CPT Corporation
| Company type | Private |
|---|---|
| Industry | Computer hardware, Word processing systems |
| Founded | 1 January 1971 in Minneapolis, Minnesota, United States |
| Founder | Dean Scheff, James Wienhold, Richard Eichhorn |
| Headquarters | Minneapolis , United States |
Area served | United States |
Key people | Dean Scheff (founder) |
| Products | CPT 4200, CPT VM, CPT 8000 series, CPT 6000 series, CPT 9000 series, CPT Phoenix series, CPT PT software, CPT Genius Display, Daisy wheel printers |
CPT Corporation was established in 1971 in Minneapolis, Minnesota by Dean Scheff, alongside co-founders James Wienhold and Richard Eichhorn. The company’s initial product was the CPT 4200, a dual-cassette tape device that operated a modified IBM Selectric typewriter, designed to facilitate text editing and word processing functions.
In 1976, CPT introduced the CPT VM (Visual Memory), which featured a partial-page display screen paired with a dual-cassette-tape mechanism. This was followed by the CPT 8000, a desktop microcomputer boasting a full-page display and dual-diskette drives, capable of driving independent daisy wheel printers.
Subsequent product developments included: (1) enhancements and variations within the 8000 series; (2) the more affordable CPT 6000 series with smaller screens and reduced capacity; (3) the CPT 9000 series, compatible with software designed for the IBM personal computer; (4) the graphical-oriented CPT Phoenix series; (5) CPT PT, a software-only solution for IBM PCs and compatible clones; and (6) other related products.
The CPT name, initially selected for its phonetic appeal, later came to represent acronyms such as "cassette powered typewriting" and subsequently "computer processed text." The company’s primary rivals were IBM, Wang, Lanier, and Xerox.
Within Minnesota’s high-tech sector, CPT held the fifth position behind industry leaders like 3M, Honeywell, Control Data, and Medtronic. During the mid-1980s, annual revenues approached $200 million before declining due to widespread adoption of personal computers. By the end of the 20th century, CPT had largely discontinued its manufacturing operations.
Cassette based
The CPT 4200 featured dual cassette tape units paired with a compact keyboard that controlled a modified IBM Selectric typewriter. As users typed, keystrokes were simultaneously printed on paper and recorded onto an output cassette. This output tape could later be replayed as input to facilitate text editing.
Its keyboard incorporated function keys such as "skip," "read," and "stop," along with mode selectors including "word," "line," "paragraph," and "page." Activating "read" played back selected text from the input tape to both the typewriter and output tape, while "skip" allowed bypassing certain text without printing or recording it.
Newly typed content on the Selectric keyboard appeared immediately on paper and was recorded onto the output tape. This process enabled document editing by combining playback of stored text segments, skipping unwanted sections, and adding fresh input. The system was priced at roughly $5,000 in early 1980s currency.
An optional accessory called the CPT Communicator permitted data exchange between text-editing devices or remote computer systems via telephone lines; however, pricing details for this add-on are not documented.
CPT 8000 series
Launched in spring 1976, the CPT 8000 marked the company's entry into microcomputer production. This all-in-one desktop system included two 8-inch floppy disk drives, an adjustable keyboard, and a full-page vertical CRT display designed to mimic paper with black text on a white background for comfortable reading. Targeted at users familiar with typewriters, its keyboard featured additional keys such as IN, OUT, PRINT, and an initially named OOPS key (later renamed to avoid customer offense).
The display presented a complete page of text with fixed margin and tab stop indicators. Instead of obscure error codes, it provided clear status messages like "The printer needs a new ribbon." Its hardware supported fluid scrolling and panning at speeds unmatched for many years. The 8000 operated on its own multitasking system driven by hardware interrupts but was also compatible with CP/M, enabling users to run popular CP/M software and develop applications in languages such as Fortran, CBasic, and Cobol.
Powered by an Intel 8080 processor, this system pushed the limits of display technology performance at that time. Memory began at 64K but was often upgraded to 128K or 256K through custom bank switching circuits. The initial cost was approximately $8,000 for the base unit plus an additional $8,000 for the accompanying daisy wheel printer. The product’s model number was occasionally mistaken for its price upon release.
An optional RS-232 serial port allowed electronic document transmission; notably utilized for accessing Westlaw’s legal research database.
A version certified as tempest-compliant ensured electromagnetic shielding to prevent unauthorized interception or monitoring of electronic emissions.
CPT WordPak
The CPT WordPak line represented CPT's inaugural external document storage solution, allowing multiple 8000 series workstations to electronically share files.
Prior to WordPak, documents were saved on removable 8-inch floppy diskettes, necessitating manual transfer or duplication to share content, which often led to numerous copies.
Connectivity between the 8000/6000 workstations and WordPak was established through a proprietary circuit board and cable.
The initial WordPak model housed a single Shugart SA4000 14" hard disk offering 30 megabytes of storage; the subsequent WordPak 2 incorporated a second drive, effectively doubling the capacity to 60 megabytes.
CPT SRS 45
Serving as an early form of server, the CPT SRS 45 combined a ZIP drive with shared hard disks accessible by up to eight CPT units via the PC AT bus. Primarily engineered by Bill Davidson, it utilized network cards that seamlessly integrated with the IBM BIOS 55AA driver, enabling shared drives labeled D, E, F, and Z without requiring additional software. File sharing was managed by assigning distinct directories to prevent concurrent write access conflicts. This pioneering plug-and-play network storage system was ahead of its era but did not gain widespread recognition. Like other CPT hardware, its capabilities extended beyond word processing.
CPT PT Software
CPT PT was a simplified iteration of CPT software designed for MS-DOS running on IBM PC compatible machines. It served as a data exchange bridge with personal computer applications and provided users familiar with standalone CPT systems a dual-window word processing environment. In the early 1980s, it was priced at approximately $200.
CPT Genius Display
The Genius display was an independent, vertically oriented monochrome greyscale CRT monitor paired with an IBM PC form factor display card that enabled high-resolution full-page text and graphics on IBM PC compatibles. A dedicated MS-DOS driver supported an 80x66 character text mode, matching standard printed page dimensions. The device bore resemblance to the Phoenix monitor (without an integrated keyboard).
Popular text editors such as Quicksoft's PC-Write, WordPerfect, WordStar, and VolksWriter supported this full-page mode. Lotus Symphony and Lotus 1-2-3 provided both full-page and dual-screen modes (two landscape screens stacked vertically).
Under Windows 3.0, drivers facilitated full-page displays including monochrome graphics.
Notable specifications included:
- Character cell size: 9x15 pixels
- Character matrix: 8x12 pixels with descender support
- Progressive scan at a vertical refresh rate of 60 Hz
- Horizontal scan frequency: 64 kHz
- Video bandwidth of 100 MHz
- Screen size: 15" diagonal with paper-white phosphor
Originally created by Micro Display Systems in Hastings, Minnesota as the VHR-400, this display retailed for $1,500.
Daisy Wheel Printers
Daisy wheel printers compatible with CPT’s 8000 and 8500 series word processors were manufactured by Qume Corporation and Diablo Systems. These printers supported both fixed pitch and proportional fonts but did not offer graphics printing capabilities.
Laser Printers
Laser printers played a crucial role in producing Phoenix series documents because of their capability to handle embedded graphics.