IBM 3270 Manual page 249

in steps 3 and 4. This line tells you the Extended Function Store
features that your 327 4 Model lA, 1 C, or lD requires.
For Model 51C, see Figure I-8. Begin at the top and work down.· Stop
at the first line that satisfies the control storage requirements you
determined in steps 3 and 4. This line tells you the Extended Function
Store features that your 3274 Model 51C requires.
Models 21A, 21C, 21D, 31A, 31C, and 31D
1-2
After having s~lected the Configuration Support option and the desired
special features, you will have to determine the control storage required.
Some combinations of functions and features will exceed the basic
control-storage capacity of the Model 21 control unit you have chosen. If
the sum of the control storage requirements exceeds 65,M6, a Model 21
control unit cannot be used and a Model 31 control unit is required. Note
the special considerations for Models 31A and 31C/SNA in step 5 below.
Do the following procedural steps to determine the control storage
requirements for the functions and features you have selected:
1. Determine which Configuration Support option contains the functions
you want.
2. Refer to the appropriate figure of control storage requirements, and
select the features and functions you want.
a. Use Figure I-9 for a 3274 Model 21A.
b. Use Figure I-10 for a 3274 Model 21C using SNA protocol.
c. Use Figure I-11 for a 3274 Model 21C using BSC protocol.
d. Use Figure I-12 for a 3274 Model 21D.
3. Determine the total storage requirements for the fe;:itures and functions
you selected in step 2.
4. If the total storage requirements calculated in step. 3 are equal to or less
than 65,536, the Model 21 can be used. If the storage requirements
exceed 65,536, however, the Model 21 Control Unit cannot be used and a
Model 31 Control Unit is required. If you determine that a. Model 31A
or a Model 31C/SNA is required, do step 5.
5 .. If you chose Configuration Support C (#9112) and either Model 31A or
31C/SNA, you must ensure that the combination of functions and
features you select forms a valid configuration by doing the following:
a. Refer to the appropriate figure of control storage requirements, and
select the 'features and functions you want.
1) Use Figure I-13 for a 3274 Model 31A.
2) Use Figure I-14 for a 3274 Model 31C/SNA.
b. Determine the total storage requirements for the features and
functions you selected in step a.
c. If the total storage requirements calculated in step b. exceed 71,680,
you must forfeit one or more features so that the total storage
requirements do not exceed 71,680.
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