To get both players on screen, you cannot launch the game through Steam normally.
A legitimate copy of Call of Duty: Black Ops 1 installed on Steam. black ops 1 zombies split screen pc install
Two XInput-compatible controllers (Xbox 360, Xbox One, or PS4/PS5 controllers with DS4Windows). To get both players on screen, you cannot
Download the (often included in split-screen mod packs). To get both players on screen
This is usually a resolution mismatch. Double-check your Resolution Fix settings to match your desktop.