The Raspberry Pi Thread

[sje]

There is a soon-to-be-released computer for US$25/UK£15. It is about the size of a deck of playing cards and connects to your keyboard (USB) and your TV (HDMI).



For the computer, see: http://www.raspberrypi.org/faqs

For the chess program, see me later for a port of CookieCat to the 700 MHz ARM processor used by the Raspberry Pi.

[Adam Hair]

[mclane]

i like the idea to build an extremly cheap and primitive computer for the people all over the world that needs only a TV set.

i am sure it will be easy to port a few strong chess programs on it to bring chess into the world too...

[sje]

i like the idea to build an extremly cheap and primitive computer for the people all over the world that needs only a TV set.

i am sure it will be easy to port a few strong chess programs on it to bring chess into the world too...

The machine still needs a power source, a keyboard, a mouse, and some cables. A Compact Flash card is needed, as I don't think one is supplied.The Ethernet version of the board including doubled RAM (256 MB) is an extra US$10. So maybe US$75 total for a well equipped unit.

The doubled RAM is a good idea, as I'll guess that the Linux kernel and common daemons will eat about 64 MB. Virtual memory swapping to a CF card is something to be avoided were possible.

A headless version with only cabled Ethernet would be slightly cheaper, perhaps about US$50. Twenty or so Raspberry Pi would make a nice Beowulf cluster with 14 GHz of processor bandwidth for US$1,000.

However, existing programs that are x86 or X64 dependent won't run on an ARM, so they will need some modifications.

It would be very nice to see chess program authors post versions of their programs marked "Raspberry Pi compatible" or even better, "Raspberry Pi Beowulf compatible".

[lucasart]

i like the idea to build an extremly cheap and primitive computer for the people all over the world that needs only a TV set.

i am sure it will be easy to port a few strong chess programs on it to bring chess into the world too...

The machine still needs a power source, a keyboard, a mouse, and some cables. A Compact Flash card is needed, as I don't think one is supplied.The Ethernet version of the board including doubled RAM (256 MB) is an extra US$10. So maybe US$75 total for a well equipped unit.

The doubled RAM is a good idea, as I'll guess that the Linux kernel and common daemons will eat about 64 MB. Virtual memory swapping to a CF card is something to be avoided were possible.

A headless version with only cabled Ethernet would be slightly cheaper, perhaps about US$50. Twenty or so Raspberry Pi would make a nice Beowulf cluster with 14 GHz of processor bandwidth for US$1,000.

However, existing programs that are x86 or X64 dependent won't run on an ARM, so they will need some modifications.

It would be very nice to see chess program authors post versions of their programs marked "Raspberry Pi compatible" or even better, "Raspberry Pi Beowulf compatible".

rest assured there will be a DoubleCheck for Raspberry as soon as I can get hold of a GCC port for it. And I'm sure if it's powered by GNU/Linux that there must be one

[sje]

rest assured there will be a DoubleCheck for Raspberry as soon as I can get hold of a GCC port for it. And I'm sure if it's powered by GNU/Linux that there must be one

I believe that the current gcc on just about any desktop/notebook can cross compile to ARM11.

I'll be working on compiling CookieCat natively as the main motivation for the Raspberry Pi is to help teach programming; CookieCat can help here with teaching Pascal and chess coding. The idea is that some students with a Raspberry Pi may not have a separate desktop/notebook and will need a native port of the Free Pascal compiler.

I predict that the Raspberry Pi will sell very, very well.

[sje]

Wikipedia entry: http://en.wikipedia.org/wiki/Raspberry_Pi

I'm sad to see that no real time clock chip is included. Apparently, a networked Raspberry Pi will have to query a time server as part of the boot sequence soon after a network interface is established. The alternative is to either manually set the date and time or run like it's January 1st, 1970.

Ubuntu is not included in the default set of supported operating systems. This is not too surprising as Ubuntu has gained a lot of bloat over the past few years.

[sje]

More data:

1) Ubuntu has been dropped as a official option because Ubuntu is no longer interested in supporting the ARMv6 architecture. This is reminiscent of Ubuntu's dropping PowerPC support a few years back; unofficial PowerPC enthusiast support continues.

2) The dozen or so GPIO pin pairs can be configured to handle all the common microcontroller communication protocols. RS-232 is included, so an old style terminal can be used.

3) While no RTC (real time clock) chip is present (no NVRAM, either), it would be easy to connect one via a serial (SPI, maybe) to one of the GPIO pin pairs. Of course, the CPU has a periodic interrupt, so the Linux kernel can keep track of the time as long as it's given a correct starting point. There is some talk that the "second" version of the board coming maybe in late 2012 will have an RTC and perhaps some other goodies.

4) The project includes planned support of Lazarus, the usual IDE for Free Pascal. This implies support for the Free Pascal compiler, so my CookieCat should be good to go. All of the 2, 3, and 4 man tablebases will fit easily on the CF card. And with Linux, networked file sharing is supported, so all the tablebases could live on a desktop server. I did something like this using NFS long ago; it worked but (at that time), the NFS connection per process was limited to a maximum of 20 simultaneously open files.

5) The gcc/g++ toolchain will be present, so Bob can port Crafty to a machine not much bigger than a credit card.

6) The CPU's video hardware can drive a 1920x1080 HD output via HDMI. There's a lot of power in the video hardware and with the right libraries it can be used for general vector computing.

7) IEEE floating point is done via emulation. But for chess, who cares?

8) Converters are available to map the HDMI output to DVI and VGA. What happens to the sound, who knows?

9) There is an output to drive an LED display directly and possibly an LCD touchscreen. Someone should tell Steve Blincoe about this so he can soon add yet another dedicated chess computer to his collection.

10) The board does not come with a case, but there is an expectation that third party suppliers will provide this and maybe some other missing pieces.

11) The wired Ethernet NIC as 10/100 Mbps; I don't know if it has auto polarity sensing as does 1000baseT. This has some importance for wiring a cluster.

12) The Beeb's story: http://www.bbc.co.uk/news/technology-16316439

[sje]

Even before the first version has been put on the market, there has been much discussion about clusters made from Raspberry Pi boards. As can be expected, there is the usual conflict between more features and minimal cost.

http://www.raspberrypi.org/forum/projec ... n-advanced

I'm going to buy a Raspberry Pi as soon as I can for testing. After that, I'll probably get eight more and build a cluster connected via 100baseT in a switched network. The cluster boards will be headless and commanded by a separate controller on the LAN.

The only problem I foresee is that I might have a long wait getting the boards as the British schoolkids have priority. Delivery might take months.

Incidentally, a cluster of Raspberry Pi boards is officially called a "bramble".

[mclane]

what do you do with such a cluster ?