A storage tube, Tektronix 4010, was added to NOVA 840 system at Korea Advanced Institute of Science in 1974 and efforts were made to develop an interactive graphics system. These include a software library, called TCS(Terminal Control System) [4], algorithms for hidden line and surface eliminations [5. 6], and two single user graphics systems based on different concepts involving graphic languages [2, 11]. A storage tube is a low-cost terminal, which is useful in certain applications, but introduces some problems since partial modification of the screen is not possible without erasing it entirely. Thus it has far reaching effects on the design of an interactive graphics system. The components of an interactive graphics system will be explained in section 2 and their relation ships with the choice of storage tube as the output device will be pointed out.