The IBM 6580 Displaywriter System is a 16-bit microcomputer that was marketed and sold by IBM's Office Products Division from June 17, 1980 until July 2, 1986, primarily as a word processor. The system was configured with an Intel 8086 clocked at 5 MHz, 128 KB to 448 KB of RAM, a monochrome CRT monitor, a detached keyboard, a detached 8" floppy disk drive enclosure with one or two drives, and a detached daisy wheel printer, or Selectric typewriter printer.
Optional add-on cards and software give the Displaywriter the ability to connect to a modem, read Selectric Mag-Cards, create a resource-sharing LAN with other Displaywriters or IBM PCs to share printing and fixed disk storage capabilities, or emulate a 3270 or 3101 terminal. The Displaywriter primarily competed with other contemporaneous word processors, but demand from IBM’s customer base led several third-party OEMs to port general-purpose operating systems and software to the Displaywriter. IBM intended the Displaywriter to run its own internally developed special-purpose operating system titled "Textpack", but UCSD p-System, CP/M-86, and MS-DOS were also offered by Softech Microsystems (through a licensing agreement with IBM), Digital Research, and CompuSystems, respectively.
Development, Market Positioning & Design Theory The direct predecessor of the Displaywriter, the Office System/6, did not sell well. Though the OS/6 was brought to market in 1977, it was quickly out-competed by cheaper, smaller, and more capable dedicated word processors. The screen of the Office System/6 was small compared to other word processors of the time at only 6 lines of user text, and the features, while promising sounding on paper, were limited. Indirectly, between 1975 and 1979, IBM’s percentage of new market share in the word processing market fell from 83% of new machines sold to 53% of new machines sold. In 1978 and 1979 IBM's Office Products Division (OPD) began developing a replacement product line that would correct the issues of the OS/6 and help regain market share. The resulting system that ended up becoming the Displaywriter was built around the ideas of presenting the customer with feature and pricing flexibility and keeping costs low compared to previous OPD systems.
Hardware and software was broken up into modular tiers and features that an OPD sales rep would select for a customer based on their needs. Physical features and functions of the Displaywriter were broken up into discrete cards which connected to passive backplanes housed inside the electronics unit and disk unit. In addition to customer customization, this was also done to increase the turnaround speed of upgrades and repairs for IBM’s field service personnel and reduce engineering overhead when designing new feature cards. The Displaywriter electronics unit was designed around being assembled by industrial robotic systems and the assembly plant that made the Displaywriter electronics units in Austin was fully automated, one of IBMs first plants to be so as the pilot program for what ended up becoming IBM’s Automated Logistics and Production System (ALPS) that assembled the PC line and some dashboard components for the Ford Ranger.
IBM’s marketing literature positioned the Displaywriter as being uniquely useful for those who wrote legal, accounting, engineering, and educational documents with advertisements emphasizing the size of the electronic dictionary, “keying finished documents at rough draft speeds”, forms that could be created and filled with accounting data, and the graphs and charts that could be created and merged into existing documents. By 1982 the Displaywriter came bundled with a large amount of user-friendly documentation (usually 15 binders) which was aimed at helping first time users understand the functions of the menu-driven software, Textpack, which is a special-purpose operating system that was intended to be the primary means of interacting with the Displaywriter. In 1982 IBM and Softech Microsystems entered into an agreement to port UCSD p-System to the Displaywriter, at which point IBM licensed and ported a few existing pieces of p-System software for the Displaywriter and began advertising the Displaywriter as being data-processing capable.
Software & Operating Systems
Textpack
Textpack is a proprietary word processing suite developed by IBM specifically for the Displaywriter that was meant to facilitate and expedite document creation, pagination and finalization. Though Textpack bootstraps the system and is capable of limited multi-tasking, it is not a general purpose operating system like DOS or CP/M. Instead, it IPLs directly to a menu of text editing and pagination functions, with additional options to manage Textpack data disks or load one of several IBM supplemental programs, called "Feature Programs". Textpack was offered in six versions, titled: "E", "1", "2", "3", "4", & "6". These versions of Textpack were tiered in functionality, with only basic text editing being offered with the lowest Textpack versions, E and 1. More advanced features, such as customizing keyboard macros and menu shortcuts, automatically generating custom headers and footers, automatically processing math equations, or emulating a 3101 or 3270 terminal, were reserved for Textpack 4 or Textpack 6. If the Displaywriter system possesses enough RAM, and is running Textpack 4 or 6, it can also load a Feature Program concurrently with a document, and tab between editing the document and the Feature Program in real time.
Diskettes used within Textpack are always formatted as either 284 kB capacity if the disk is 1D, or 985 kB capacity if the disk is 2D, regardless of a disk's actual advertised capacity. This is a software limitation of Textpack, and not a hardware limitation of the Displaywriter floppy disk controller. Because there is no user accessible setting to designate disk sector size within Textpack, the operating system arbitrarily assumes that all 1D disks are rated as SS SD (single-sided, single-density) with 256B sectors and that all 2D disks are rated as DS DD (double-sided, double-density) with 256B sectors, which results in the aforementioned capacities. Textpacks 4 and 6 also offered the ability to combine all program disks into a single DS DD floppy, which could then also be used for document storage if space remained on the disk. The format that Textpack diskettes utilized, though similar to the IBM 3740 Data Entry System, and the Office System/6 was not interchangeable. 3740 and OS/6 disks cannot be read by a Displaywriter and vice versa. Records can instead be exchanged via communication features. Text created in Textpack is encoded with 8-bit EBCDIC. The Displaywriter also supports ASCII, but 8-bit EBCDIC is used in this context in order to take advantage of the 256 characters available per EBCDIC font set, compared to the maximum of 128 characters available per ASCII font set. The Displaywriter uses two of these EBCDIC 256 character font sets, which are stored in ROM on the display adapter card in order to achieve a total of 512 possible available characters. When instructed, the Displaywriter draws from these font sets to generate a working character table in RAM for the operating system to use. Only 256 of the available 512 characters can be used concurrently by the user, but characters from either character set can be mixed and matched to total up to 256 and characters can be hot swapped to in software. This can be done by using the "keyboard change" button on the keyboard. The ASCII code set is accessible within Textpack while using the Asynchronous or Bisynchronous communication features, where the Displaywriter converts characters stored as EBCDIC on the disk into ASCII before transmitting and vice versa after receiving ta transmission. Additionally, if the user wishes to type in ASCII directly during a communication session, they can change the keyboard to keyboard #103 which is the standard ASCII keyboard. While in ASCII mode the Displaywriter can generate all printable ASCII characters. ASCII control characters can be accessed at any time, even in EBCDIC mode, by depressing the control key (the blank key above on the keyboard), and then pressing a corresponding key in the alphanumeric block. Because they are command characters, they do not have associated visuals and don't add to the 256 displayable character total. IBM used the six character disk labels of the program disks to determine whether one disk was compatible with another. If a disk label of a noncompatible program diskette is changed to a label associated with a compatible diskette, the Displaywriter will attempt to execute the disk as if it contained the correct software, but certain features will either not function properly, or Textpack will present a halt code.
UCSD p-System UCSD p-System was the official "data processing" operating system for the Displaywriter, offered by IBM through contract with Softech Microsystems. Announced in September 1982 and made available in December 1982, as part of the contract, p-System was extensively supported by Softech Microsystems, and had multiple feature upgrades offered from IBM as time went on.
When purchasing UCSD p-System for Displaywriter, the purchaser could choose between p-System Runtime, or p-System "Development System", which was the same as Runtime, but was bundled with a BASIC compiler or an additional Fortran-77, 8086 Assembly code, or PASCAL compiler.
IBM and Softech Microsystems also sold a software upgrade that would provide p-System with the appropriate I/O calls for the RS-232 port(s) on the Displaywriter's communications card, as well as a conversion utility, titled "B&H Exchange Utility", to convert UCSD format files to "B&H" format files, which is the file structure used on the System/23 Datamaster, System/36 and System/38. p-System did not ship many units for the Displaywriter, but was notably used by the USDA Rural Development as the operating system for the "Farmer Program Servicing Action System", which was a custom software suite written by the Rural Development agency.
Additional programs offered by IBM for Displaywriter p-System included: "Financial Planning and Report Generating System", which was an advanced version of Reportpack that included financial modeling and easier report generation, "QUICKSTART Utility", which decreased load time of large programs, and "Money-Track" financial tracking by Pacific Data Systems.
CP/M-86