What does the 15 pin port on the back of the iMac do?

Posted:
in Genius Bar edited January 2014
Today I changed the battery in my iMac for the first time, and when I removed the shell of the iMac, I found a 15 pin serial port... what is this for? I was under the assumption that Mac's had no serial ports?



Les.

Comments

  • Reply 1 of 7
    ringoringo Posts: 329member
    Do you mean the VGA port? Is it under a small removable cover?
  • Reply 2 of 7
    idunnoidunno Posts: 645member
    Yes. What is a VGA port?
  • Reply 3 of 7
    lucaluca Posts: 3,833member
    We need more information.



    1) How many rows of pins? 2 or 3?

    2) What model iMac? Tray loading? Slot loading? Flat panel?



    The tray loading iMacs used the old Macintosh DB-15 monitor interface instead of the industry-standard VGA. That might be it. Other than that I really have no idea.
  • Reply 4 of 7
    ringoringo Posts: 329member
    VGA is an industry-standard video port.



    If you have a slot-load iMac, it's a VGA port and can be used to hook up an external monitor. If you have a tray-load iMac, then it's already being used by the built-in monitor, so it doesn't matter anyway.



    I hope that answers your questions.
  • Reply 5 of 7
    idunnoidunno Posts: 645member
    It is three rows of five pin holes.



    My iMac is a slot loading CRT model.
  • Reply 6 of 7
    ringoringo Posts: 329member
    Yup, that's a VGA port.



    It's not very useful to most people, though. Unfortunately, iMacs aren't capable of monitor spanning, only mirroring. In other words you can plug in a second screen, but it's going to show the same thing as the internal one.
  • Reply 7 of 7
    It is, however, quite useful if your iMac's CRT goes on the blink.
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