31 August 2011 00:20
£15 ARM Linux computer before Christmas
The RaspberryPi Foundation, which aims to put computers in front of children for £15, has taken delivery of 50 engineering prototypes, and intends to get the final version to customers by the end of the year.
Based in Cambridge and founded by six high-tech high-flyers, the foundation’s aim is to cure the programmer shortage by inspiring people to take up computing in childhood – as Sinclair Spectrums and BBC Micros once did.
“In 1996, the average skill set of someone entering university was a couple of machine code languages and some hardware hacking experience. Now if we have someone that has written a web page we are lucky,” Foundation founder and former University of Cambridge lecture Dr Eben Upton told Electronics Weekly in May.
Seeing its potential outside the UK, educators from the developing world have already beaten a path to the Foundation’s door, cash in hand.
“We can give you a 700MHz ARM, more graphical performance than an Xbox 1, the ability to plug in a 1080p Blu-ray, and a thing that is actually an exciting product for real-life adults,” Upton told the Educating Programmers Summit, run by Codemanship recently. “It is not an educational toy, it is a thing that could replace your Apple TV.”
According to the Foundation, on the day it arrived, the team booted Debian Linux on the Alpha hardware.
This said, Ubuntu is the Linux flavour favoured by RaspberryPi, but it looks like hardware resource greed is ruling it out for the moment in favour of Debian.
The 50 ‘Alpha’ boards are around 20% larger than the intended final board which is likely to be the size of a credit card.
To validate the schematic, it is electrically identical to the final board, but has six layers rather than four and uses expensive blind and buried vias.
Original plans had the computer looking very much like a flash stick – a thumb-sized rectangle with a USB connector on one end, plus a DVI connector on the other end to hook up a monitor.
While the circuit will still fit in that size, the number of IO connectors found necessary has caused the shift to credit card size.
Alpha has an RJ45 network jack, dual USB, digital TV via HDMI, analogue TV through an RCA socket, plus analogue audio and a power socket.
“We can plug into DVI monitors, HDMI TVs, old analogue TVs,” said Upton at the programmers summit. “Old analogue TV is the kind of thing we are going for, we want the 1980s idea of a box being a machine that turns your television into a computer.”
The source of the 700MHz ARM-based application processor, which includes graphics and video processing, had initially to remain a secret.
Now the foundation has revealed it to be the Cambridge-designed Broadcom BCM2835. Upton currently works for Broadcom in Cambridge.
To give some idea of the performance available from this silicon, the Raspberry Pi has posted a video on its blog of the Alpha board running the fast-paced 3D-rendered game Quake 3.
£15 ARM Linux computer before ChristmasPlaying games is the bait that the Foundation thinks got the Spectrum generation into programming.
“There is an energy barrier at the start of the learning curve,” said Upton in May. “With the Spectrum or the BBC Micro, even if you only wanted it to run a game, you turned it on and it immediately said ‘BASIC’ and you could write
>10 print “Hello world”
>20 goto 10.
A lot of us got sucked in by that and became programmers.”
128 or 256Mbyte of system RAM is package-on-package mounted on top of the application processor.
The target price of £15, which is actually a more international valid $25, includes 128Mbyte.
“For $35 we can also add to that another 128Mbyte of RAM and we can add a network connection,” said Upton. “Based on feedback we have received on-line, most of our business will be here.”
Completing Alpha’s chip line-up is LAN9512 chip from SMCS which provides the two 480Mbit/s USB connections and 10/100 Ethernet
“Following the example of the BBC Micro, we intend to launch both a Model A lacking the LAN9512 and with 128MB of RAM; and a Model B including the LAN9512 and with 256MB of RAM,” said the foundation.
Model A also only gets one USB port.
Mounted on the back will be a full-size SD Card slot.
In keeping with the whole tiny size thing, why not microSD?
Full-size slots are more robust, said Upton, and microSD cards (15x11mm) are just too easily lost.
When will Model A and B credit-card-size RaspberryPi computers be available for purchase?
“We are trying to get it out by the end of the year,” said Upton.
Alpha hardware will be on-show at the Transfer Summit open-source forum and conference at Keble College in Oxford on September 7-8.