The computer-generated drawings shown here illustrate the capacity of CADD programs—Computer-Assisted Drafting and Design—to generate drawings of extant remains, to add archaeologists’ reconstructions and to rotate these drawings to demonstrate different views.

Drawing 1 shows a plan of the gateway to the Acropolis in Athens as rebuilt early in the fifth century B.C. The gateway had been almost completely destroyed by the Persians in 480 B.C. The reconstruction shown here, generated by author Eiteljorg, assumes that the Athenians rebuilt the gateway in the Mycenaean style of its predestruction predecessor. Green on the plan indicates extant remains, while blue indicates elements that are no longer extant but virtually certain. Elements shown in black, however, have been reconstructed on the computer.

Drawing 2 is the computer’s ground-level closeup of the walls and steps actually found in the corner where the steps to the upper courtyard meet the steps to the right (see arrow on plan). The two large vertical blocks at upper left are marble; to the right is a stack of five limestone blocks, and farthest to the right is another vertical marble block topped by two smaller limestone blocks. One feature of the CADD program is the ability to display specific building materials. For instance, when considering an earlier stage of the entrance, Eiteljorg called up a view with only the marble blocks shown and realized that all the limestone material belonged to the later period.

The computer also allows the viewer to take imaginary flight over the site, as in drawing 3. Here the viewpoint is from above, looking towards the conjectured entrance. Eiteljorg has assumed that the shape of the lintel and relieving triangle above the doorway were in the Mycenaean style. The computer can also swing the viewer around, as in drawing 4, where we see the entrance from the inside looking out.

The computer’s versatility is not restricted merely to rotating drawings. Once the computer receives data on physical remains dated to different periods (whether real or hypothetical), the investigator can ask it to display selectively those remains from a particular time. In addition, the computer can show drawings of structural elements made of specified materials or specific architectural details—even single stones.