FCBSECT FCBSECT consists of the CMS File Control Elock (FCE) (used for file management under CMS), the simulated OS Job File Control Block (JFCB), Input/Output Block (lOB), and Data
Extent Block (DEB). FCBSECT is invoked via the CMSCE macro. FCBSECT is dynamically
allocated from CMS free storage each time the FILEDEF command is issued.
o FCBNEXT FCEPROC 8 FCBDD 10 FCBOP 18 FCBDSNIM 20 FCBDSTYP 28 FCBDSMD FCBITEM FCEBUFF 30 FCBBYTE FCEFORM FCBCOUT 38 FCBREID 1*2 FCBXTENT 40 FCBRECL I 1*3 I 1*4 FCEMEMBR 48 FCBMEMBR (cont.) FCBOSFST 50 FCBOSDSN PCER13 58 FCBKEYS . FCBPDS 60 JFCBftlSK 68 JFCBCRDT JFCBXPtT I 1*5 1*6 70 1*7 I A*8 JFCBUFL A*9 1*10 1//////1 1*11
78 JFCLIMCT (cont.) I JFCDSORG A*12 1*13 JFCBLKSI 80 JFCLRECL I A*14 I A*15 1///////////////////////////
88 DEBTCBAD SEBSIV 90 DEBOFLGS DEBCPITB 98 IOBNXTID IOBECB AO DEBDCBID IOBECBPT A8 IOBCSW BO IOBSTART IOBtCBPT Format of Location X'24' for Console Device 20 FCBIOOUT r
28 I FCBIOOUT (cont.) FCBIOBUF 30 I 1*16 I A*17 I FCBIOCNT 180 IBM VM/370 Data Areas and Control Block Logic
Hexadecimal Field
Displacement Name o
o
4
8 iO 18
18
18
18 20 24
2C 30 31
32
28
28 21 2C 30 34
36
38
3C
3D
3E 40 42
43
44
4C 50 54
58
5C 60 68
6B
FCBINIT DS FCBDOSL EQU FCBOS EQU FCBOPCB EQU FCBPERM EQU FCBBITCH EQU FCBCITML EQU FCBNEXT DS FCBPROC DS FCBDD DS FCBOP DS IHAJFCB DS JFCBDSNM DS FCBTIPID DS FCBDSNAM DS FCBDSTYP DS FCBPRPU EQU ORG FCBIOOUT DS FCBIOBUF DS FCBCONCR DS FCBCONMS DS FCBIOCNT DS FCBTBSP DS FCBDSMD DS FeBITE!! DS FCBBUFF DS FCBBYTE DS FCBFORM DS FCBCOUT DS FCBREID DS FCBDEV DS !!!!§ FCBCRT EQU FCBPCH EQU FCBDSK EQU FCBTAP EQU FCBCON EQU FCBRDR EQU FCBPTR EQU FCBDUM EQU FCBMODE DS FCBXTENT DS FCBRECL DS IOBIOFLG DS FCBDCBCT DS FCBMEMBR DS FCBOSFST DS FCBOSDSN DS FCBR13 DS FCBKEYS DS FCBPDS DS JFCBMASK DS JFCBCRDT DS JFCBXPDT DS ox
in FCBINIT --X'20'--- X'10' X'08' X'04' X'02' X'01' A
A
CL8 Ct8 OD OX OX CL8
CL8 FCBDSTYP+4 FCBDSTYP+4 CL8 1 Field Description, Contents, Meaning Initialization flag tytes
Concatenated DOSLIB data set FCB for OS formatted disk OPEN acquired this CMS block
Permanent control tlock Special batch data set Concatenated MACLIB data set AL3 (next CMSCB) A (special processing routine)
Data definition name eMS operation
Job file control block
44 bytes, data set name
Tape identification
Data set name
Data set type
printer/punch command list Special I/O command list
A(data buffer)
C A*16 Console color code X A*17 Console miscellaneous information
Length of data tuffer H OX CL2 H F
F
CL2
H
F
Tvo tytes for tape backspace
count
Data set mode Item identification number A(input/outFut tuffer)
Data count
I 1*1 File format: fixed/variatle records
Records per CMS physical block
Number of bytes actually read
Device type code in FCBDEV --28-----
24 20 16
12 X H
H X 8
4
o X 2F
F
F
F 1 A 8X 3C
3C
CRT Punch Disk
Tape
Console terminal
Reader
Printer DUllmy device 1*2 Mode: 1, 2, 3, 4, and 5 Number of items in extent DCB LRECL at open time 1*3 I/O flags 1*4 No. of DCBs using this FCB OS prs member name Pointer to CS FST Pointer to as dsname block Save area vector R13 ACDtS in-storage key table) A(PtS in-storage directory) Various mask bits
Data set creation date (YDD) Data set expiration date (YDD) FCBSECT Section 2. CMS rata Areas and Control Blecks 181
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