Thursday, 26 May 2011

I've been a little busy...


I've not posted for a little while, but I have a good reason for it I promise. It's because I've bought a new toy. It's battery powered, goes about 15mph and is brilliant fun. Can't guess? It's a Sinclair C5.

Developed in 1985 by Clive Sinclair, this was "the vehicle of the future." Sort of. Basically a three wheeled tricycle with an electric motor to push you along.

It's very good fun.

Saturday, 12 March 2011

WM8505 take 2

I spotted another of these machines on eBay, it was labelled as a VT8500 and apparently had a broken keyboard. It was £20 shipped so I took a chance on it.

Take a peek at it on my Flickr, booting Debian.

Upon getting it out of the box and hooking it up to the mains, I was inclined to agree with the seller's claims. Then I opened it and noticed that there wasn't a VT8500 chip on the board; there was a WM8505 staring back at me, complete with 2GB of NAND flash.

This was interesting, thought I, so I grabbed a WinCE recovery image, booted it up and noticed that the keyboard worked... but it wouldn't install.

Long story short, a flash for the "Sylvania Smartbook" correctly re-loaded WinCE onto the netbook, and moments later I had installed Android instead.

After deciding that Android, whilst it's probably brilliant on a tablet, really isn't suited to a netbook like this, so I've gone and ordered one of these SDHC cards. Make sure you get Class 10 or faster (I've linked to Class 10 there) as they're about the same price and make quite a bit of difference in speed!

When it arrives I'll be starting a full write up of how to get these things set up with linux. Perhaps even without another computer being involved. We'll see!

I've begun a NAND-free writeup which I'll release soon, it's almost complete, and as soon as I can flash my SPI chip then I'll finish that off too. If I don't get around to doing that any time soon, I might release it anyway, for someone else to finish, perhaps?

So far I've been completely unable to get the Debian installer running on either of my netbooks, but there's honestly very little point of installing it to the 2GB flash when you can run everything from an 8GB Class 10 (way faster) SDHC card...

Saturday, 5 February 2011

The little laptop, again.

It's been ages since I last made a post, I'm sorry about that!

The WM8505 machine I've got has a few bigger issues than just u-boot. I've managed to confirm that I've broken w-boot too. This means that reflashing with JTAG without knowing the physical memory map of the chip is actually impossible. Therefore, I'm going to remove, re-flash and resolder the 4Mbit SPI chip.

I'll keep you posted as to how it turns out!

In other news, I'm getting to grips with SPICE circuit simulation, which is rather fun. If you're at all interested in that sort of thing then please check back soon, as I'm thinking of writing a few short tutorials. Let me know if you'd like that!

EDIT: Grammar

Wednesday, 12 January 2011

WM8505

A few things I didn't explain in the last post:

WM8505 is the name of the system-on-chip which this laptop uses. It's ARM920 based, and there's a great following of people trying (and succeeding) to do interesting thing with them. Some interesting links:

VIA ARM SoC based netbook forum
Slatedroid - a forum for duscussing tablets made with the same, and similar, chipsets.
Discussion on slatedroid regarding rewriting the flash chip to "de-brick"
Project gus - another blog related to this chipset (and other things)
Comment on projectgus regarding JTAG use


And some more pictures!

Here's the display unit and display. It's a pretty bog standard 7" LCD, HannStar branded. I can't seem to find a datasheet for this so I won't be able to use it for anything else unless I'm really patient with a logic analyser (unlikely).

And here's my MAX233 Logic level converter. You don't have to make them yourself, there're loads available from other sources (ebay and the like). The easiest way to make one is to get a usb-mobile phone lead like this and cut the phone end off. Then you can just connect it directly, as the cable contains the level converter. If you're planning on doing that, this link will be useful (via http://www.nslu2-linux.org/wiki/HowTo/AddASerialPort).


WM8505

I've bought a new toy, it's one of those little 7" laptops which run Windows CE.

No, that doesn't sound much fun. However, when you look at what it actually is, you realise why it's a little more fun than you might think...

As you can see, the first thing I did was take it apart to get to the interesting bit. The motherboard!

Yep, that's a wifi dongle on that wire. It was passed up through the hinge and stuck (with sticky pads) to the top left of the case where there was a space. I guess that was to improve range. (Many other boards I've seen have the dongle stuck to the motherboard instead - you'll see why this one isn't like that in the next few photos).

This is the interesting side. Notice the small black square on the left hand side. It's a USB port as a 4-pin header. What might plug in there one might think? Well this is what I took out of it:

 Yes, it's just a USB flash disk with a pin header rather than a USB port. This would possibly be a cost saving to the manufacturers over the NAND chip which they had in previous models? That's the only explanation I can think of, but it doesn't make sense, as the USB flash drive has a NAND chip of the same pinout as the empty socket on the CPU daughterboard, as seen below.
This picture's got a number of interesting things in it. The bottom right shows a 4 pin connector, this is the serial port. I've made up a level shifter so I can inspect what's going on from another computer, but it could be useful for other things in the future... The other interesting thing in this picture is the JTAG pins just below the CPU. These are of great interest to me currently as I've managed to mess up the contents of the SPI flash chip (the chip to the left of the pins, a 250401 - 512Kbit, similar to a W25X40 which some of these laptops use instead). JTAG will allow me to rewrite the bootloader (hopefully!) and be on my merry way again.

When it does work, I intend on hacking a few extra peripherals onto it, mainly via. USB. I've found that you can get USB Hubs without ports soldered onto them which should be easy to hack apart and fit into some unused space. Despite this laptop being incredibly small, there's still quite a lot of space to play with. The only concerns I have are heat and battery life... But I should be able to replace the flash disk with the guts of something like this and add a tiny bluetooth dongle.

The next steps from there are proper kernel drivers for power management and a bigger battery.

The source is available, however, so that shouldn't be too hard, given enough time...

That should whet my appetite for now, and hopefully yours too. Why not follow my blog to see if anything interesting amounts from this acquisition. I'll certainly be adding more pictures soon!

Tuesday, 7 September 2010

Haiku!

I installed Haiku R1Alpha2 onto my desktop PC* last night. I've not tried it for a little while, and you know what? It's completely usable! All the basics work, and work well. Video, sound, power management, networking etc. My TV card doesn't work (WinTV PVR-150) and neither does my bluetooth dongle, but it's as usable now as BeOS R5 was (with slightly limited application support, I can't get some of my old favourites to work; BePac gives an error about fonts, SoundPlay says something's missing).

I'm really looking forward to using this full time. I have a ThinkPad X30 which should run it quite well too :-) I'd better get to helping them out and fixing some bugs! (I'll start small)

I miss BeOS, Haiku's reminded me how awesome it was. The new WebPositive browser has made quite a difference too, it's much better than NetPositive was, and more stable than FireFox.

*It's an AMD Athlon XP if you're curious, 640MB DDR RAM, 80Gb PATA HD, ATI Radeon 9520 (I think)

Monday, 23 August 2010

mbed

I recently acquired an mbed board. This is a great little board, I got it up and running some little demos in no time at all. There's no software to install to use it as everything's done online. I can see great things for this in future projects.
It's a great system for testing things, ensuring code works and just playing around, but if I wanted to make something production-worthy then I'd prefer to make my own board up I think. I'll see how I go with it, hopefully I won't blow it up. The replacement cost isn't as small as a simple PIC!