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Adding native VGA to the OEM twinturbo pci card


Active member
Recently got tired of using the MAC-VGA adapter on my PowerMac 9600 my voodoo 1 already added a lot of cable clutter, so purchased one of the non-OEM twin turbo cards that have the VGA output on it.
Then when I placed it next to my OEM apple card (the one that is included factory on the 9600) noticed that the cards are almost the same and all components are present except the VGA plug so decided to solder one.

After soldering the new VGA female plug on the card (removed it from a random bad pc card) plugged the card into my PowerMac and nothing black screen.
So this must be some difference in the video ROM, so swapped the ROM on my commercial TT to the OEM apple card, and BANG !, the output now works :D.

Then dumped the 3.6 commercial ROM on my EPROM programmer and burned it to a W27C512 EEPROM inserted it on my OEM card and now I have two TT native VGA outputs.
The commercial ROM 3.6.1 seems to be older than the 3.8.1 that my OEM card has but don't notice anything different for now.
The only thing I need to do is build a 3d printed bracket for the card, is a work in progress.

Attached is the TT ROM that gets the VGA output to work that is used for this.


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