Toshiba AC100 Smartbook – Underdog to Winner in 5 Months

I have had the Toshiba AC100 for as long as I have had the Genesi Efika MX, but on top of suffering some of the same frustrating limitations, the stability of the drivers for it in the Linux kernel just wasn’t quite up to the task until recently, and few sane people would consider using Android on a device without a touchscreen, as Toshiba appear to have envisaged.

Since Efika MX‘s major problems – the painfully low screen resolution (a problem it shares with the AC100) and the completely unusable touchpad – turned out to be easily fixable, the AC100 went on the shelf for a while. This was a shame since the AC100 had about three times the CPU power of the Efika MX (dual core Cortex A9 1GHz vs Efika’s single core Cortex A8 800MHz), but having a fully working, usable system was more important.

All that changed recently. ChromeOS 2.6.38.3 kernel brought with it more support for Tegra2 based devices, including the development board that the AC100 is based on, and shortly afterwards thanks to the awesome people in the AC100 community, a lot of things fell into place, including stable NVEC support (what keyboard/mouse/LEDs are connected to on the AC100) and sound support. But most importantly for me, the recent kernel also came with the kernel level display panel setup. No longer entirely at the mercy of what the boot loader configures, it became possible to use a higher resolution screen!

So, I carried out the upgrade to 1280×720 using the same TFT panel that I used to upgrade the Efika. All that was required was a small kernel patch. Without a change to the boot loader data the machine still starts up in 1024×600, and the kernel boot-up output is corrupted until the console font is re-set, but since setfont is called very early during the Fedora boot-up sequence, it is a problem that isn’t hard to live with. From there on, everything works absolutely fine in 1280×720. An article on the details of the upgrade procedure and the required kernel patch will follow shortly.

The nvidia binary driver works OK-ish – most of the time, but it isn’t particularly stable – every once in a while you will do something that causes the screen output to get partially corrupted. This is not related to the higher resolution, all the problems occur at 1024×600, too. Unfortunately, it doesn’t look like nvidia are showing that much interest in improving this quickly, and since their approachability and interest in helping their user community is as non-existent as ever, I wouldn’t expect driver improvements any time soon. Still, for normal use the standard unaccelerated frame buffer driver is rock solid, and the acceleration in the nvidia driver does work well enough if you want to play videos at full screen resolution, and there is even a Tegra accelerated version of flash available so YouTube works, too. All of this is a considerable improvement on the Efika MX.

Power management is also completely functional on the AC100 now, so it’s battery life is virtually identical to the Efika MX.

It is amazing how much difference 5 months can make. AC100 went from being the underdog to being an outright winner. It now matches the Efika on battery life and screen resolution, and soundly beats it by a large margin on the touchpad (the touchpad on the AC100 is actually extremely good), performance and features (no YouTube without Flash).

Best of all, it is no more expensive than the Efika MX. Here in UK – new ones can be had for as little as £170, which is less than you’ll pay for an Efika with a non-US keyboard.

In fact, the price/performance in terms of CPU power is actually better on the AC100 than it is on the SheevaPlug, and that’s before the added convenience of also having a screen/keyboard attached for troubleshooting. Because of this, AC100s are now used for extending my ARM compile farm.

9 thoughts on “Toshiba AC100 Smartbook – Underdog to Winner in 5 Months

  1. Hi,

    I’ve been thinking about buying the AC100, and the abysmal resolution was one of the things stopping me. So I’m extremely happy you found a way to fix that shortcoming :D. Could you disclose the exact screen model you fitted there? Also, do you think it would be possible to fit in a screen with an even larger resolution – let’s say, 1600×900? The official Tegra 250 specs say the LCD controller supports up to 1680×1050, so this could possibly work.

    This lappy would become an extremely cool piece of gear with a 1600×900 screen. Now I wonder how much work would it be to make ArmedSlack run on it ;-).

    Cheers

    • I will be writing an article on the screen upgrade shortly, but in the meantime, have a look at the previous article about upgrading the Genesi Efika MX Smartbook – I used the same screen.

      The problem with fitting a higher resolution screen is that the highest resolution available on a 10.1″ 16:9 panel is 1366×768, and there is only one such panel available that I could find. Unfortunately, it didn’t work – but that could just be because the panel didn’t like the 1024×600@50Hz mode that the boot loader initializes to. Either way, 1366×768 panel didn’t work, but 1280×720 did, so I went with that. I might try the 1366×768 panel again and see if it works OK now that the kernel will try to initialize it to 1280×720@60Hz.

      As for 1600×900 or 1680×1050 – that would work if you actually had a panel in that resolution in 10.1″ size, but having looked quite extensively, I have found no evidence of such a thing existing.

      • Thanks for your answer. I think I’ll let it pass, though. I’ll wait for some Tegra 3 goodness that will hopefully come to the market in laptop form soon. And with a more reasonable amount of RAM.

        Then again, here in Poland you can get a full-blown AC100-E for 700PLN (at current exch. rate ≈ £130). Crap, my wallet is starting to feel uneasy again… 😉

        • It gets even better – I just put together an overclocking kernel for it. At the moment I only tested it for a couple of hours at 1.2GHz (up from 1.0GHz), but I can’t seem to destabilize it at default voltage so it’s looking quite good. 🙂

          • Believe me, if this thing had at least 1GB of RAM, I’d already have it. But unfortunately, 512MB means quite a lot of swapping in normal use – and flash memory has a limited amount of write cycles. Which wouldn’t be so bad if you could just replace it with new one – but here, it’s an eMMC soldered to the board! Which means that bricked SSD = bricked lappy. Ouch.

          • There is always zram and zcache. They are stable enough for normal use and I find that in normal use (half a dozen terminals and Firefox) the swapping never exceeds zram capacity. And I run Fedora 13 (soon going to switch to my RHEL6 ARM port called RedSleeve as soon as the next rebuild stage of it is completed) with XFCE. I haven’t tried LXDE yet, but plan to, soon. Also, I’m working on getting Chromium to build on a Fedora, which should be a lot more compact than Firefox.

            I know 512MB of RAM is not ideal, but it is just about livable with. You should be able to get 1GB of RAM on one of these, but you’ll need help from someone who has BGA soldering equipment. I’ve been meaning to look into it, but it’s not cheap – it’d probably cost a similar amount as the AC100 itself.

          • Forgot to mention – I’m running Linux off an SD card, rather than from internal eMMC, so the eMMC only ever gets written to when I update the kernel image. You could equally easily run off a USB stick, too. I’ve been pondering tapping an additional USB line from the internal mini PCIe slot (the slot only has USB wired in – PCIe isn’t wired up despite the fact that Tegra2 does in fact have a PCIe controller built in) up to one of those tiny USB micro-SD card readers and running the OS from that to free up the SD slot, but I never bothered implementing this – it is far easier to just use an external USB card reader. 🙂

  2. Great job! Can’t believe that you managed to upgrade the screen. Is there a notable difference compared to the original lower resolution display. Looking forward to the guide.

    Also it seems confusing to me why there are not more ultra slim, fanless, arm powered and cheap notebooks like this, specially since the processor/gpu is still much better than lower end atoms for tasks such as hd video.

    • Yes, it is quite noticeable. The difference is between useless and usable. 1024×600 is really insufficient for just about anything, IMNSHO.

      As for why there aren’t more such things out there, I’m sure you can pick some of many conspiracies. 😉 But I suspect the real, boring reason is that running non-Windows is beyond most people.

      And you will find that a Cortex A9 beats the performance of Atoms even per clock, let alone per Watt.

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