TRACK HEADER RECORD 0 4 8 10 20 <28 to FFF
< Hex --(5 4 6
8
A E 10 20 28
Dec --(5 4
6
8 10 11
16
32 40 THR 16 THRNDRD I THRNDRT IA IE THRNDRL I THRFLAG I THRHADD THROOO THR001 (Count Field or Data) > rielg_!!H 12!!§£riptiol! THR DC CL4'THR , ID of track header record
THRNDRD DC H'O' The number of count fields in the THR
THRNDRT DC H'O' The nuaber of 4K data records on taFe
THRDRL DC H'O' Length of the short (last) data record
THRFLAG DC XL1'0' Flag for THRFLAG SPECIAL EQU XI01'-----overflov THRHADD DC THROOO DC THR001 DC XL5'0' XL16'0' XL8'O' The home address reordered
Record 0 from the D1SD unit
Count field of the first record
Count fields and data
Figure 5-4. Track Header Record
Chapter 5. The DASD Dump Restore Program 107

lOB 0 IOBSTAT 4
8
C
14 IOBCLASS 18
1C 20 24 2S IOBFLAG 1 1 11 1 IOBOPT 115 I IOBTYPE IOBCYlP IOBMTCK IOBVSER 129 I 12 1 IOEUAtI IOBCCW IOBEBBOR IOBCSW 116 1 11A I t 1E 1 f 126 I Reserved IOEMB!C IOECYLA 11F IOBMODE I IOEATAPE for IBM use Status of IOE IOBDISP n!! for IOBSTAT IOBST EQU 1'80'-- I/O unit is to be started IOBSTACK EQU X'40' I/O error has been stacked IOBlAST EQU X'20' last lOB IOBNOPER EQU X'10' Device is not operational IOBCPVOl EQU X'OS' Unit is a CPVOL IOBOPEN EQU X'04' The lOB is open IOBSCRAT EQU X'02' The DASD device is a scratch volume IOBTPSWP EQU X'01' Switch to alternate tape in progress IOBOPT DS 11 lOB flags for IOBOPT IOBDEW EQU I'SO'---Wait for device end interrupt IOBERST EQU X'40' Stop on I/O error and wait for next interrupt IOBEEXIT EQU 1'20' Repeat CCW on error IOBSIO EQU X'10' Do not use Diagnose I/O Figure 5-5. lOB (Input/Output Block) Format (Part-1 of 2) 10S IBM V8/370 Service Routines Program Logic