Aug. 1. i979 20.2 IBM VM/3 7 0 Data Areas and Control Block Logic

Page of SY20-0884-3 As Updated Aug. 1, 1979 by TNL SN25-0497 IOBLOR IOBLOK cont.ains information required to perform I/O operations. The I/O request
initiator for the I/O operation is either a CP-initiated or virtual machine-initiated eVent. There are five pointers to the IOBLOK: RCHFIOB field of the RCHBLOK, ReHFIOB
field of the RCUBLOK, RDEVAIOB field of the RDEVBLOK, VDEVFIOB field of the VDEVBLOK, RDEVF10B field of the RDEVBLOK. 0 8 10 18 20 28 30 38
Hexadecimal
Displacement
------------ 0 2
3 r- I 10BRADD 11* 1 11*2 10BLINK I IOBFPNT IOBBPNT 10BCYL 10BVADD IOBMISC IOBUSER IOBIRA IOBCAW 10BRCAW IOBCSW IOBIOER 1*3 1*4 I 1*5 I RSV2 Field
Name 10BRADD DS 1H IOBFLAG DS 1X Bii§ Q.§iined in lOB FLAG IOBCP EQU --X'80'-- IOBRSTRT EQU X'40' IOBSPLT EQU X'20' 10BPAG EQU X' 10' TI"IDD"!:1Tr"n EQU VIAO. ..,L.v.uL\.uJ...l,"", U ,A-VU- IOBERP EQU X'04' lOB RES EQU X'02' 10BHVC EQU X
C 01; IOBSTAT DS 1X B:li§ Q.§iined i!! IOBFATAL EQU X'80' IOBFLT EQU X'40' IOBPATHF EQU X'20' IOBMINI EQU X'08' IOBALTSK EQU X'04' IOBCC3 EQU X'03' IOBCC 2 EQU X'02' IOBCC1 EQU X'01' IOBCCO EQU X'OO' 1OBMISC2 10BCUBSY Field Description, Contents, Meaning
Real device address for SIO 1*1 IOBLOK flags
CP-generated I/O operation
Restarted operation - IOBRCAW DASD - CP split seek operation IOBLOK created for paging I/O Control unit released at initiation I/O task is under control of ERP I/O task has been reset I/O initiated via DIAGNOSE instruction
1*2 IOBLOK status Unrecoverable error in this I/O operation IOBLOK queued pending completion of a MSS cylinder fault Path is fixed, use IOBRADD value
This is a mini-IOBLOK DASD channel program has seek to alternate
track
Processing CC 3, not available
Processing CC 2! channel busy
Processing CC 1, CSW stored
Processing I/O interrupt
section 1. CP Data Areas and Control Blocks 25