Low-cost ARM or MIPS all-in-one computer for office use & home use (design)

Low-cost ARM or MIPS all-in-one computer for office use & home use

This kind computer use public version of the PCB board designing scheme. And the shell use public mold scheme. So can greatly reduce the cost.

More detailed about the main chip (Soc chip) of this kind computer, please visit:
http://jmskl.blogspot.com/2013/12/chipset-for-low-grade-tabletpcset-top.html

CPU: ARM Cortex-A7 1.3Ghz Quad core, Cortex-A9 1.5Ghz Dual core, Cortex-A9 1.5Ghz Single core etc.
RAM: 1GB, 1.5GB or 2GB DDR3 RAM
Storage: 4G eMMC
Built-in WIFI: IEEE802.11 a/b/g/n 150Mbps max. 2.4Ghz & 5Ghz double frequency
Front camera: optional
12 inch LCD screen, LED backlight, 1024x768 resolution
(Also have some other size of LCD screen)

Pre-installed operating system: a Linux release edition (Linux mint, Ubuntu, Debian etc.) & Android (4.4.4 or 5.x or 6.0)
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The back head of the all-in-one computer

Ports in the prominent part of the back head:

Ports in left (or right) of the prominent part of the back head:

Schematic diagrams:
When the computer start up, show a boot menu, user can choose one operating system to enter:

When running Android:

When running Linux:

Another schematic diagram: