IBM System/370 145 Manual page 117

Table 20.15.1. (continued)
2305 Model 2 Module
I
2303 Drum Storage
~----------------------~-------------
Characteristic
Time channel
busy searching when
SET SECTOR is used (ms)
Minimum .112
Maximum .167
Rotation speed (rpm)
Data transfer rate
(MB)
Data validity
checking
Error recovery
performed by the
control unit
Rotational position
sensing
Multiple requesting
(allows concurrent
I/O operations on one
module)
Record overflow
Two-Channel Switch
Device contained in
the control unit
6000
1.5
10 correction code
bytes (CCB) appended
to each are~a wri tten
1. Command retry
to retry a failing
command without an I/O
interruption
2. correction of data
errors that, occur in
the data aJ:'ea of a
record is possible by
programming' using
information in
sense bytes
Standard feature
(180 sectors per track)
Up to 8 concurrent
operations per 2305
module (upt.o 1 per
module supported by
data management)
Standard fe,ature
Optional feature
Yes, to read the
control uni1t
microprogr~n and
dia9Dostic programs
A Guide to the IBM System/310 ModeJl 145
3400
.303
Two-byte cyclic check
(CC) code appended to
each area written
Not provided
Not available
One I/O operation at a
time is supported.
Optional feature
Optional feature
No
107