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2841 STORAGE CONTROL (Continued)
Seek Address
Cell Number
Cylinder Number
Head Number
Type
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
2311
0
0
0
0-202
0
0-9
2302 Models 3 and 4
0
0
0
0-249
0
0-45
2303
0
0
0
0-79
0
0-9
2321
0
0-9
0-19
0-9
0-4
0-19
Subcell
Strip
Bar Head No.
2314
0
0
0
0-202
0
0-19
File Protection
The significance of the file mask bits is:
BO
Bl
0
Inhibit Write
Homi~
Address and Write RO
Inhibit
!!!
write
commands
Inhibit Write Home Address - Inhibit Write RO - Inhibit Write
Count, Key, and Data
Permit all write commands
B3
B4
0
0
Permit all seek and restore commands
Permit Seek CCHH and HH CCWs
Permit Seek HH CCW
Inhibit
~
seek commands
B2
B5
B6
B7
0
0
Attention
Not Used
Status Modifier
Used
with
Search and Control Unit Busy.
Control Unit End
The control unit has finished an operation.
Busy
Indicates addressed access mechanism is moving;
or used in conjunction
with
Status Modifier to
indicate Control Unit Busy.
Channel End
The control unit has received all the data from the
channel needed to do the operation called for and
the channel is freed.
Device End
Unit Check
Unit Exception
IBM
CONFIDENTIAL
Indicates that an access mechanism is free to be
used.
Indicates that a control unit or programming
error or device hardware check has been detected.
End-of-File.
S/360
93
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