The LaST Upgrade Part 49 - STE VIDEO DAC

March 22, 2024 - Last updated March 22, 2024


The STE VIDEO DAC upgrade substitutes the Atari STE RGB resistor ladder with a contemporary digital integrated DAC IC. This enhancement delivers significantly crisper, cleaner colors without any ghosting or color bleeding, alongside improved color contrast.



This guide assumes your motherboard doesn't have the 32MHz OSC fitted U402. If you have a OSC fitted there, then the current DAC board isn't compatible with your motherboard.

Remove the row of resistors as down. I suggest cutting one end of the resistor to make them easier to remove.

NOTE: One resistor is NOT removed.


Next remove the 3 RGB driver transistors and suck up the solder in the OSC holes indicated by the 2 yellow arrows.

NOTE: If you have a OSC fitted there, then unfortunately your motherboard isn't compatible with the current DAC board.


The transistor as highlighted in the yellow circle below is unfortunately a little bit in the way. Carefully bend it forward or backwards making sure it does not short out on anything and try make it as lowdown as possible.

Technically you could remove this transistor if you never plan on using the MONO output of the RGB port. But I think it is better to try and keep it just in case.


Next place header pins in the marked locations. Solder a couple pins and make sure your PSU fits before soldering the rest.

NOTE - Version 0.1 PCB has slightly missalighed RGB pins. So they have to be fitted at a slight angle (or you could use some wire).


solder a thin wire to the top of the backboard as shown below. Route the wire through a hole somewhere ( do not solder the wire in the hole!!) and solder the other end to the bottom of the shifter pin 55.


Basically you are done now :)

The image below really does not do it justice because of my rubbish monitor & cam, image scaling etc, but the quality is far superior than the original RGB drivers.