IBM System/370 145 Manual page 112

Field conversion of 3345 models is provided as follows:
Model 1 to a Model 2, 4, or 5
Model 2 to a Model 5
Model 4 to a Model 5
Like 3830 Storage Control Model 2, ISC provides less expensive
attachment of two 3330-series strings to a Model 145 channel than 3830
Storage Control Modell. For Model 145 configurations with more than
256K of processor storage, less floor space is required when a 3330-
series string is attached via ISC instead of via 3830'Storage Con~rol
Model 2, since the ISC unit is contained in the 3345 Storage and Control
Frame.
Table 20.10.3. Hardware features of 3330-series and 2314 disk storage.
Features are available for 3330-series strings attached via
3830 Storage Control Models 1 and 2 and via Integrated
storage Control unless otherwise indicated.
Feature
Number of drives per
string or facility
Removable interchangeable
disk packs
Removable address plugs
Record Overflow feature
File Scan feature
Multiple track operations
Two-Channel Switch
Attachment of 3830 to
four channels
Second control unit
(to permit two concurrent
data transfer operations
on a string or facility)
Rotational position sensing
Multiple requesting
Command retry by control
unit and channel
Error correction data
presented by cont.rol unit
Writable storage in
control unit loaded
from a disk cartridge
Inline diagnostic tests
initiated via the CE
panel in the string or
facility
Inline diagnostic tests
initiated via the system
console
102
3330-series
2,4,6, or 8
Yes
Yes
Standard
Not available
Standard
optional
Yes, using the
Two-Channel Switch
and Two-Channel
Switch, Additional
features
Not available
Standard
(128 sectors/track)
Standard
Standard
Yes
Yes
Standard
standar.d
2314
1,2,3,4,5,6,7, or 8
(A ninth can be
included as a spare
only. )
Yes
Yes
Standard
Standard
Standard
Optional
Yes, using TWO-
Channel Switch and
2844 Auxiliary
Storage Control
Optional (2844
Auxiliary Storage
Control)
Not available
Not available
Not implemented
No
No
Standard
Not implemented
A Guide to the IBM System/370 Model 145