Header, female, 1 x 40 pin, straight

*Part number*	*Datasheet*
Farnell: 1667503	Samtec, BCS-140-L-S-TE
Mouser: 200-BCS140LSTE	Samtec, BCS-140-L-S-TE
RS: 766-6593	Samtec, BCS-140-L-S-TE

This component is very expensive from popular suppliers.

Homebrew 8-bit retro computing