an old laptop psu in the range of 11v to 18v
often they will output 3a to 4.5/5amp
however different plug leads both to mains: can be clover, kettle or fig 8 power mains lead
the lead to laptop can vary loads too
a B6 type I THINK uses a 5.5mm power socket
some IBM's Lenovo models use these, others have different plugs and sony's might use a 6.5mm socket plug
You can also opt for a universal laptop psu which has different voltage settings and should come with a number of adapters for different laptops
but ffs check with common sense it all is correct and polarity etc...
some are 19v or 20v which I do not suggest you try
try the shop you bought the charger from - should be able to flogg you one for not much more than a tenner i think