Graphics Compatibility System (GCS). Primer on Computer Graphics Programming. Programmers Reference Manual
A 1978 technical manual, the Graphics Compatibility System primer on computer graphics programming, written for programmers and issued by the Defense Technical Information Center, with its wider Army engineering context in Vicksburg, Mississippi. The four pictures are plain line diagrams: scattered triangles, a wireframe box on x, y and z axes, a pair of angled strokes, and dotted squares and triangles arranged in a diagonal pattern, which a designer might borrow as minimal geometric motifs or as a study of simple vector drawing.
