Cannot get screen resolution to anything other than 640x480 (x-post from Help!)

Black Mesa Archive In-game Issues (Mod)
#1

Not sure if Help! or In-Game Issues is the right area for this, so I’m posting here as well:

I just installed Black Mesa, launched via Steam & downloaded the Source SDK component. When I fire up BM, it works, but the screen is in 640x480, and the video options don’t show anything else in the dropdown (selecting 16x9 gives me 854x480, but that’s it).

I tried providing command line args to the app by right-clicking on the Steam entry and providing “-w 1280 -h 720” in the Launch Properties dialog, but this doesn’t work either - still low rez, still no choices in the dropdown.

My setup is a Intel Q6600 w/Asus P5K-E motherboard, Radeon HD 4870, and the monitor is a Panasonic 720P projector (PT-AX100U), connected with an HDMI cable.

Any ideas where I can get the Source engine to realize I have a higher-rez monitor?

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.