DMSCCB DMSCCE describes all fields of a DOS Co.mand Control Block (CCB). This DSECT is used by DMSXCP to map the CCB specified by a user for an SVC 0 (EXCP) and passes the address of CCB to DMSXCP. I o I A*1 1*2 A*3 1*4 I A*5 A*6 1---------------------------------------------------------
8 I 1*7 CCBCCW A*8 CCECSW 10 I CCBLDITB CCBLCCWE 1--------------------------------------------------------
18 1///////////////////////////1 A*9 CCEFSCCW 1----------------------------------------------------- 20 I CCBRDCCW CCBWTCCi 1------------------------------------------------- 28 I CCBLWCCW 1///////////////////////////
1------,--------------------------------------------------- 30 1///////////////////////////1/////////////////////////// 1--------------------------------- 38 I CCBNCCB 1///////////////////////////
Hexadecimal Field
Displacement Name Field Description, Contents, Meaning o
o
2
2
3 CCBST CCBD CCBL-Elf CCBCNT EQU EQU DS DS CCBERMIP DS CCBCOM1 DS
Bits defined CCBWAIT--EQU CCBEOF EQU CCBIOERR EQU CCBERROK EQU CCBRDC EQU CCBPDE EQU CCBDCV EQU CCBUERR EQU CCBCOM2 DS !!i!§ CCBDCCNT EQU CCBTRKOV EQU CCBEOC EQU CCBDC EQU CCBNOREC EQU CCBRETRY EQU CCBVER EQU CCBCC EQU *
* OCL16 XL2 OXL4 XL1 in CCBCOM1 --X'80'-- X'40' X'20' X'10' X'08' X'04' X'02' X' 01' XL1 in CCBCOM2 -X'80'-- X'40' X'20' X'10' X'08' X'04' X'02' X' 0 l' Start CCB Command control block lIapcftherOS CCB Residual count
Four bytes used to check errors 1*1 Communications byte 1 1*2 Traffic bit (set at CE) End cf file Unrecoverable I/O error AcceIt unrecoverable error
Return data checks Post at device end
Return data check RD/CHK User error routine Communications byte 2
Data check in count area
Track overrun
End cf cylinder
Data check
No record found
Retry no record found Verify error Command chain (retry)
162 IBM VM/370 Data Areas and Control Block Logic

Hexadecimal Field
Displacement Name
4
5
6
6
7
8
9 C D 10 14
18 1C 1D 20 24
28 2C CCBCSW1 DS !!i!.§ CCBATTN EQU CCBSTMOD EQU CCBCUE EQU CCBBUSY EQU CCBCE EQU CCBDE EQU CCBUC EQU CCBUE EQU CCBCSW2 DS Bits defined --- ------ CCBPCI EQU CCBILEN EQU CCBPROGM EQU CCBPROT EQU CCBCHAND EQU CCBCHANC EQU CCBICTRL EQU CCBCHAIN EQU CCBSYMU DS CCBSUCLS DS CCBSUNUM DS CCBLIOBS DS CCBCCW DS CCBCOM3 DS CCBAPEND EQU CCBCSW DS CCBLDATB DS CCBLCCWB DS DS CCBUFLGS DS !!i!.§ CCBUEAIC EQU CCBUEAC EQU CCBURDCW EQU CCBRPS EQU CCBFSCCW DS CCBRDCCW DS CCBWTCCW DS CCBLWCCW DS DS XL1 in CCECSW1 --X'8'O'-- X'40' X'20' X'10' X'08' X'04' X'02' X'01' XL1 in CCBCSW2 --x=ao:-- X'40' X'20' X'10' X'08' X'04' X'02' X'01' OXL2 XL1 XL1 XL1 XL3 XL1 X'40' XL3 A
A
F X in CCEUFLGS -- X'SCj"i--- X'40' X'20' X'10' XL3 F
F
F
3F
Field Description, Contents, A*3 csw status tit 1
Attention Status modifier Control unit end
Busy Channel end
Device end Unit check Unit exception
A*4 CSW status tit 2 program-controlled interruFt Incorrect length Program check Protection check Channel data check Channel central check
Interface control check Chaining check Symbclic unit (SYSUN) A*5 U - LUB class
A*6 N
- LUB numter within class 1*7 Reserved for tleES Pointer to start of channel Frogram A*8 Communication byte 3 APFendage exit at interrupt Pointer to csw or to appendage routine Address of last data block
Address of last CCi tlock
Reserved for IBM use
A*9 I/O manager CCB flags
Error analysis in control
Errer analysis complete
Read CCW active RPS channel program candidate Save area fer first CCi address
Address of first read CCW Address of first write ccw Address of the last write CCW Reserved for IBM use DMSCCB Note: CCBLWCCW chain field must have the same displacement as does FCECHIIN In-FCDB and also BKPFSTBK in BKPRD 38 3C CCBNCCB DS DS A
F
Address of next CCB block Reserved for IBM use Section 2. CMS tata Areas and Centrol Blocks 163