June 1998: I received an interesting email from Mark Sutherland the other day. He swore he’d seen a picture of the iMac with a VGA port.

I quickly grabbed Macworld and looked closely at the pictures (no longer online). No sign of a monitor port. Just audio, USB, ethernet, and modem ports. I asked Mark for proof.

He pointed me to iMac2Day. Right there, on the page of photos that Jeff Keller took at the E3 show in Atlanta, is “a closeup of the ports on the right side of the iMac. You can see sound input/output, USB, Ethernet, modem, and VGA video out.”

Looking carefully, I can be sure that it’s not a VGA port, but there’s something below the other ports – in a location where there’s nothing in the Macworld photo. My guess is that it’s a video card with a Macintosh 15-pin connector.*

This is intriguing!

It appears there could be an expansion slot hidden behind the faceplate surrounding the ports. Perhaps on the iMac that Jeff saw in Atlanta, this slot had been filled with a video card, allowing it to be attached to an external monitor or projection panel.

A single expansion slot (PCI, please) would make the iMac a completely different creature for current Mac users. We could drop in a video card and continue to use our 16-21″ monitor. Or we could buy a SCSI card and use all our current SCSI hardware. Or we could put in a FireWire card, preparing the iMac for the 21st century.

Or it could be that this is simply a prototype with something extra that won’t appear in the production iMac. Steve Jobs did state that the feature set was not final.

I’d certainly find the iMac more compelling if there were a PCI slot.

* Since first writing this, I’ve received several dozen emails, many noting that only a handful of prototype iMacs exist – and some have a hand wired DA-15 video port for use with a projection panel.

Update: Given the informal name mezzanine slot, this interface existed on both the original iMac and the Revision B iMac, after which it disappeared. It use was never documented or supported by Apple, but several companies did made accessories for the iMac’s secret expansion slot. We’re working on a page to document those cards.

keywords: #imac #imacvideoout #imacexpansionslot #mezannineslot