IBM 3741 Data Station Reference Manual page 122

Chapter 12. Proof Keyboard Feature
The 3741 proof keyboard differs from a standard 3741 key-
board only by a rearrangement of the numeric keys. The
proof keyboard numeric key arrangement allows the oper-
ator who is more familiar with the adding machine numeric
key arrangement to more effectively enter data.
Numeric key arrangement on standard keyboard
Figure 68 shows the numeric keys on a proof keyboard and
the numeric keys on a standard keyboard. In alpha shift,
both the standard keyboard and the proof keyboard oper-
ate the same.
Note:
A 3741 can have either the proof keyboard numeric
key arrangement or the standard keyboard numeric key
arrangement, but both numeric key arrangements are not
available on the same 3741.
Numeric key arrangement on proof keyboard
Figure 68. Proof Keyboard and Standard Keyboard Numeric Key Arrangements
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