the tentative charger chip will allow not only running from "AC" but even booting the device without battery - from both Nokia system 1) and Apple system 2) USB chargers. However what's probably not working resp could cause the whole device to reboot hard is GSM transmission at the higher power levels (adjusted by BTS according to roughly your distance from BTS). Since the modem can use up to several Ampere bursts of current, it will need a buffer battery or at least TX will fail. The CPU *should* 'survive' such short brownout of power supply, but I cannot guarantee that yet. Buzzword hotswap which is based on such CPU buffering during short brownouts.
Internal uSD in parallel to the existing uSD and to the planned eMMC is hardly feasible, we would need to multiplex that, and also the assumtion of it "needing almost no space" is not exactly correct. Also theoretically eMMC is twice as fast as uSD, thanks to doubled data bus width.
On the bright side, eMMC should have a rather long life span, and it's not the most complicated part to replace, actually swapping that chip is one of the simpler tasks.

1) D+/D- short
2) resistor voltage-dividers on borth D+ and D-

here's crossing fingers the tentative charging chip becomes "the fur shure chargin' chip"

Tried to donate 3 times in the early days but was not allowed because I didn't have a post code. Gave up and spent the money elsewhere. I just want a faster n900. Love it to bits. Now there's a paypal option I'll save up and donate again. Nice to know there's another 1972 model out there. Keep it it up, I appreciate what you lads are doing and would love to own a neo900.

NOTICE
Risk part: camera switch
http://industrial.panasonic.com/www-...TK0000CE24.pdf gets discontinued
Pondering amount to secure, resp alternatives to securing a certain amount right away.

This is just an info to let you know what's going on and prepare you for times when we run into more of this sort of issue. Also it shows how "preorder window" may eventually close suddenly. This particular issue is not considered any sort of problem yet.

cheers
jOERG

And if I don't preorder, will it be possible to get a Neo900 when it's sure the device will surely be produced?

We cannot guarantee that, since - see above. when we for (made-up) example get a 500 camrea switches now, then we will be able to sell only 450 devices later on, since the switches will not be available anymore. Again this is a made-up example to explain the situation we might face, ideally the amount of devices we can build is unlimted, but don't hope for that, since it may - and probably will - change eventually. We need to secure/source components and the count of components we secured will determine the size of first batch to build. For a possible second batch we again need to reach a certain minimum count of preorders and then start to see if we can find another maybe 300 (or whatever the preorder count) $whatever-all-the-components-needed (camswitches, RAM chips, etc pp). You generally cannot source an additional 10 or 50 of any such component. You buy one "huge" batch and you hope that "huge" batch is just large enough to meet the minimum order quantity of each component, which often is a 1000 or even 2500.
Hope that shed some light on the situation.
cheers
jOERG

There's always the option to disassemble the battery and swap the cell to a new one that roughly fits (not physically larger dimensions than original one).

Neo900 resp actually the NeoN bare board will even support custom made batteries that have a BQ27000 embedded battery gas gauge chip (identical to the BQ27200 used in N900, and Neo900) connected to the BSI contact. You could probably accomplish that by using the electronics PCB of a GTA02 smart battery and marry it with the "case", contact claws, and cell of a BL-5J. (though the GTA02 smartbatt is a tad thicker, so it might fit or not)

And what if a neo breaks after the warranty period. I won't be fixable because of the lack of spare parts.

That's why I said "500 cam switches means we can sell 450 devices": 10% for replacements. Don't worry! :-)

And what if a spare part breaks in 60 devices? The modern devices are very prone to hw damage.