Abstract: A tomographic system wherein a movable overhead support containing a tiltable X-ray source is non-mechanically coupled to an X-ray receptor beneath an examination table for effecting a desired type of tomographic sweep or scan under the direct control of a stored program microcomputer. Depending upon the parameters inputted to the computer by the operator, the computer enables self-centering control circuits for the source and receptor whereby they are independently brought into vertical alignment over the examination table and thereafter caused to move in opposite directions under precise control of synchronized and mathematically related pulse trains applied to respective stepper motors, first to a calculated reference position and then in predetermined mutual relationship to obtain a tomogram.