Thursday, 28 April 2022

Raspberry Pi (2012)

Available April 2012

Single board computers were common in the early days of microcomputers, with the KIM-1 offering a relatively low-cost way of playing with the then-new 6502 CPU and later devices such as the Acorn System 1 made it cheaper still. But single board computers appealed most to hobbyists, and as technology developed so did microcomputers, eventually evolving into complete systems that were easier for novices to use.

Original Raspberry Pi Model B
Original Raspberry Pi Model B

As the decades rolled on, the amount of computing power that could be squeezed into a board computer grew. First came Arduino, a series of open source board computers that could be used for microcontrollers. A few years later, TI came up with the BeagleBoard which was a general purpose computer on a single board. But perhaps the best know modern single board computer is the Raspberry Pi, shipping to customers in April 2012.

Unlike some other designs, the Pi was a complete system on a compact board. With built-in USB, video and networking ports all that was required was a memory card with an operating system and a monitor, keyboard, mouse and power supply. These are all pretty common peripherals, and in most cases Pi users could just re-purpose old equipment used elsewhere. The Pi didn’t come with a case so a cottage industry started up making them, all of this echoing the rather do-it-yourself approach of the original Apple I.

The first Raspberry Pi models were announced in February 2012, coming to market in April the same year. Like the BBC Micro, there were two launch models of the Pi – A and B. B was the most popular, based around a Broadcom chipset that included an ARM CPU, RAM and all of the other silicon needed on a single chip. But perhaps the biggest breakthrough was the price – this complete computer system cost just $25 or the local equivalent for the simplest model.

Coincidentally, the ARM CPU in the Pi was originally designed by Acorn, whose experience with the 6502 (starting with the Acorn System 1 board computer) inspired them to create an inexpensive, simple but very fast processor based on similar principles.

The target market was initially education – instead of expensive laptops, students could simply plug their own Pi into a PSU, monitor, network socket, mouse and keyboard and do whatever they wanted with it. The easily swappable memory card meant that different configurations could be experimented with easily. But the appeal turned out to be far greater, everyone from hobbyists to engineers wanted to play with one and the Pi became a significant success. Raspberry Pi devices can be seen in almost any application from controllers to servers, often performing tasks as well as machines costing hundreds of times as much.

A decade on, the Raspberry Pi is still going strong. Later models offered more ports, a faster processor and more memory and even cheaper models such as the Pi Zero and Pi Pico slotted into the range below the fully-featured Pi. A wide range of peripherals are available for almost any application, and OS support has grown from Linux-only to include Windows 10 IoT and even a version of RISC OS (originally designed for the very first ARM-based computer, the Archimedes).

Raspberry Pi emulating a DEC PDP-8 and PDP-11
Raspberry Pi emulating a DEC PDP-8 and PDP-11

Millions of devices and a decade later, the Pi has proved to be an antidote to the anodyne world of modern personal computing. The Pi helped to re-ignite some of the early hacker ethic of early micros and taught a new generation that what they could do with a computer was only limited by their imagination. Not too shabby for just $25.

Image credits:
osde8info via Flickr – CC BY-SA 2.0
Wolfgang Stief via Flickr – CC0

Saturday, 23 April 2022

GRiD Compass (1982)

Released April 1982

Even though practical microcomputers had only been around for a few years by 1982, there was a growing market for portable devices such as the Kaypro II which offered all the computing power you probably needed in a luggable package.

Back then people accepted that a portable computer would weigh something like 13 kg and come in a huge case. Practically speaking you’d typically carry it between a desk and car. Unlike modern “laptop” computers, most portables of the early 1980s would possibly break your knees if you tried to use them on the sofa.

GRiD Compass
GRiD Compass

The first practical laptop computer is widely considered to be the GRiD Compass. A clamshell on the front of the device held a 320 x 240 pixel electroluminescent display and a keyboard in a format instantly recognisable today. Although the display was relatively small, it was sharp and clear compared to early LCD panels and the limited resolution was actually pretty competitive with most computers of the time.

Inside was an Intel 8086 CPU with an 8087 maths coprocessor, but this was no DOS-compatible computer. Instead the Compass ran a proprietary OS called GRID-OS which was menu-driven and quite friendly. One novelty was storage – the Compass used magnetic bubble memory giving 340Kb of non-volatile storage. Most production systems also included a modem, and an IEEE interface bus was standard. The lightweight but strong magnesium alloy case contributed to the relatively light weight of around 5 kg.

This was a highly advanced machine, and it came with a substantial price tag starting at $8500 in 1982 money which is around $25,000 today. OK, it is possible to spend more than that on a computer today (a high-end Mac Pro can cost $60,000 or more) but that was nearly six times the price of the Kaypro and to be honest it couldn’t do as much for a typical end user.

Where it did find a niche was in government sales. The tough but lightweight design lent itself well to military applications, and the Compass was also certified for use on board the Space Shuttle. Large corporations were drawn to it as a practical and highly portable device, but few found their way to private users due to the high price.

GRiD Compass running a spreadsheet
GRiD Compass running a spreadsheet

This was the first in line of several GRiD systems, and on top of healthy sales they also owned a patent for several of the elements of the clamshell design, meaning that other laptop manufacturers had to pay GRiD a fee for each system built. GRiD was taken over by Tandy in 1988 followed by a management buyout in 1993 which moved the company from California to the UK. The company – now called GRiD Defence Systems – still makes ruggedized laptops and other hardware.

The Compass set the pattern for all modern laptop designs, years before they became commonplace. Today first-generation GRiD Compass systems are very rare and you can expect to pay between £5000 to £10000 for a working system.

Image credits:
Cooper Hewitt, Smithsonian Design Museum
Niall Kennedy via Flickr - CC BY-NC 2.0

Thursday, 14 April 2022

Sinclair ZX Spectrum (1982)

Introduced April 1982

If you were a British child of the 1980s, the chances were that you possessed one of the holy trinity of the BBC Micro, Commodore 64 or the Sinclair ZX Spectrum. A rivalry leading to many playground arguments, these three machines duked it out for years with no clear winner.

Sinclair ZX Spectrum

Out of the three, the cheapest and most popular (for a while) was the Sinclair ZX Spectrum. Sinclair’s follow-on to the ultra-low-cost ZX81 launched the year before, the Spectrum added rudimentary but usable colour, graphics and sound in a package with either 16kB or more desirably 48Kb of RAM in a stylish package – all at a very attractive price.

Like the ZX81, the Spectrum was based on a Z80 processor. But where the ZX81 struggled to do anything due to its clever-but-simple design, the Spectrum was highly competitive with the new generation of early 1980s home computers.

It wasn’t a big machine – roughly the size of a sheet of A5 paper and weighing around 550 grams – but Rick Dickinson’s industrial design consisting of a black case, grey keys and the 1980s-on-a-stick rainbow flash on the corner looked far more impressive than the competition. Those keys were something else though – each one performed up to six functions in the Spectrum’s capable BASIC environment, but the strange rubberiness of the keys felt like touching dead flesh.

The multifunction keys bear some examination. All the BASIC keywords were assigned to a key which would activate depending on context, or with the CAPS SHIFT and SYMBOL SHIFT keys. This layout was first seen on the ZX80 and while it reduced errors and made programming more accessible, it was becoming more fiddly as the version of BASIC evolved. The Spectrum’s version of BASIC was pretty sophisticated – not as good as the one in the BBC but better than the Commodore 64. Budding programmers took to the Spectrum and coded furiously from their bedrooms.

As standard the Spectrum loaded and save programs to a cassette, which was quite slow. Video output was to a domestic TV set, so the Spectrum could easily plug into what you probably already had in the house. The desirable 48Kb version cost just £175 at the time (equivalent to around £650 today) but you really didn’t need anything else if you had a TV and cassette recorder.

Like the BBC, the Spectrum could address only 64Kb of memory. The ROM was simpler than the BBC, taking up just 16Kb which left up to 48Kb of RAM available. The Spectrum’s curious colour graphics mode didn’t eat up much memory either, meaning that there was quite a decent amount of RAM available for programs, something that the BBC struggled with.

The colour graphics were rather strange. The 256 x 192 pixel resolution could display up to 15 colours, but you could only have one foreground (INK) and one background (PAPER) could in each 32x24 pixel character grid. This made it tricky to code colour games (for example) but it was very memory efficient. Sound output was fairly simple with a one channel output, but it was good enough for most purposes.

Like the ZX81 and ZX80, and edge connector on the back of the machine allowed access to pretty much all hardware functions. Sinclair’s official accessories on launch included a tiny thermal printer and the ZX Microdrive, which was a high-speed tape cartridge which was plagued with delays. Popular third-party addons included the Kempston Micro Electronics joystick interface but also various adapters for disk drives, speech, serial and parallel ports and perhaps most important a variety of aftermarket keyboards that improved on the Spectrum’s unpleasant chicklet affair.

Spectrum with daisy-chained ZX Microdrives and sound enhancements
Spectrum with daisy-chained ZX Microdrives and sound enhancements

The Spectrum was an enormous success - the combination of pricing, features and the brand recognition of the “Sinclair” name were key factors. Success bred success with huge variety of games and other applications along with hardware enhancements coming to market. Few competitors had a fraction of the third-party support that the Spectrum did.

1982 and 1983 were probably the peak years for the home computer market in the UK. Sinclair found itself up against increasing competition from less well-known machines which were often better (though rarely cheaper). In 1984 the Spectrum+ was launched, essentially a 48K Spectrum in a Sinclair QL-style case. A 128Kb version dubbed the Spectrum 128 was launched the year after, using memory paging to break the 64Kb limit. In 1986 Sinclair found itself in difficulties and was bought by Amstrad who styled new models after their popular CPC range leading to the Spectrum +2 with an integrated cassette recorder in 1986 and the Spectrum +3 which included a built-in 3” floppy disk drive, launched in 1987. This +3 was the ultimate development of the Spectrum platform, capable of running CP/M but it wasn’t 100% hardware compatible with the original which caused problems. The last Spectrum models in production were the +2B and +3B which were basically hardware fixes of previous versions, production ended in 1992 giving the Spectrum platform an impressive ten year lifespan.

ZX Spectrum +3 with 128Kb RAM and a 3" floppy drive
ZX Spectrum +3 with 128Kb RAM and a 3" floppy drive

In addition to the official Sinclair version, licensed and unlicensed clones proliferated – notably licensed variants made Timex in the US and Europe, and a huge number of bootleg clones in Eastern Europe and South America into the 1990s. In the 2010s there were several attempts to recreate the Spectrum with modern technology, perhaps most significantly with the ZX Spectrum Next.

Despite the success of the Spectrum in the market, ultimately it was something of a dead end – even though fondness for the platform lingers on four decades later. However, the significance of the Spectrum was profound in the markets it succeeded in: this low-cost, easy-to-use and versatile device inspired a generation of programmers and computer enthusiasts, many of whom went on to carve careers out in the IT industry. This simple but effective machine not only help to shape lives, but also whole economies. Not bad for a cheap computer with a nasty rubber keyboard.

Image credits:
Bill Bertram via Wikimedia Commons – CC BY-SA 2.5
ccwoodcock via Wikimedia Commons – CC BY 2.0
ccwoodcock via Wikimedia Commons – CC BY 2.0