Retro · Nostalgia
IBM PC AT and Intel 286: the blue screen of the office
In August 1984 IBM announced a computer that was not for games and not for the demoscene. It was for work, and that is exactly why a whole world of programs gathered around it: two blue panels, white letters on a blue background, formulas, databases and texts without surprises. Here is what the machine was, what made it indispensable, and which parts of its old story do not stand up to checking.
"Price $4,000–6,000, 20 MB hard disk as standard"→ Model 68 is $3,995 and has no hard disk; Model 99 is $5,795 and has a 20 MB disk. [1]"Video EGA / VGA"→ IBM announced a monochrome and a colour (graphics) adapter; VGA came later. [1]"Twice as fast as the XT at the same MHz"→ IBM claims "more than twice as fast as the previous models of the family", at 6 MHz. [1]"The AT bus lives on in ATX motherboards"→ removed; the AT bus became the ISA standard, but nothing is claimed about today. [4]"WordPerfect: two brothers in Utah"→ the product originated at Brigham Young University; the company is from Utah. There are no brothers in the source. [8]"Corel WordPerfect Office X9"→ the current edition is WordPerfect Office 2021. [3]"DESQview works in protected mode with pre-emptive multitasking"→ it runs in real mode on top of DOS; a faulty program can crash the system. [13]"MS-DOS 6.x: 1992"→ MS-DOS 6.0 is from 1993."Windows 95 requires a 386SX"→ the minimum is a 386DX. [16][17]"Pravetz 16: 8088 at 8 MHz with an NEC V20, not an AT"→ the Pravetz 16 is XT-compatible with an 8088 at 4.77 MHz; a separate Pravetz-286 model exists. [18]- Removed as unverifiable: clone prices, Norton SI indexes, Lotus sales "over a million in 2 years", "AutoCAD 5× slower without a coprocessor", the names of Bulgarian manufacturers and institutions, the story with "Galin's opinion" (personal opinion belongs on galin.kagami.bg).
01 · THE MACHINEIBM PC AT: August 1984
The IBM PC AT (model 5170) was announced on 14 August 1984, with first deliveries planned for 14 September. It ran on an Intel 80286 with a clock speed of 6 MHz, had a 16-bit data path and 24-bit addressing. Among the standard features were a 1.2 MB floppy drive, a battery-backed clock, a key lock and eight expansion slots [1].
| Parameter | Model 68 | Model 99 |
|---|---|---|
| Price at announcement | $3,995 | $5,795 |
| Memory, standard | 256 KB (up to 512 KB on the motherboard) | 512 KB |
| Hard disk | none (20 MB optional) | 20 MB |
| Floppy | 1.2 MB, 5.25″, also reads and writes 360 KB floppies | |
| Coprocessor | Intel 80287, optional | |
With added modules the memory grows to 3 MB; the processor's address space is 16 MB [1][5]. IBM described the machine as "more than twice as fast" as the previous family. Creative Computing magazine wrote in December 1984:
“The folks at IBM have done it again.”
Creative Computing, December 1984, quoted via [4]
The same magazine added that for most people the power of the AT was superfluous and the price was at the top of the range [4]. The first 20-megabyte disks were known for their poor reliability [4]. The museum of the University of Amsterdam keeps a working AT and still uses it to drive plotters and terminals [2].
02 · THE PROCESSORIntel 80286: the chip that did not want to be an office chip
Intel introduced the 80286 on 1 February 1982. The chip has about 134,000 transistors and a 24-bit address bus (16 MB), and is the first x86 processor with protected mode and memory management [5]. Intel expected it to be used mainly in industrial automation and telecommunications, not in personal computers [5]. The first chips were for 5, 6 and 8 MHz, with a 12.5 MHz variant coming later; AMD and Harris released versions at 16, 20 and 25 MHz [5]. By 1987 Intel had produced five million 80286s [5].
Protected mode has a price: the processor cannot return to real mode without a restart, and most DOS programs were not written for it. So although the 286 was created for multitasking, for many years it simply ran DOS programs faster [5]. Bill Gates called the 80286 "brain-damaged" precisely because it cannot run several DOS applications at once [5].
After the 80286 came the 80386, which added "virtual 8086" mode and solved this problem. We tell its story in a separate post.
03 · NORTON COMMANDERThe blue screen that became "DOS itself"
Norton Commander was written by John Socha, who started work on it in the autumn of 1984, while still a doctoral student in applied physics at Cornell University. The first edition came out in 1986 from Peter Norton Computing; the last DOS version, 5.51, is from 1 July 1998 [6]. The idea is simple: two panels with lists of files, a command line at the bottom and the function keys with ready-made actions: F3 to view, F4 to edit, F5 to copy, F6 to move or rename, F7 for a new directory, F8 to delete, F10 to exit [6].
In Eastern Europe the blue screen of NC became a synonym for DOS. According to the program's historian Nikolai Bezroukov, many users in the region "never realised that this was not the native interface of DOS" [7]. Mouse support appeared around version 3.0, and in 1988 InfoWorld judged it "far ahead of the rest" [6].
The idea has not died. NC's descendants today are Midnight Commander, Far Manager, Total Commander, Double Commander, muCommander and Commander One [6].
04 · THE SOFTWAREThe rest of the DOS stack
The 286 machine became indispensable thanks to a handful of programs. Here is what can be verified about them.
| Program | What it is | Verified facts |
|---|---|---|
| Lotus 1-2-3 | Spreadsheet | Released on 26.01.1983; 175,000 copies sold in the first year. [11] |
| WordPerfect | Word processor | Began at Brigham Young University, the company is from Utah; for DOS since 1982; version 5.1 (1989) was the standard of the DOS market. [8] |
| dBASE | Database | dBASE II was among the first programs for the IBM PC (1981); dBASE III came out in May 1984; dBASE IV was announced in 1988 and reached the market after a delay, in early 1989. [12] |
| Turbo Pascal | Environment and compiler | Released on 20.11.1983 at $49.95; version 5.5 (2.05.1989) introduced object-oriented features. [9] |
| Turbo C | Environment and compiler for C | Version 1.0 on 13.05.1987; replaced by Turbo C++ in 1990. [10] |
| Norton Utilities | Utility programs | First edition 1982 with UNERASE; Speed Disk in 1987; Norton Disk Doctor in 1988. [15] |
| Ventura Publisher | Desktop publishing | Released in late 1986 and also runs on 286-based machines; distributed by Xerox. [14] |
| DESQview | Windows and multitasking on top of DOS | July 1985; runs in real mode, so a faulty program can crash the whole system. [13] |
WordPerfect is not a museum exhibit. Corel still sells WordPerfect Office 2021 today [3]. This trio, Lotus for the numbers, dBASE for the data and WordPerfect for the texts, is known as the "application trio" of the PC-compatibles [12].
05 · THE CLONESA machine that became the standard
The architecture of the AT is open and IBM hardly managed to protect the name "AT". Large companies that were late with PC-compatibles rushed to release AT-compatibles; by the end of 1985 they had sold about 100,000 such computers, and the IBM AT itself about 350,000 [4]. In the USA the Tandy 3000, Compaq Deskpro 286, HP Vectra, Zenith Z-286 and Epson Equity were popular; in Europe most AT clones were more or less nameless [4].
The bus of the AT became ISA. The disk interface was later standardised as ATA ("AT Attachment"), which gave rise to IDE and PATA [4]. In April 1986 IBM sped the 286 up from 6 to 8 MHz [4]. On 2 April 1987 IBM announced the PS/2, and in June 1987 the end of the AT; the last machines shipped in July [4]. There was no direct successor: users had to either give up their ISA cards or buy a clone. Only in September 1988 did the PS/2 Model 30 286 arrive [4].
The end of the era was not abrupt. MS-DOS 6.0 came out in 1993, and the last standalone version, 6.22, in 1994 [16]. Windows 95 was released on 24 August 1995, and Microsoft stated a minimum of a 386DX and 4 MB of memory [17]; for the 286 the road to Windows ended there.
06 · AT HOMEThe Pravetz and the 286: what we know
The Bulgarian Pravetz computers are two families. The 8-bit series are Apple II-compatible. The Pravetz-16 is IBM PC/XT-compatible with an Intel 8088 at 4.77 MHz (256–640 KB of memory); there are also later models: the Pravetz-16ES with an 80186, the Pravetz-286, -386 and -486 [18]. Our old claim that "the Pravetz 16 is an 8088 at 8 MHz with an NEC V20" is not confirmed by the source and has been removed.
Everything else in the old text about Bulgaria (mass deliveries of Taiwanese and Korean clones, specific institutions and traders, Bulgarian firms for Cyrillic fonts and the "standard Bulgarian stack") we could not check against a primary source, so we removed it. The story of the XT and the Pravetz is told in more detail, with checked facts, in the post about the IBM PC XT and the Pravetz.
07 · TIMELINEThe era of the 286
| When | What happens |
|---|---|
| 01.02.1982 | Intel introduces the 80286. [5] |
| 14.08.1984 | IBM announces the PC AT; first deliveries from 14.09.1984. [1] |
| 1986 | Norton Commander is released; in April IBM releases the AT at 8 MHz. Ventura Publisher follows at the end of the year. [4][6][14] |
| 1987 | Turbo C 1.0 (13 May); the PS/2 is announced and the AT is taken out of production. [4][10] |
| 1989 | WordPerfect 5.1 establishes itself; Turbo Pascal 5.5 (2 May); dBASE IV reaches the market. [8][9][12] |
| 1993 | MS-DOS 6.0. [16] |
| 24.08.1995 | Windows 95. [17] |
| 01.07.1998 | Norton Commander 5.51, the last DOS version. [6] |
One thought remains: the 286 is not a machine for games, but it is a machine that gets work done. The two-panel view, the clean text and the clear order have not aged; today we simply call them "ergonomics".
08 · SOURCESSources
- IBM, Announcement Letter 184-097, 14.08.1984 (primary source; copy) — retrocmp.de
- UvA Computer Museum, "IBM PC-AT" (museum) — ub.fnwi.uva.nl/computermuseum
- WordPerfect, the product's official website — wordperfect.com
- Wikipedia, "IBM Personal Computer/AT" (secondary; cites PC Week, Creative Computing, Computerworld, NYT) — en.wikipedia.org
- Wikipedia, "Intel 80286" (secondary; cites Intel Solutions) — en.wikipedia.org
- Wikipedia, "Norton Commander" (secondary; cites J. Socha) — en.wikipedia.org
- N. Bezroukov, "The History of Development of Norton Commander" (secondary, essay) — softpanorama.org
- Wikipedia, "WordPerfect" (secondary) — en.wikipedia.org
- Wikipedia, "Turbo Pascal" (secondary) — en.wikipedia.org
- Wikipedia, "Turbo C" (secondary) — en.wikipedia.org
- Wikipedia, "Lotus 1-2-3" (secondary) — en.wikipedia.org
- Wikipedia, "dBase" (secondary) — en.wikipedia.org
- Wikipedia, "DESQview" (secondary) — en.wikipedia.org
- Wikipedia, "Ventura Publisher" (secondary) — en.wikipedia.org
- Wikipedia, "Norton Utilities" (secondary) — en.wikipedia.org
- Wikipedia, "MS-DOS" (secondary) — en.wikipedia.org
- Wikipedia, "Windows 95" (secondary) — en.wikipedia.org
- Wikipedia, "Pravetz" (secondary) — en.wikipedia.org
Checked on 03.10.2026. Translations from English are our own. Many of the dates and numbers come from secondary sources; where possible, we have checked them against a primary source.
09 · RELATEDContinue from here
IBM PC XT and Pravetz: two universes from one era
The predecessor of the AT, and the Bulgarian Pravetz 16 and 8C, with checked facts.
Retro · BlogCommodore 64
The home computer that did for games what the AT did for the office.
Retro · BlogMacintosh
The other road: a graphical interface instead of two blue panels.