IOSECT IOSECT describes the fields used by DftSITI for save registers, I/O cld PSi, and other
data when handling I/O interrupts. IOSECT is pointed to by the AIOSECT field in NUCON. o lOS AVE 40 IONTABL AUSRITBL 48 AUSRILS7 50 OLDEST 60 NEXTO 70 IOPSi 78 IOCSi 80 HOLD VSTRANGE 1///1////////// 88 //////////////////////////////1/////////1///1//////////1 , Hexadeci.al Pield Displace.ent Na.e Pield Description, Contents, !eaning o
40
44
48
4C
50
60
70
78
80
84
86
88 IOSIVE DS IONTIBL DC AUSRITBL DC AUSRILST OLDEST NEXTO IOPSi IOCSi HOLD VSTRANGE DC
DC DS DS DS DS DC
DC
DC
DC 16P P'O' A (0) P'28' A (0) 4P 4P 2P 2P P'O' H'O'
1H' O· 2P'0' Register save area
Size of user interrupt table in doublewords
Address of user interrupt table
Length of each entry
Address of last entry in table Oldest I/O old PSi and CSi Next oldest I/O old PSi and CSi Newest I/O old PSi Newest CSli Holds entry pointer for device Unknown device address saved here
Reserved for IB! use
Reserved for IB! use
196 IBM VM/370 Data Areas and Control Block Logic

KEYSECT KEYSECT defines the key table used in os simulation of BDAM files for I/O by key. KFYSECT is built dynamically from CMS free storage. 0 KEYLNGTH rATAINE 8 KEYOP 10 KEYNAME 18 KEYTYPE 20 KEYMODE KEYTBLNO KEY'IBLAD 28 TBLLNGTH A*l 1*2 KEYCOUT 30 KEYTIELE Hexadecimal Field
Displacement Name Field Description, Contents, Meaning ------------ -------------------------------------- 0 KEYLNGTH DS 1F Key length
4 DATAEND DS 1F Pointer to last data item in file
8 KEYOP DS 2F Start of PLIST for keys file
10 KEYNAME DS 2F Filename of keys file
18 KEYTYPE DS 2F Filetype of keys file 20 KEYMODE DS lH File!!!ode of keys file
22 KEYTBLNO DS 1H Item number of key table
24 KEYTBLAD DS IF Address of key table
28 TBLLNGTH DS 1F Eyte size of key table 2C KEYFORM DS 1X 1*1 Format of keys file
2D KEYCHNG DS 1X A*2 Indicates change in key table 2E KEYCOUT DS 1H Blocking factor of key table
30 DS 1F Number of bytes read
34 KEYTABLE DS OF Start of keys table (item number) Section 2. CMS rata Areas and Contrel Blocks 197