Homemade PC to Mac video adapter

[amigadave]

I am in the process of completing a project I stated working on a year ago and left undone for most of the last 12 months.  It is to put my Efika motherboard and video card inside an iMac G3 case and use the original iMac crt monitor.

The iMac uses a two row 15pin video cable from the crt to a daughter board of the iMac and I have found the link below that shows the pinouts of that connector.

http://pinouts.ru/VideoCables/vga2macintosh_pinout.shtml

What is confusing to me is the webpage shows the Mac connector as "Female" at the monitor cable and "Male" 15pin High Density at the computer.

The cable from the iMac crt monitor to the iMac daughter board has a Male connector and all PC video cards have Female 15pin HD connectors, not Male as shown on the webpage above.

I don't want to make a mistake in soldering my 15pin Mac to 15pin HD PC video adapter cable, so I am asking anyone from here to verify that the pinouts shown on that webpage are correct and it is just a mistake on the gender of the connectors that is shown.  Or, do I need to mirror image the pinouts to make them correct for one side of this adapter, or both?

I don't want to burn out my Efika's video card, or the iMac crt monitor when I plug it in and turn it on.

Any experts out there that can answer these questions?  I don't have much time to complete this project before I take it to the AmiWest 2011 Show in a week and a half.

[amigadave]

I think I have found enough info to complete this adapter by looking at the pinouts for a standard VGA connector and the Mac style two row 15pin video connector (a different page).

I have my 15pin HD connector un-soldered and the wires cleaned and stripped so I can solder them to the correct pins tomorrow.  It is delicate work for these ten thumbs and weak eyes, but I think I can get it done.

The next big hurdle is figuring out how to get the iMac crt monitor to turn on without the iMac's G3 logic board installed in the computer.  If I have to direct wire the PSU and crt's power leads, I will, and then just put an inline power switch in the middle of the power cord if I can't figure out a more elegant solution.  The iMac PSU is rated for about 80 watts, so that is more than enough for an Efika w/9250 video card.

Making a custom power adapter to plug into the Efika's power connector from the iMac's PSU wiring should not be too difficult.  I just need to measure the voltages of the wires and put them into a standard power plug which will replace the Pico PSU inside the Efika now.

[Daedalus]

Well, when dealing with pinouts like that it's always good to deal with the numbers first, because pin 1 of the male will always connect to pin 1 of the female, regardless of which end has the male or female. It sounds like the same connector my old Powermac had - I don't remember any particular issues making an adaptor based on the info at the HwB

[amigadave]

Well, when dealing with pinouts like that it's always good to deal with the numbers first, because pin 1 of the male will always connect to pin 1 of the female, regardless of which end has the male or female. It sounds like the same connector my old Powermac had - I don't remember any particular issues making an adaptor based on the info at the HwB

Thanks for the link.  I am doing the opposite of that link by trying to use the iMac crt monitor with my Efika's Radeon 9250 video card.  I think I should have it soldered today and can test it tonight.