HP A4500A - VMEbus Single Board Computer 744 Motherboard Hardware Manual page 43

Altitude Operation Standards
Maximum Altitude
Operational 3000 meters above sea level
Non-operational 4572 meters above sea level
Effects of Altitude
Altitude effects the cooling of computer systems. Less air density means less cooling. Differences in air
temperature, input to exhaust, can increase significantly at higher altitudes.
Chapter
Altitude Operation Standards
51