What is the maximum length that a Parallel Cable IV can be extended (using an extension cable)?
If an IEEE 1284 cable is used, then it can be extended up to 33 feet in length. However, it should not be used with an external parallel port switch (A-B box). NEVER use a Parallel Cable IV with a dongle.
Note: The majority of testing focused on using the Parallel Cable IV without an extension.
Therefore, correct functionality is not guaranteed when extensions are added. For example, if the cable does not comply with the IEEE 1284 standard, a standard parallel port might not have enough drive strength over the length of the extension.