IBM 3270 Information Display System: Color and Programmed Symbols (1979)

The paper

A September 1979 IBM technical pamphlet — now archived on Bitsavers — documents how the 3270 family (models 3278, 3279 and 3287) added color and “programmed symbols” to the information display system. It’s a sober, engineering-first manual: diagrams, attribute tables, control codes. But read between the lines and you can almost feel the thrill of moving past monochrome green-screens into something a little more expressive.

What it describes

The brochure lays out how color attributes and programmable character sets were implemented, how host software could select display attributes, and how terminals could be driven to show nonstandard symbols by redefining character glyphs. It has been reported that the additions enabled rudimentary graphics and emphasized fields — not full GUIs, but a big step for block-oriented mainframe terminals. For mainframe programmers in 1979, this was like getting a new set of crayons.

Why it matters

Why care about a dusty IBM pamphlet? Because this is a snapshot of user-interface evolution. Before windowed desktops, vendors squeezed more expression out of text terminals: colors, blink, intensify, and reprogrammable symbols were the tricks of the day. The document reminds us that many modern UI ideas — emphasis, iconography, even bespoke fonts — have long precedents in systems designed for totally different constraints.

Read it yourself

The full PDF is preserved on Bitsavers and was linked on Hacker News; it has been reported that the file is titled GA33-3056-0. Curious minds and historians of computing will find the nitty-gritty technical tables and examples well worth a look. Who doesn’t love a primary source that explains how computers learned to be a little more human?

Sources: bitsavers.org, Hacker News