External displays are superbly useful in communicating information to the operator of a system. Here, I provide information specifically on non-conventional external displays (not monitors or terminals). We generally used these to communicate specific information to the operator or administrator of a system. Usually, these displays are either small character or pixel-based displays (LCD, LED, or VFD) or smaller graphical displays. While touchscreen displays would be very useful, they are also quite expensive, and out of the scope of my knowledge or plans.
While external LCD displays can do a lot including monitoring instant messaging and other online services, there are a lot of useful administrative purposes:
- network bandwidth
- monitoring system CPU usage, temperature, and other parameters
- log monitoring
- summary of problems from network monitoring software such as Nagios.
Ideally, each system in a rack could be outfitted with a small LCD and a set of LEDs (red/green or red/amber/green) controlled by software, which would alert an operator to problems without even requiring a console login.
Models and manufacturers
- The picoLCD unit from mini-box.com provides a 2x20 character display ready-to-use with a USB interface and commonly available software.
Fully pre-built units
- The Pertelian External LCD Display v4 carried by thinkgeek.com only advertises support for Windows, but provides a good example of the uses for an LCD - it can do everything from monitoring stocks, news, forums, eBay, and instant messaging to system information, network bandwidth, and playlist information.
Palm as LCD Display - using an old Palm-based device as an external LCD display.