Two console, alarms and fans modules are located above and below the CPUset and I/O buses, and one is associated with each side (e.g. side A and side B). Each has standard system I/O connectors, indicator LEDs, and power switches. And each houses system-cooling fans. Console, alarms and fan modules have three software-programmable alarms, each with light and relay-controlled output. These can be connected to the standard central-office alarm interfaces for indicating "critical, major and minor" alarm conditions.