how can i back up simple non android gsm mobile phone telephone contacts
Atleast tell which phone you have?
If you have any spare sim, copy contacts to it, wrap it in paper and put it in any safe place(general way applies to all phones.)
Open your contacts menu and try to locate the "export contacts" option. Click on it and choose the option to backup on your sd card. Most probably, the file thus generated will be a vCard file with .vcf extension. Now copy this vCard file onto your computer by connecting through a data cable.
my phone doesnt have any export contact menu-uts a samsung dual sim old model simple gsm