PicturephoneS @ CMU

An initiative of the History and Science Technology group

Picturephone Mod II

The Picturephone Mod II was a technological marvel. Its 5.5 x 5 inch screen offered full-motion black and white picture with 250 lines resolution at 30 interlaced frames per second (horizontal scan rate of 8 kHz). The device also contained an innovative silicon photodiode array camera with a resolution of 0.8 megapixels; a small integrated mirror could be flipped allowing it to transmit either the user or documents laid in front of the device. The picture tube and integrated circuits were made at the Western Electric plant in Reading, PA. For transmission, the Picturephone required three twisted pairs of ordinary telephone cable, two pairs for video and one for audio and signaling. Picturephones could also "call" mainframe computers and render rudimentary graphics, with user input provided via a phone's number keypad.

CMU Libraries Collections

Special Collections at Carnegie Mellon University Libraries continues to grow distinctive and unique holdings relating to the history of science and technology. These collections incorporate scientific instruments and calculating machines, including a Thomas Arithmometer, Curta Type I Calculating Machine, two Enigma machines, and two AT&T Mod II Picturephones (serial numbers 700000339 and 71000139). One of the CMU Picturephones has been non-destructively modified to run modern video conferencing software, offering an interactive experience connecting new to old. Special Collections also holds books and manuscripts documenting the history of computing, information, cryptanalysis, and technology, from the Renaissance to the 20th century (see, for example, the Traub-McCorduck Collection). Partnering with HOST@CMU, Special Collections is committed to the study and preservation of the technological heritage of Pittsburgh and Carnegie Mellon University.

For high resolution media of the Picturephones, please contact us.


The History of Science and Technology group at CMU is a cross-campus, interdisciplinary initiative aimed at uncovering, clarifying, and celebrating CMU and Pittsburgh's unique historical contributions to scientific and technical development. In locating, preserving, and analyzing CMU’s historical records, from lab notes to source code, HOST@CMU works to ensure that the region's history remains alive and accessible into the future.

The Hunt Family

The Libraries are grateful for the continued support of Tod Hunt Jr., the Hunt family, and the Hunt Foundation, which has a special connection to this event. Hunt, a Carnegie Mellon Board of Trustees member, is the great-grandson of Alfred Hunt, who cofounded Aluminum Company of America, better known as Alcoa, with six other entrepreneurs in the parlor of his Pittsburgh home. His grandfather and grandmother – Roy and Rachel – donated the money for the construction of CMU’s Hunt Library in 1960. And his family’s nonprofit, the Hunt Foundation, provided the funds to purchase the vintage AT&T Picturephones that are now housed in Hunt Library’s special collections.