the tape from/to memory or disk ). Other labels defined by the standards ( as UHLn and UTLn) should not be used.’

2.1 general structure

• a initialised tape contains :

• VOL1 **

• a tape with files contains: :

• VOL1 HDR1 HDR2 * — file — * EOF1 EOF2 ** nota1 : the file is definited later nota2 : * represents a ’tape mark’

2.2 block structure

’Volume label’ VOL1 • 1-4 : identifier set to VOL1

• 5-10 : volume name(6 characters)

• 11-37 : spaces

• 38-51 : user name( 14 characters ou spaces)

• 52-79 : spaces

• 80 : version 3 of the standard norme ’file header 1’ set to HDR1

• 1-4 : identifierHDR1

• 5-21 : file name ( 1 a 8 characters )

• 22-27 : the volume name ( the same as in VOL1

• 28-31 : 0001 ( in ASCII )

• 32-35 : file number ; begin with 1 then increase 1 with each file • 36-39 : generation number 0001

• 40-41 : version number set to 0

• 42-47 : date file creation ’ yyddd’ (’yy’ is the year , ’ddd ’ day number

• 48-54 : spaces

• 55-60 : 000000

• 61-73 : system code spaces

• 74-80 : spaces ’file header 2’ HDR2

• 1-4 : identifier set to HDR2

• 5 : variable format = D

• 6-10 : maximun number of characters per blocks; 8192 bytes

• 11-15 : length record - should be same as block length ( 8192 bytes)

• 16-50 : spaces

• 51-52 : set to 00

• 53-80 : spaces ’end file header 1’ EOF1

• 1-4 : identifier set to EOF1

• 5-54 : same that HDR1

• 55-60 : number of blocks in the file ( between 2 tapes marks )

• 61-80 : spaces ’end file header 2’ set to EOF2

• 1-4 : end file header 2 EOF2

• 5 -80 : same that HDR2

2.3 ’data block structure

the blocks allow to :

• 1-4 : block length in ASCII less than or equal 8192 bytes

• 5-12 : type of data bloc : FILEH,EVENTH,EVENTD,SPECTH,SPECTD,COMMENT • 13-20 : block counter in ASCII

• 21-end : the specific ’data’ A data file allow every kind of blocks .

’type of data bloc’ :

• FILEH for file definition

• COMMENT for comments,

• SCALER for scaling counter,

• PARAM for different parameters,

• EVENTH for events header,

• EVENTD for events data

• SPECTH for spectrum header

• SPECTD for spectrum data ’data block’

• a file can contain every spectra with different length

• the events blocks must be defined

• one logical block in one physical block

• for exabyte the length must be 8192 bytes

3 Other general proposals

• the file must be monovolume

• each ascii field are padded with trailing space

• empty field must be filled with spaces

• to decrease the number of tape marks on exabyte , we propose to save many spectra in one file