| |
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure CHPBK SPXTAPE Channel Program Block
Reserve space for the base IORBK
0000 0 Dbl-Word 8 CHPIORBK (83) Base IORBK region
Lock for this IORBK and CHPBK work area
0298 664 Dbl-Word 8 CHPLOCK (3) Lock to serialize this block
Commit and recovery control data.
Last items in the current block
used to update commit cursors when
successfully sent to tape.
02B0 688 Signed 2 CHPCMCLR (0) Beginning of area to be cleared
before reuse for trailer
02B0 688 Address 4 CHPCURTK Last ticket contained in current
block
02B4 692 Address 4 CHPCMSSQ Last SSQBK
02B8 696 Address 4 CHPCMCUR Address of next Vpage slot in
last SSQBK
02BC 700 Signed 4 CHPCURHD Displacement in header of cur hdr
02C0 704 Signed 4 CHPCMXAB Amt of XAB data associated with
last tkt remaining to be written
02C4 708 Address 4 CHPLSTCW CCW address of the last piece of
data for files that completed in
the current block. If = 0 then
block contains no complete files
02C8 712 Signed 4 CHPLLPTR Last offset in page list +1 used
02CC 716 Address 4 CHPLSTHD Hdr addr for last completed file
02D0 720 Signed 4 CHPLBLKZ Save last block size at last
complete file/tkt in this block.
Counters, etc.
02D4 724 Character 16 CHPTKTS Queue of files completed in this
channel program. Moved to TAPTKTQ
when I/O completes OK.
Single-threaded double-headed
FIFO queue terminated by zero
02D4 724 Address 4 CHPTKTSH Head of CHPTKTS
02D8 728 Address 4 CHPTKTST Tail of CHPTKTS
02DC 732 Signed 4 CHPTKTCT Corresponding count of files on
CHPTKTS
02E0 736 Signed 4 * Reserved
02E4 740 Signed 4 CHPENTRY Current entry in the header
02E8 744 Signed 4 CHPLIMIT After the last entry in the hdr
02EC 748 Signed 4 CHPLINDX Index into CCW list of buffers
02F0 752 Signed 4 CHPOFFST Offset into block where data
should be added
02F4 756 Signed 4 *
02F8 760 Signed 4 CHPPOOLC Count of pool pages (data pages)
02FC 764 Address 4 CHPPLIST (14) List of pages locked for this blk
00000038 CHPPLLEN *-CHPPLIST Length to clear
0000000E CHPPLMAX 14 Maximum number of entries
0334 820 Signed 4 * End flag for PLIST - zero = end
00000088 CHPCMCRL *-CHPCMCLR Length of area to be
cleared before reuse for trailer
Queue of CHPbks link field
0338 824 Address 4 CHPNEXT Next work area in circular queue
Save area across GOTO I/O request
033C 828 Signed 4 CHPSAVE (7) Save R3-R9 across call to IOS.QS
Channel Program and Header Block copied from TAPBK
0358 856 Dbl-Word 8 CHPPGM (26) Modeset + hdr + 3*8 (desc + xab +
data)
0428 1064 Dbl-Word 8 CHPHEADR (37) Block header
Pointers
0550 1360 Signed 4 CHPIDAWA IDAW list anchor
0554 1364 Signed 4 CHPIDWNX Next available IDAW slot
0558 1368 Signed 4 CHPBUFHL Host logical buffer addr anchor
055C 1372 Signed 4 * Reserved
00000004 CHPHLLEN 4 Length of CHPBUFHL entries
End of CHPBK definition
0560 1376 Dbl-Word 8 CHPRESVD (10) Round it off
00000318 CHPLENBY *-CHPLOCK Extra space (after
IORBK)
000005B0 CHPIOBY *-CHPBK Whole work area size in
bytes
000000B6 CHPIODW CHPIOBY/8 Same in double words
00000002 CHPBKCNT 2 Number of work areas per drive
Redefinition for the channel program build area
0358 856 Dbl-Word 8 CHPMSCCW Modeset, if applicable
0360 864 Address 4 CHPHDCCW Read/write header CCW
0364 868 Address 4 CHPHCCWA Address of the CHPHEADR
0368 872 Address 4 CHPCCW1 First general CCW
036C 876 Address 4 CHPCCW1A Address section for deblocking
0370 880 Dbl-Word 8 CHPCCWS (20) File write CCWs - desc, XAB, data
Or read CCW's - up to 8 pages
00000015 CHPCCWCT (*-CHPCCW1)/8 Number of CCWs
(doublewords)
000000B8 CHPPGMLN *-CHPPGM Must match size defined
above
Redefinition for the tape block header section
0428 1064 Character 4 CHPBLKID Generally 'XHDR', could be 'TRLR'
042C 1068 Signed 4 CHPBLKSZ Size of this block in bytes
0430 1072 Dbl-Word 8 CHPTIME Time stamp
Definition of an individual entry
0438 1080 Dbl-Word 8 CHPHDENT (0) Start of the first entry
0438 1080 Character 8 CHPOWNER File owner
0440 1088 Signed 4 CHPFSEQ File sequence number for drive
0444 1092 Signed 4 CHPSYSID System spool file ID when dumped
0448 1096 Signed 2 CHPSPID User spool file ID when dumped
044A 1098 Bitstring 1 CHPHDFLG Flags describing file section
044B 1099 Bitstring 1 *
044C 1100 Signed 4 CHPMAPCT Count of map pages needed for
file
0450 1104 Signed 4 CHPPAGNO Starting relative page number
0454 1108 Signed 2 CHPPAGCT Count of data pages in block
0456 1110 Signed 2 CHPXABSZ Size of XAB section in block
0458 1112 Signed 2 CHPTKOFF Offset to ticket - file
descriptor
045A 1114 Signed 2 CHPXAOFF Offset to extended attributes buf
045C 1116 Signed 2 CHPDPOFF Offset to data pages
045E 1118 Signed 2 *
| |