This is a DATECS DP-50 electronic point-of-sale (POS) cash register/calculator.
It features:
A built-in display for prices and totals
Numeric keypad and quantity controls
PLU keys for programmed products
G1–G4 keys for departments/categories
Receipt-paper compartment/printer at the top
Functions for discounts, percentage calculations, memory, and sales totals
It is designed primarily for retail transactions and issuing printed receipts.