XO 1.75 C2
The C2 version is the XO-1.75 entering production. Electrically, these are almost identical to the C1 prototypes and very similar to the B1 prototypes. XO-1.75 production ramped at the beginning of February, 2012.
XO-1.75 laptops have seven small raised dots on the hinge cover, arranged in two rows. XO-1 laptops have a smooth hinge cover, and XO-1.5 laptops have three small raised dots inline on each side of the hinge cover. Open Firmware cpu-model OLPC 1C2
- There is a single large chip (the Marvell Armada 610 System on Chip) instead of two large chips (the CPU and a companion chip used in XO-1/1.5).
- The motherboard revision is F
Two version of C2 were built (SKUs 203 and 204), testing out various alternate component suppliers. From a software and functionality point of view, however, these should be identical. They differ in the amount of NAND Flash and SDRAM provided (8GB/1GB vs. 4GB/512MB), as well as the keyboard (traditional or our improved membrane).
If you disassemble the laptop (instructions), you will see:
See XO-1.75 software.
See http://dev.laptop.org/1.75 for tickets that are not closed, in the XO-1.75 firmware or software milestones.
Increased power draw in suspend
SKU 203 laptops have a motherboard which doesn't have the additional circuitry needed to reach the lowest power when suspended. They will draw approx. 150 mW more than SKU 204 laptops in suspend.
All further production will use the lowest power BOM used in SKU204.
Supporting documentation for this laptop (all in PDF):
- Detailed Specifications
- Connector Locations
- GPIO Mappings
- Motherboard schematics
- Power Distribution ( PDF )
- EC Pinout
- Component locations (old): bottom, top
- Unbricking using CForth and using JTAG. JTAG interface on XO-1.75.
- eMMC/DDR3 Components
- Motherboard photos
- Power Measurements
- Safety and RF Certifications