A: Page 34 of the new manual. It is a CR2032 located near the PCIe x16 slot, partially under the GPU. To reset BIOS, remove battery for 60 seconds OR jumper CLR_CMOS1 (pins 2-3) for 10 seconds.
Happy computing, and don’t throw that old Acer away just yet. acer mg43m motherboard manual new
Use a search engine with site:archive.org "Acer Aspire M3800 Service Guide" A: Page 34 of the new manual
A: No. The new manual explicitly states DDR2 only (400/533/667/800 MHz). Inserting DDR3 will physically not fit (different key notch) and will destroy the DIMM slot. acer mg43m motherboard manual new
Remember: The "new manual" you are looking for is a recently published document. It is the final revision (Rev 2.0) of the Aspire M3800 Service Guide from 2010.