Digital image storage & video processing-image on a 12.000 in tv rate monitor w/16-bit alu & 512x512x16 bit image storage; automatic image focusing; automatic stigmation, contrast & brightness control; microprocessor controlled digital magnification range: 10x to 200, 000x at 12mm working distance, 10x attainable; microprocessor controlled digital accelleration voltage ranges; alphanumeric digital printout; prealigned three lens electron optical column; vacuum system; macro specimen chamber