BTest-2 Release Notes
The Meaning of BTest-2
There is typically one or two builds of systems internally before an external beta test, so our BTest-2 is really beta test for the electronics, while beta test for the new screen, touch pad, industrial design, and keyboard; this is earlier in the development cycle than systems are usually made available, and is correspondingly rougher. This is the beta test of completed electronics, as the Altera FPGA used for CaFE has been replaced by a functional ASIC. The camera, SD slot and NAND flash are interfaced via CaFE; the ASIC version is in BTest-2 and has significantly higher performance for both SD and NAND flash, and uses significantly less power.
Hardware Specification
The BTest-1 systems were built with an extra 128meg of RAM, to partially make up for well known memory problems in key applications, in particular the web browser, based on Firefox's Gecko technology. Work is well underway to reduce the browser's footprint; some of this work is visible in Firefox 2.0 and is now in the latest Sugar builds (post build 239). BTest-2 was built with 128 meg of RAM total; this is necessary so that we can qualify the multiple sources of RAM in working systems for high volume production.
Note that we are also testing an alternate battery chemistry from NiMH; a lithium based battery chemistry has become available that has none of the safety or environmental problems of Lithium Ion, is less costly than NiMH (Nickel prices have gone through the roof in the last year), and can charge at much higher temperatures, important for use in some parts of the world which can be so hot as to exceed the temperature at which NiMH can be charged. These batteries can be identified by large labels "Battery Sample" on the battery packs.
The hardware specification is elsewhere in the wiki.
Hardware Release Notes
Our master list of hardware and mechanical issues and status can be found in the trac system we use. Please check this list before entering new issues: but please do enter issues you discover. The items below are the most significant from the list.
- Hardware performance is not what it will be
- The B-Test systems run 33% slower when USB networking is in use -- the internal wireless device is connected over USB, so triggers this problem. We suspect a fix for this to surface in the next few weeks.
- The battery charging algorithms have problems
- The old EC code shipped with some units had a bug which prevented startup with low battery and another bug which prevented charging with a low battery, and also high power usage by the EC, which would drain a battery if left unplugged in a matter of a day or two. Updating to EC Q2B61 should fix most battery charging problems and please report any further difficulties. Please read this bug report for more information. BTest-2 should also be able to "resurrect" batteries that are so discharged that they cannot even be sensed when put into a system by a new trickle charger circuit.
- Inconsistent battery charge state indications
- The EC can't report proper charging or capacity information and is overly conservative on the amount of power remaining, as the hardware chosen for the battery pack to report capacity is incorrect; this should be fixed in the BTest-3 build.
- Keyboard keys occasionally stop working, and sometimes the machine does not reboot.
- (ESD problem with the embedded controller.) One of the most irritating and noticeable problems is a static discharge problem that can lockup pins or entirely crash the embedded controller, causing some or all of the keyboard keys or touch pad to stop functioning (requiring removing the battery for a period to allow the EC to reset fully). We believe this has been fixed in BTest-2. We will therefore be very interested if anyone sees this problem in BTest-2.
- Power management is as yet unimplemented
- Therefore you cannot suspend and resume the machine (yet). The preparatory work in the firmware is complete, though not yet deployed, so this becomes very high priorty to us.
- The internal microphone
- is still mispositioned in BTest-2 (too close to the speaker), and build 239 does not have the codec properly configured to avoid feedback.
- Touchpads are too "noisy"
- this is being mitigated with the addition of a Mylar sheet on top of each touchpad. The Mylar sheets improve touchpad performance for B-Test 1 machiness too. You can also recalibrate the touchpad, by touching all four corners of it at the same time. The Mylar sheet looks like a plastic sheet -- you should not remove it, else touchpad accuracy will decrease.
- SD high-speed not working yet
- We now do support high-speed SD, but are not seeing very high transfer rates when in high-speed mode yet.
Fixed since BTest-1
- The resistive sensor does not work
- (for use with a stylus for writing), due to a design flaw: This is fixed on BTest-2 systems.
- The arrow keys ("game keys") cannot be distinguished from the arrow keys on the keyboard
- This is fixed on BTest-2 systems.
- The screen is covered by a plastic film by mistake
- This was resolved in BTest-2, and a diffuser coating significantly improves the screen quality.
- Manufacturing data values are in the wrong order
- This is fixed in BTest-2 (and when BTest-1 systems' firmware is first upgraded).
Design Release Notes
The BTest-2 systems do not have textured plastic: this is intended for future builds.
- Other design issues are also under investigation
- Note that design is always an over constrained problem: it is often not possible to get every thing you would like in a design, though you can usually get most or all of what you value most.
Software Release Notes
There is a separate page for Software Release Notes.