LCD and Viewfinder
Canon 1Ds has a Fixed Type 2" LCD screen with a resolution of 120k dots. At only 2", the screen is on the smaller side and 120kdot resolution is lower than most of the recent models in this class.
1Ds has a built-in Optical (pentaprism) viewfinder. The viewfinder has a coverage of 100% and a magnification ratio of 0.7x. 100% coverage ensures that what you see in the viewfinder while shooting matches exactly what you will get later in your image, helping accurate framing your shots and minimizes the need for cropping images later.
Max Shutter speed
Canon 1Ds can shoot continuously at max speed of 3 fps
and has max shutter speed of 1/8000 sec
Unfortunately 1Ds doesn't have a built-in flash but it has a flash shoe for mounting external flashes.
Canon 1Ds features a Phase Detection autofocusing system. The AF system has 45 points to choose from.
Unfortunately Canon 1Ds doesn't have Video recording ability.
Connectivity and Storage
Canon 1Ds Features Compared to Main Competitors
You can download Canon 1Ds's User Manual here