3. The value of the VDEVPLAG field (displacement X'01') indicates the
device-dependent information:
value of X'SO' X'SO' X'40' X'40' X'40' X'20' X'10' X'10' X'OS' X'OS' X'04' X'02' X'02' X'01' £2!!m!!§-- DASD -- read-only device Virtual 2701/2702/2703 device line enabled D1SD -- TDISK space allocated by CP Virtual 2701/2702/2703 device line connected
Console --activity spooled DASD -- 2311 device simulated on top half of 2314 DASD -- 2311 device simulated on bottom half of 2314
Console and spooling device --processing first ccw DASD -- executing standalone seek
Console --delay spooling Virtual device is being attached RESERVE/RELEASE are valid CCi operation codes
present attention with a single interrupt Virtual device sense bytes present
4. The VDEVCSW field (displacement X'08') contains the virtual channel
status word for the last interrupt.
5. The VDEVREAL field (displacement X'24') contains the pointer to the
real device block, 6. The VDEVIOB field (displacement X'34') contains the pointer to the
active IOBLOK. 7. For console devices, the value of the VDEVCFLG field (displacement X'26') describes the virtual console flags: Value of X'SO' X'40' X'20' X'10' X'OS' COllments user-SIgnalled attention tee many times
Last CCi processed was a TIC Data transfer occurred during this channel program Virtual console function in progress
Automatic carriage return on first read
8. For spooling devices, the value of the VDEVSFLG field (displacement X'21') describes the virtual spooling flags: Value of X'SO' X'40' X'20' X'10' X'OS' X'OS' X'04' X'02' X'02' X'01' comments spcor-output -- transferred to VSPXXUSR Spool device --continuous operation
Hold output --save input
spool output --for user and distribution
spool input --set unit exception at EOP Terminal output required for spooled console
Device closed by console function Spool output --purge file at close
spool input --device opened by DIAGNOSE Spool output -- DMKVSP entered via SVC Part 1. Debugging with VM/370 55

9. For output spooling devices, the VDEVEXTN field (displacement X'10') contains the pointer to the virtual spool extension block, VSPXBLOK. 10. The value of the VDEVFLG2 field (displacement X'38') describes the
Reserve/Release flags. Value of X'80' X'40' X'20' X'10' Comments Process-virtual Reserve/Release commands
Minidisk reserved by VDEVUSER VDEVBLOK to get device end when minidisk released Virtual I/O waiting for release on minidisk
11. For Reserve/Release minidisks, VDEVRRB (displacement X'3C') contains
the address of the VRRBLOK. The address of the first RCHBLOK is found in the ARIOCH field
(displacement X'3B4') of the PSA (Prefix Storage Area). General register
6 contains the address of the active RCHBLOK. Examine the following
fields:
1. The real channel address is found in the RCHADD field (displacement X'OO') • 2. The value of the RCHSTAT field (displacement X'04') describes the
status of the real channel. Value of RCHSTAT Comments X'80'--ChanneI-busy X'40' lOB scheduled on channel X'20' Channel disabled X'01' Channel dedicated
3. The value of the RCHTYPE field (displacement X'05') describes the
real channel type: Value of X'80' Selector channel X'40' Block multiplexer channel X'20' Byte multiplexer channel X'01' S/370 type channel (S/370 instruction sUFport) 4. The RCHFIOB field (displacement X'08') is the pointer to the first IOBLOK in the queue and the RCHLIOB field (displacement X'OC') is
the pointer to the last IOBLOK in the queue.