Strange board from an SE/30

[stevep]

Can anyone identify what this is and what it was used for?

It was in an SE/30. The main power bundle from the supply connected opposite the red wire bundle on this board and then the red bundle went to the logic board. The small black connector was mounted in the expansion slot on the back.

The small white wire was soldered to a pin on chip UG6.

Pics are here:










Thanks for the help!

 

[MacG4]

weird never seen one of these before

 

[Mike Richardson]

It looks like it uses the SE/30's power supply to deliver power to something external. I am not sure what the small white wire played in this.

 

[wally]

If you can, please identify exactly which number IC pin (or marked up photo please) that white wire once connected on UG6, and also if that wire was a single conductor or a really skinny shielded conductor. Judging from the number of pins on that connector, it not only had DC power, but also access to video, vertical, and horizontal sweep pulse information. That UG6 chip is a video display related PAL and the wire could be bringing out the pixel clock, or other frame sync information that could be useful for external frame capture, mirrored display or scan conversion purposes.

 

[MacMan]

Looks like a TTL video port to me... Many 1980's computer monitors used TTL as the standard interface so this may well be a video-out port for the SE/30 to connect an external monitor.

 

[redrouteone]

Looks like a TTL video port to me... Many 1980's computer monitors used TTL as the standard interface so this may well be a video-out port for the SE/30 to connect an external monitor.

Yes I do believe you are correct. I have seen a similar setup described in the book "Build your Own Macintosh and Save a Bundle."

http://www.vintagemacworld.com/build_own.html

 

[stevep]

Wally - it connected to what I think is Pin 1; it is on the marked end of the chip and has a dot above the pin. It was a single wire connector.

MacMan & redrouteone - closer examination today uder better light reveals "Mac Video Adapter" under the pins of the black plug on the side of this board.

I guess that solves the mystery. Thanks guys I'll put it in my parts bin.

 

[wally]

Wally - it connected to what I think is Pin 1; it is on the marked end of the chip and has a dot above the pin. It was a single wire connector...I guess that solves the mystery...

Indeed, it all makes sense, Pin 1 is the Pixel clock, and presumably that multiaperature ferrite core thingy is of low enough permeability and loss to just take a bit off the edge of the clock for EMI radiation interference control without destroying clock function altogether... [] ]'>

 

[shred]

closer examination today uder better light reveals "Mac Video Adapter" under the pins of the black plug on the side of this board.

The board looks like an interface for a Kodak/Sayett DataShow projector pad - I installed quite a few of them in Mac SEs and SE/30s in the day.

The DataShow was basically an LCD display panel in a box with a glass window on both sides. It was placed on top of a standard overhead projector to display the Mac screen on a projector screen. They were popular as a cheap alternative to the megadollar data projectors.

A quick Google found a piccie of one:

http://www.recycledgoods.com/item/17642.aspx