IBM 5150 Technical Reference page 4

Federal Communications Commission
Radio Frequency Interference Statement
Warning: The equipment described herein has been certified
to comply with the limits for a Class B computing device,
pursuant to Subpart J of Part 15 of the FCC rules. Only
peripherals (computer input/output devices, terminals
printers, etc.) certified to comply with the Class B limits may
be attachedto the computer. Operation with non-certified
peripherals is likely to result in interference to radio and TV
reception. If peripherals not offered by IBM are used with the
equipment, it is suggested to use shielded grounded cables
with in-line filters if necessary.
CAUTION
The product described herein is equipped with a grounded
plug for the user's safety. It is to be used in conjunction with
a properly grounded receptacle to avoid electrical shock.
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