XO Gen 1.5

[John Watlington]

OLPC is excited to announce that a refresh of the XO-1 laptop is in
progress.  In our continued effort to maintain a low price point, OLPC
is refreshing the hardware to take advantage of the latest component
technologies.  This refresh (Gen 1.5) is separate from the Gen 2.0
project, and will continue using the same industrial design and
batteries as Gen 1.  The design goal is to provide an overall update
of the system within the same ID and external appearance.

In order to maximize compatibility with existing software, this
refresh will continue with an x86 processor, using a chipset from
VIA.  The memory will be increased to 1 GB of DDR2 SDRAM, and the
built-in storage will be 4 GB of NAND Flash with an option for 8 GB
(installed at manufacture).

The processor will be a VIA C7-M [1], with plans on using one whose
clock ranges from 400 MHz (1.5 W) to 1GHz (5 W).  The clock may be
throttled back automatically if necessary to meet thermal constraints.

The enabling chipset is hot off the fab line, the VX855 [2].  This
single chip provides the memory interface, a 3D graphics engine, an HD
video decoder, USB, SDIO, and other system interface and management
functions, in a low power and small footprint package.   One change
induced by the chipset change is a move from AC'97 to HD Audio.
This brings higher sampling rates and allows an upgrade to a stereo
external microphone (and DC sensor) input.

The CaFE chip is being retired, and replaced with an external Flash
management controller, possibly one of the low cost SSD controllers
currently being tested.  The camera will now be tied directly to the
VX855's video capture port.

The network interface will be upgraded to an 88W8686, which will halve
its power dissipation and move it to an SDIO interface (further
dropping the power consumption).   The current goal is to locate it
in a removable module, allowing its replacement for repair.   It will
remain powered while the laptop suspends, waking the laptop if a
packet addressed to it arrives.   It is likely that early production
models will not directly support 802.11s (i.e. forwarding mesh packets
while the interface is asleep), but we are working with Marvell on
several different 802.11s solutions.

Gen 1.5 will continue with the existing display, although OLPC is
working with PixelQi to try to improve the brightness and efficiency
of the screen.   The DCON is retained (even though the VX855 includes
much of its functionality) as it provides the low power interface and
the timing controller functions for the existing display.

Overall, the target is to match the Gen 1 XO-1 in power consumption
while making aggressive suspend easier, and in price (while changing
to components which are more likely to decrease in price).   It is
likely that both goals can be met.

We also expect the Gen 1.5 machines to ship with an OLPC 8.2.x
software release, modified to support Gen 1.5's new hardware but
otherwise unchanged from the current production software release and
compatible with our current software in the field.  Gen 1.5 machines
will be deployed in environments already populated by Gen 1 machines,
so seamless software interoperability is an important goal.

Early versions of the hardware (bare board) should be available for
driver development at the end of May.   A larger number of prototype
laptops (several hundred) for software development and testing will
become available around the end of August.   The OLPC contributors
program will be the preferred way of requesting a Gen 1.5 machine for
testing your software for compatibility or development.  We hope to
use the contributors program to ensure Gen 1.5 support for the wide
variety of application and OS solutions created for Gen 1.0.

We're excited to be finally able to make this news public.  While
members of the technical team have been working on this for several
months, it was not until last week that we could with any certainty
say that we were going to refresh the hardware and what that refresh
was likely to be.  We're now committed to this project and look
forward to working with you to make it happen.

---John, Ed, and the OLPC Tech team.

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[1] http://www.via.com.tw/en/products/processors/c7-m_ulv/
[2] http://www.via.com.tw/en/products/chipsets/v-series/vx855