Page of SY20-0884-3 As Updated Aug. 1, 1979 by TNL SN25-0497 RCUBLOK RCUBLOK provides control and status information on a defined real control unit. Linkages
are provided to queued IOBLOKs. The ARIOCU field of the PSA points to the first RCUBLOK,
which is generated in contiguous storage.
Hexadecimal
o
8 10 18 20 28 30 Displacement
------------ 0 2 4 5
6
8
C 10 10 RCUADD RCULOCK R*1 I R*2 RCUQCNT RCUFIOB RCULIOB RCUCHA RCUCHB RCUCHC RCUCHD RCURSTQ RCUOPER RCUCUBSY RCURSV1 RCUDVTBL (Variable Length) L- ______________________________________________________ . ___________ Field
Name Field Description, Contents, Meaning
--------------------------------------
RCUADD DS 1H Control unit address RCULOCK DS 1H Control unit lock RCUSTAT DS 1X R*1 Control unit status defined in RCUSTAT RCUBUSY EQU -X'80'--- Control unit busy RCUSCED EQU X'40' lOB scheduled on control unit RCUDISA EQU X'20' Control unit disabled RCUCHAOF EQU X'OS' RCUCHA to RCHBLOK path is not available RCUCHBOK EQU X'04 ' RCUCHB to RCHBLOK path is not available RCUCHCOF EQU X'02' RCUCHC to RCHBLOK path is not available RCUCHDOF EQU X'01' RCUCHD to RCHBLOK path is not available RCUTYPE DS 1X R*2 Control unit type in RCUTYPE RCUSHRD EQU --X'80-' --
This control unit can be attached to only one subchannel RCUSUB EQU X'40' This is a subordinate control unit RCU2703 EQU X'03' TCU is a 2703 RCU2702 EQU X'02' TCU is a 2702 RCU2701 EQU X'01' TCU is a 2701 RCUQCNT DS 1H Number of IOBLOKs queued off control unit RCUFIOB DS 1F Pointer to first IOBLOK queued RCULIOB DS 1F Pointer to last IOBLOK queued
RCUCHA DS 1F Pointer to RCHBLOK -path A ORG RCUCHA RCUPRIME DS 1F Pointer to the primary control unit
82 IBM VM/370 Data Areas and Control Block Logic

Hexadecimal
14
18
iC 20 24
28
2C 30 Field :RCUCHB DS RCUCHC DS BCUCHD DS RCURSTQ DS RCUOPER DS RCUCUBSY DS RCURSV1 DS RCUDVTBL DS RCUSIZE EQU Page of SY20-0884-3 As Updated Aug. 1, 1979 by TNL SN25-0497 RCUBLOK 1F
1F
iF
1F
1F
1F
1F
16H Field Description, Contents, Heaning Pointer to RCHBLOK -path B
Pointer to RCHBLOK -path C
Pointer to RCHBLOK -path D Address of control unit to be restarted IOBLOK operational on control unit time
Queue of control unit busy IOBLOKs Reserved for IBM use
Devices attached - RDVSTART index
(The index values must be multiplied
by 8 and added to the beginning of the RDEVBLOK table (ARIODV).) (*-RCUBLOK)/8 RCUBLOK size in doublewords (X'08') Section 1. CP Data Areas and Control Blocks 83