Computers and Laptops
Blue Bins & Chutes
If it is still working give it to an organisation that can pass it on to one of their beneficiaries. Someone in need may appreciate being able to use your old computer.
Bridge The Digital Divide
Metta Welfare Association
Freecycle / Give Away
Likewise there are thrift shops that take donations of working laptops and tablets to raise funds for their organisation.
Put in the e-Waste bin. However note that there is a size constraint: devices must be able to fit through a 500mm x 250mm slot.
If your e-waste is too large to fit in the eBin, you can wait for the next eDrive happening near you.
3-in-1 e-Waste Bins
E-Waste Collection Events (E-Drives)
eWaste tends to have good resale value so Karung Guni are usually happy to take it.