Type 3A Dual Speed (16/4Mbps) Communication Adapter
Storage
This adapter provides the
ability
to operate on an IBM Token-Ring Network at
either
16Mbps
or
4Mbps. If the 16/4Mbps Token-Ring Network Gateway feature is
ordered, this adapter comes with the gateway feature.
It can also be
ordered
separately.
This adapter is a base feature on models
13R
and 63R. It is optional on these
models: 1L, 11L,
1R,
11R, 2R, 12R,
3R,
51R, 61R, 52R,
62R,
and 53R.
Large-cluster models 11L,
11R, 12R,
and
13R
of the 3174
controller
have 2MB of
base storage.
(One MB equals 1 048
576
bytes.) Models 1
L,
1
R,
2R, and
3R
have
1 MB of base storage. Medium-cluster models
51
Rand
53R
have 1 MB; models
61
R,
62R, and 63R have 2MB of base storage. Model
52R
has 512KB of base storage.
Of the
sma"-cluster
controllers,
models
81
Rand
82R have 1 MB base storage, and
the
91
Rand
92R have 2MB.
Each
controller
model has one diskette drive. The following models have a 2.4MB
diskette drive:
11
L,
11
R,
12R, 13R,
61
R,
62R, 63R,
91
R,
and
92R.
Other
models
have a 1.2MB diskette drive. Each diskette
drive
supports
5-1/4-inch, high-capacity diskettes. Large- and
medium-cluster
controllers
can
have a second diskette
drive
or
a 20MB Fixed Disk.
These storage features are designed to support
a"
basic functions. For
information
about additional features and storage needs, refer to the next section.
3174 Storage Expansion
Some functions and features that
controller
models support may
require
additional
storage. For example,
• Token-Ring Network Gateway feature
• Central site change management
utility
• Downstream load (DSL)
• Asynchronous Emulation
Adapter
•
Multiple
Logical
Terminals
•
Single
Link
Multi-Host Support
a"
requi re
some
form of additional storage.
Controllers
provide
for
storage expansion in different ways, depending upon the
model type. Large-cluster models 1
L,
11
L,
1
R,
11
R,
2R,
12R, 3R, and 13R have
two
card slots reserved
for
storage expansion;
medium-cluster
models
51
R,
52R, and
53R
have one card slot reserved.
Medium-cluster
models.
61
R,
62R, and 63R have
one module
slot
reserved
for
storage expansion.
Small-cluster
controllers
do not
support
this feature.
The 3174 Storage Expansion Feature card
is
available
in
either
1 MB
size
or
2MB
size. The cards, in combination with 3174 base storage, can provide
different
maximum
storage amounts
for
controllers
supported by different configuration
types.
2-10
IBM
3270
Information
Display.
System
3174
Establishment
Controller
Introduction