Editing Media access unit (section)

===Passive networking without power===
[[File:8228 setup aid.JPG|thumb|An IBM 8228 Setup Aid opened exposing the battery]]
[[File:8226 relays.JPG|thumb|Relays found on the 8226 MAU circuit board]]
The majority of IBM-implemented (actual) passive Token Ring MAUs operated without the requirement of power; instead the passive MAU used a series of relays that adjusted themselves as data is passed through: this is also why Token Ring generally used relays to terminate disconnected or failed ports. The power-less IBM 8228 Multistation Access Unit requires a special 'Setup Aid' tool to re-align the relays after the unit has been moved which causes them to be in incorrect states: this is accomplished by a 9v battery sending a charge to snap the relays back in a proper state.<ref>{{Cite web|url=http://www.mcamafia.de/mcapage0/8228tool.htm|title = IBM 8228 Setup Aid}}</ref> The advantages of having a MAU operate without power is that they can be placed in areas without outlets, the disadvantage is that they must be primed each time the internal relays experience excessive force. The IBM 8226 MAU, while containing a power jack, primarily uses this for the LEDs: relays are still used inside the unit but do not require priming.<ref>{{cite web |url=ftp://public.dhe.ibm.com/networking/nswww/neteam/998pg/c822602.pdf |archive-url=https://web.archive.org/web/20200616170934/ftp://public.dhe.ibm.com/networking/nswww/neteam/998pg/c822602.pdf |archive-date=2020-06-16 |url-status=dead |title=FTP link |work=public.dhe.ibm.com }}</ref>