Intel 80286 (1982)

 
Launched February 1982

By 1982, Intel was on a roll. Their 8086 processor series (launched in 1978) was gaining widespread acceptance and in particular had found itself in the IBM PC launched the previous summer.

Four years is a very long time in the microprocessor market, and by 1982 things had moved on. While the 8086 was good enough for a single-user business computer, more sophisticated systems needed a more sophisticated CPU. Intel wanted to capitalise on the success of the 8086, but come up with a processor that could be use in more powerful multiuser systems while maintaining a good deal of compatibility with the older CPU.

The resulting Intel 80286 processor was launched in February 1982, and it became commonly referred to as the “Intel 286” quite quickly. A 16-bit CPU clocked at 5 to 8 MHz at launch, the 286 could either run in “real mode” which was directly compatible with the 8086, or a “protected mode” which was more suitable for multitasking operating systems. Up to 16MB of RAM could be addressed, although few systems would come equipped with that much memory due to the price.

Intel 80286

Although you could multitask with the 286, you could not run virtual “real mode” sessions. So it was impossible (for example) to run multiple DOS sessions on the computer. Switching between modes required either a reboot or some clever hardware and firmware trickery.

Some operating systems did use the full power of the 80286, including Microsoft’s long-forgotten version of UNIX called XENIX and a couple of other Unix-like OSes. These were niche markets, instead probably the best-known use of the 80286 was 1984’s IBM PC/AT which was a redesign of the original PC with the 286 dropped in, along with a new bus and various other improvements. Although the PC/AT still ran DOS and didn’t use the full features of the 286, it was much faster than the original PC which was frankly a bit of a tortoise.

Because IBM and other suppliers insisted on a second source for the 80286, Intel licenced the processor to other manufacturers. These included IBM, AMD, Harris, Siemens and Fujitsu. Harris pushed the speed of the processor up to 25MHz, twice as fast as the top-of-the-line Intel 80286 which ran at just 12.5MHz. For AMD, the second sourcing of the 286 gave them an entry into the Intel-compatible CPU market where they are still the only real competition to Intel today.

The 286 certainly moved things forward, but in terms of the PC it wasn’t the technological leap forward that it needed. In 1985, Intel launched the 80386 which could run multiple virtual 8086 real modes… this meant that a PC could run several DOS applications at once which was a key factor in the uptake of Windows rather than MS-DOS in the PC marketplace.

Although Intel officially dropped the 286 in 1991, Harris and AMD continued to develop it and provided some serious competition to Intel’s new 386 for quite a while. Today these 286 CPUs are still used in some embedded systems, and the Renesas CS80C286 is still available today for these applications.

Second source AMD 286 variant

The 80286 established that the PC architecture wasn’t a one-off design, and marked the beginning of a continual evolution of the platform which of course is still with us today. Because it couldn’t multitask DOS programs, its impact was more limited than the 80386 that followed. However, Windows supported the 286 until version 3.1 (launched in 1992). Many 286-based PCs soldiered on well into the 1990s, some even making it to the Internet age with applications such as Netscape Navigator – far outliving the usefulness of the previous generation.

Image credits:
Thomas Nguyen via Wikimedia Commons - CC BY-SA 4.0
Pascal via Flickr – CC0

Intel 80486 (1989)

Intel 80486DX-25

Announced April 1989

Early PCs were slow. Really slow. Even in the late 1980s, many were still based on the decade-old Intel 8086. Successive generations of CPU were better, the 80286 was faster, the 80386 helped to bring in multitasking but it wasn’t until 1989 that Intel finally came out with a processor that could considered as fast – the Intel 80486.

The 80486 (often known as the “486”) built on the architecture of the 80386, combining it with an 80387 maths co-processor, 80385 cache controller plus a whole lot of other optimisations to come up with something that was twice as fast as the 80386 for any given clock speed. Initially launched running at 20 and 25MHz, by 1994 the clock rate was pushed up to 100MHz in the IntelDX2. For users on a budget, the maths co-processor was removed to create the 486SX.

Hand-in-hand with the 486 was the VESA Local Bus (VL-Bus) which was used primarily with graphics cards to bypass the bottlenecks in the old 16-bit ISA bus that most PCs had. This made 486 PCs significantly better for games and other graphically-intensive work, although the VL-Bus itself was very much tied to the 486 architecture and effectively became extinct when the Pentium first came out.

It took until 1990 until the 486 was available in quantity, however the first 486-based computer was the British Apricot VX FT server, launched in September 1989. The 486’s architecture helped to introduce plug-and-play into Windows, and it remained competitive even when its successor was launched, with the cheaper 100 MHz 486 outpacing the expensive 60 MHz Pentium. But of course times would change. Intel kept various models of the 486 in production until 2007. Rival companies also made 486s, some under licence and others reverse-engineered in some way.

It turns out that old processors are somewhat collectable, but generally these tend to be 1970s CPUs rather than later ones. Still, if you find yourself in need of a particular 486 for some reason, you can probably find one on eBay.

As for the name… the 80486 was the last processor of its type to be named with a number, following on from the 8086 launched 11 years earlier. The reason for this was that numbers cannot be trademarked in many jurisdictions, so the next generation was named the “Pentium” which was a nod to the “5” in 80586 if Intel had continued with their naming pattern.

Image credit: Andrzej w k 2 via Wikimedia Commons

Space Invaders (1978)

Space Invaders (Midway version)

Launched June 1978

Forty years ago this month, Japan saw the launch of a simple little arcade game called Space Invaders. The premise was simple – five rows of pixelated aliens marched slowly across the screen while a laser cannon at the bottom tries to pick them off, accompanied with a basic four-note soundtrack and some sound effects. Simple it may have been, but Space Invaders became an enormous success.

The game came at a point when the technology was just becoming good enough to produce a compelling game. The Space Invaders machine itself ran an Intel 8080 CPU (a predecessor of the 8086) with a Texas Instruments chip producing the sounds (this in the same month as the launch of the Speak & Spell). A monochrome monitor in portrait mode gave a graphics resolution of 224 x 256 pixels, and in some versions of the game coloured strips across the screen gave the impression of a colour display when it wasn’t.

As with many classic games of the era, Space Invaders embraced the technical limitations of the hardware. The blocky aliens became a design icon, the simple but hypnotic soundtrack attracted curious onlookers. The fact that the very last invader raced across the screen in an adrenaline-fueled finale was simply a side-effect of the processor having less work to do.

The gameplay was simple enough but compelling, and Space Invaders machine soon started to rake in the money. A lot of money. A machine could pay for itself in a month or even less, and they soon started to pop up in all sort of places worldwide that hadn’t previously dabbled in arcade games, such as supermarkets.

There were two basic formats – creator Taito turned the game into a table-top format and cabinet with a joystick, while US licensee Midway used a cabinet with buttons replacing the joystick. Between them, the arcade versions raked in hundreds of millions of dollars of profit… and from then on there were adaptations for games consoles, home computers and a raft of sequels and spin-offs spanning generations.

Today prices for reconditioned original Space Invader machines can be £4000 or more. Alternatively for a few pounds you can buy an authentic reproduction of the original to play on your smartphone.

Image credit: Wally Gobetz via Flickr

Video: Reconditioned Taito Space Invaders machine

Intel 8086 (1978)

Intel 8086

Launched June 1978

By the late 1970s, Intel had carved out a successful slice of the microprocessor market with the 8-bit Intel 8080 and Intel 8085, but rivals such as the Zilog Z80 and MOS 6502 were eating into that share. Intel had been trying to design a radical 16-bit CPU – the iAPX 432 – since 1975 but that was still nowhere near completion.

As a quicker way of getting a 16-bit processor to market, Intel took some of the features of the existing 8085 and greatly expanded on it, making it much more powerful while maintaining some level of backward capability. The new 8086 was developed by a small team in just two years - the iAPX 432 took six years and a much larger team.

In 1978 the 8086 was ready to hit the market, clocked at 5 MHz and priced at under $90 a unit. It soon found its way into professional and scientific computer systems, but it finally got a big break in 1981 when the IBM PC was launched with a cut-down version of the 8086 called the 8088 inside.

The IBM PC and its clones ensured the success of the 8086 and 8088, and several generations followed. In June 2018 – to celebrate the 40th anniversary of the 8086 – Intel announced a special edition of their current processor called the Core i7-8086K which is a 64-bit CPU clocked at 5 GHz, with 6 CPU cores.

The 8086, its descendants and compatible processors from rivals sold in huge quantities… not bad for something that was a bit of a stopgap. The iAPX 432 turned out to be too much of a technological leap for any company to make in the 1970s and ended up as a disaster. In the end, the simpler solution to the 16-bit problem was the more effective one. There’s probably a lesson in that.

Image credit: Thomas Nguyen via Wikipedia