Definition of Adm-3a

The ADM-3A is one of the first computer terminals manufactured by Lear-Siegler. It had a 12 inch screen displaying 12 or 24 lines of 80 characters, and one of the most rugged chassis ever to be employed in any computing equipment, being constructed with a very thick metal frame (over an inch at the thickest bits). The downside of this ruggedness (including a wire mesh covering ventilation and cooling apertures, making the computer a Faraday cage) was that it weighed in at a whopping 32 lb (approx. 14.5 kg). The streamlined look of the terminal was decades later emulated by the iMac computer-line of Apple Computer.