A portable computer is contained within an outer metal case which physically encapsulates and protects the working components of the computer in the closed, portable configuration. The metal case includes a base which serves as a heat sink for transferring waste heat from heat producing electrical components to the surroundings in the open, operating configuration of the computer. The heat producing components are mounted and located in the base to maximize the transfer of heat to the base. A display housing is pivotally mounted on the base by hinge assemblies for swinging movement between a closed and latched position on the base and an upward and rearwardly inclined angle for viewing by an operator positioned in front of the computer. Stop pins coact with the hinge assemblies for holding the display housing at the desired angle of view, and torsion springs are associated with the hinge assemblies for preventing inadvertent slamming of the display housing against the base during closing. Electrical cables are guided from the base through the hinge assemblies and to the display by cable guides which protect the cables against snagging and unnecessary flexure. A single connector connects an audio circuit on a modem to use either a standard hand set for voice communications or a passive speaker and microphone as an acoustic coupler for data communications.