Irving Becker

Simple things should be simple, complex things should be possible.
Alan Kay

The Computer Trainer Model 650 (named also CT-650), was developed at the beginning of 1967 by a man named Irving Becker (1917-2005), whose company produced a number of radios. CT-650 is considered to be one of the earliest digital personal computers, although it was not a personal computer, as we understand the term today, but rather a manually operated simulator. Some sources list this computer as the Arkay CT-650 because, like many who were involved with early computers, Irving Becker started off in radio and from 1945 was an owner of a company, that specialized in manufacturing of radio and hi-fi kits—Arkay (after Radio Kits) International Co., located in Hicksville, NY. By the time this computer was offered, however, Becker has already changed (in 1965) the name of the company from Arkay International Co. to Comspace Corporation of Farmingdale, N.Y. (Irving Becker was the president; his wife Helen Becker, was a secretary‐treasurer of the company, and their son Nelson was an employee, a genuine family business). 🙂


By the 1960’s Irving Becker was developing many educational products, including the digital computer CT-650 and a cardboard kit for Bell Laboratories, called CARDIAC (a reference to its cardboard construction and the names of other kits like the popular Simon, Brainiac, and Geniac of Edmund Berkeley). In fact, the CT-650 was designed by the chief engineer of Comspace—Frederick E. Barrett (1935-1983), who practically single-handedly engineered Comspace’s products.

Irving Becker was dedicated to education and even made a special version of the CT-650 that was made for blind students. Aside from Braille lettering, the bulbs under each light were extra strong so as to generate more heat, that way the student could “read” the results by feeling which lights were lit.

The CT-650 is sometimes called the paperclip computer, which is a reference to a very interesting 1967 book from Edward Alcosser, James P. Phillips, and Allen M. Wolk (see the nearby image), entitled How To Build A Working Digital Computer (see the book). The book describes how to make a simple digital computer out of things one might find around the house, such as tin cans (for drum memory), screws, paper clips (for switches), and even wooden spools of thread. The design of the CT-650 seems to have relied on the book’s plans and, therefore, it is called the paperclip computer. As a matter of fact, the authors of the book sued Becker and Comspace on that basis, but unsuccessfully, because the judge ruled that as the CT-650 was not a kit and not made of paperclips, etc. it did not infringe. Moreover, the book was published in June 1967, and Comspace was granted a copyright for a “General Operating Manual for Arkay CT-650 computer trainer” on 22 June 1967, so hardly Becker had enough time to read the book and then put together an operating manual.

Computer Trainer Model 650 (CT-650) of Irving Becker
Computer Trainer Model 650 (CT-650) of Irving Becker

The CT-650 computer (see the nearby image) is quite big—54″ in length by 22″ in depth. Due to its educational destination, it has six clearly labeled sections:
• Input Unit—accepts numerical inputs in decimal form and converts these to binary or binary-coded decimal (BSD) form
• Arithmetic Unit—performs binary arithmetic and processing functions as directed by the computer program
• Control Unit—interprets the programmed instructions and directs the sequence of operations for all computer units
• Output Unit—converts problem solutions from binary or BCD form to decimal form and displays them
• Core Memory—simulates a core memory, used in storing data while solving a problem
• Program Drum—performs as magnetic drum memory and is used to store the program. It was an aluminum cylinder with spring steel contactors that could read holes in a mylar sheet that represented various instructions in a program.

The CT-650 is easily programmed and has a versatile instruction set. The users may write their own programs, or order existing or new programs from a library, called the Arkay Program Library. A small number of CT-650 devices were sold (less than 100 were made), and the price was about $1000.