CPT Corporation

Figure 1. CPT 4200 system console

Figure 2. (Circa 1977) Cassette used for non-volatile storage of characters typed via an IBM Selectric typewriter keyboard into a CPT 4200 word processing system

Figure 3. The CPT 4200 console control keys

The CPT 4200 was a dual-cassette-tape unit with a small built-in keyboard that controlled a modified IBM Selectric typewriter. Keystrokes entered on the typewriter appeared on the paper as they were recorded on the output cassette, which formed a magnetic replica of the characters printed on the page. That output cassette could later be used as an input cassette, where it would be played back to the typewriter along with new keystrokes to accomplish text editing.

The keyboard of the CPT 4200 had action keys for "skip", "read" and "stop", mode keys for "word", "line", "paragraph," and "page." Pressing "read" transferred a word, line, paragraph, or page (depending on which mode key had been selected) from the input tape to both the typewriter and the output tape. Line boundaries (aka printer margins) recorded on the input tape were ignored or retained depending on whether or not the "adjust" key had been selected. Alternatively, pressing "skip" moved past the corresponding amount of text on the input tape without sending it to the typewriter or to the output tape.

The Selectric's keyboard was active for any new typing, which would appear on the paper and transferred to the output tape. Thus a document was edited by reading back those parts of the text to be retained and skipping those parts to be discarded, with new typing added from the Selectric's keyboard. Price: approx. $5000, 1980-era values.

The CPT Communicator was an add-on to the CPT 4200 that allowed data to be transferred from one text-editing machine to another, or between a text-editing machine and a remote computer, via phone lines. Price: not available.

Figure 4. CPT 8000 series: Dual floppy diskette drives are to the right of a full-page cathode ray tube (CRT) display screen. The broad horizontal bar on the screen is an after-image of the lower editing window, which almost always contained text and which after years of editing left an impression on the screen's luminescent phosphors. A daisy-wheel printer was a separate cable-connected device, not shown.

Figure 5. CPT screen: Closeup photograph of the CPT 8000-series display screen. This screen introduced the fast white phosphor P104 in 1976, which was intended to allow rapid scrolling without blurring. That phosphor subsequently became a standard in the word processing industry and elsewhere.[5][6]

The CPT 8000 was the company's first microcomputer product, exhibited in spring of 1976. It was a self-contained desktop machine with two 8 inch floppy diskette drives, a movable keyboard, and a full-page vertically oriented CRT display with black characters on a white background, for a wysiwyg view of text on paper. It was promoted as familiar and easy to use for those experienced with typewriters.

The CPT 8000 had dual-window editing, where text was assembled in an upper window from text entered at the keyboard or from one or more files brought successively into the lower window. Words, lines, paragraphs, and pages could be slid from the lower window to the upper, as in the cassette tapes of the CPT 4200, or they could be deleted from the lower window. In addition the two screens could lock and scroll up or down together.

The machine used two processors, an 8080 microprocessor and a custom display processor. 65,536 bytes of main memory were standard and were used jointly by both processors for executable code, program data, and video memory. Price: approx. $15,000, 1980-era values.

An RS-232 serial communication option was available for the 8000 series that allowed the electronic transfer of documents.

Figure 6. CPT Phoenix series: The plastic for the gray keys was color-matched to dust collected in the office so that the keys would not easily show dirt. The color of the case was then coordinated with the keys. The "soft keys" are in the upper left and right of the keyboard. Not shown is the electronics unit, which would be placed underneath the desk.

The CPT Phoenix had a separate adjustable display, a separate curved keyboard promoted as ergonomically comfortable, and circuitry in a separate box. It included a custom bit-block-transfer (BitBlt) graphics processing unit (GPU) together with a dual-CPU multiprocessor. Eight of the keys on the keyboard were "soft keys" whose meaning changed with the operation being performed and whose current definitions were maintained at the bottom of the display screen. Price: approx. same as CPT 8000.

The CPT WordPak series was CPT's first external document storage system that enabled multiple 8000 series workstations to store documents in an electronic filing cabinet.

Prior to WordPak, all documents were stored on removable 8 inch floppy diskettes. Sharing documents involved handing off the original disk, or copying the document to a second disk and 'sneaker-net-ing' (walking it over) to the second 8000. But this resulted in two copies of the document, one at each workstation.

A circuit card with the proprietary cable connector was installed in the 8000 series workstations and connected to the WordPak by a multi-conductor cable. (This was before the Ethernet standard was developed.)

WordPak 1 consisted of a single Shugart Associates 14" diameter hard disk drive with a capacity of 5 megabytes.

WordPak 2 added a 2nd drive for a total of 10 megabytes.

WordPak was designed to support the 8000 series 'fixed font pitch' documents, which did not support imbedded graphics. It was the forerunner of the SRS product.

The CPT SRS was a "shared resource system" consisting of a 35-million-byte hard disk drive that would be shared simultaneously by up to eight CPT word processing machines. At that time photographs and videos were not commonly stored digitally and a disk drive of that size could hold a shared document of up to 10,000 pages or more.

Figure 7. CPT PT screen: The screen fit the 80-character-wide by 25-line-high screen of the IBM-PC. A blue "margin scale" divides the upper and lower editing windows. The black area at the top of the upper window is outside the bounds of the paper. File name, line and column numbers, and other codes are light blue at the far top. The typing area remains above the blue margin scale, while the white page-area slides up and down, adjusting the black area as it moves.

CPT PT was a reduced a version of the software that ran under MS-DOS as an application on IBM PC compatible computers.[7] The corporation intended it as a bridge to allow data to flow in and out of personal computer packages, as well as providing a personal-computer word processing application for those familiar with standalone CPT equipment or who preferred the CPT style of dual-window text editing. Price: approx. $200, 1980-era values.

The Genius display was a stand-alone vertically oriented (portrait) configuration monochrome grey-scale CRT monitor unit and an IBM PC form factor display card to allow high resolution full page text & graphics on IBM PC compatible computers. A special MS-DOS driver was required, but allowed a text screen to be 80 characters wide and 66 lines tall (a normal printed page parameters). The display unit looked similar to that of the Phoenix monitor (minus the keyboard) shown in Figure 6 above.

Text editors such as Quicksoft's PC-Write, WordPerfect, WordStar, VolksWriter (and more) supported the full page mode. Lotus Symphony and 1-2-3 would support full page as well as dual screen mode (2 'regular' landscape screens, one in the top half of the screen with the other below.

Windows 3.0 drivers were also developed for this product that allowed for full page screen presentations, just like their dedicated word processors, but with the addition of monochrome graphics.

Some specifications:

9x15 pixel character cell

8x12 pixel character matrix, includes 3 scan line for descenders (i.e. letters g,j,p...)

13th scan line for underscore

progressive scan, 60 Hz vertical refresh rate

64 kHz horizontal scan rate

100 MHz video bandwidth

15" diagonal, 110 degree deflection, paper white, long persistence phosphor

(from at-the-time marketing literature)

The product was originally developed by Micro Display Systems of Hastings Minnesota as the VHR-400. Price: unknown

Daisy wheel printers from Qume Corporation and Diablo Systems could be connected to the 8000 and 8500 series word processors. These printers could support both fixed pitch and proportional fonts, but could not print graphics/pictures. Price: unknown

Laser printers were required for printing the documents produced by the Phoenix series word processors as the documents produced could contain embedded graphics. Price: unknown