tIOSECT DIOSECT describes the fields used by DftSDIO as a work area when reading and writing
actual blocks of data on CftS disks. DIOSECT is Iointed to ty a v-constant in DftSNUC, and
referenced indirectly by IDIOSECT in HUCOH. 0 IOOLD 8 DIOCSi 10 PWIIT 18 20 QQDSK1 28 CCWl 30 CCW11 38 CCW2 40 CCW3 48 RWCCi 50 SEEKADR SECTNUft 58 L1STCYL LASTHED 60 t 1*1 A*2 SENSB 18 80 SEHCCW 88 DOUBLE 90 IRSIVE C8 ERRCODE DO FREERO DICFREE D8 SAVEIDT EO CCWI _____ --1 E8 A*3 I 1*4 I 1*5 160 IBM VM/310 Data Areas and Centrol Block Logic
------------ 0 0 8 10 10 18 1C 20 24
28 30 38 40 48 50 57
5C 60 61
62 7C 80 88
Name DIOSECT DSECT IOOLD DC DIOCSi DC gbIsT IQ DS PiAIT DC 1D'0' 1D'0' DMSIOW OP--- CL8'WAIT' Field Description, Contents, Meaning I/O cld PSW (from interrupt routine) CSW (from interrupt routine) DIOSECT DC C'DSK-' Filled in to correct symbolic disk number DC DC QQDSK1 DC QQDSK2 EQO cell Chain CCii----- CCii CCi1A CCW CCW2 CCW CCli3 CCW RiCCW CCli F'O' F'O' F'O' First two bytes are always 0 QQDSK1+2 Halfword X!07!,SEEKADR,X'40',6 X'03',O,X'40',1 X'31',SEEKADR+2,X'40',5 X'08',*-8,0,1 X'00',*-*,X'20',*-* copy of 16th track disk Seek Seek or set sectcr Search TIC back to search
Read or write data
address SEEKADR DC XL7'00' Seek/search information (first 3 bytes are 0) SECTNOM DC X'OO' ILQ LASTCYL DC F'O' LASTHED DC F'O' DEVTYP DC X'OO' DIOFLAG DC X'OO' in DIOFLAG TOO BIG EQO --X'04'--- liRTKF EQU X'02' QQTRK EQO X'01' DIAGNUM EQU SENSB 24 XL24'00' OF Sector number Becomes last cylinder number used
Becomes last head number used
A*1 01=2311, 08=2314, 09=3330 A*2 RDTK/WRTK flag:
Byte count is greater than 800 Writing first chain link
Handling first chain link Number assigned by CP for tIAGNOSE I/O Sense information SENCCli DC DS CCli X'04',SENSB,X'20',24 REAt 24 BYTES SILl (Scratch area, for CVD use, etc.) !1! Order 90 XRSAVE DS 15F --Registers 0-14 saved here for RDTK/WRTK CC DC AL3(0) First 3 bytes of R15 error code CF ERRCODE DC AL1(*-*) Error code (in R15 at exit) !QllQ!!1!9 I!Q in Order DO FREERO DC F'O' ----wo. cf doublewords of free storage (if any)
D4 DIOFREE DC F'O' Address of free storage for buffer or CCis D8 EO E8 E9 EA SAVEADT DC CCliX CCW DIAGRET DC IOCOMM DC LASTREC DC F'O' Handy place for an ADT address X'23',SECTNUM,X'40',1 Set sector X'OO' A*3 CP's tIAGNOSE return code if nonzero X' 00' A*4 Set to read (06) or write (05) X'OO' A*5 Number (1-14) of the last reccrd processed Section 2. CMS tata Areas and Contrel Blocks 161
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