Here is a list of what's new in version 4.21f:
● support for contactless Discover Zip cards
● support for Partial Approval transactions with pre-paid credit cards
● Balance Inquiry on pre-paid credit cards
● Pre-authorization with Loyalty transactions
● Surcharge on Debit Transactions (with configurable limits)
● Enhanced Terminal Security via Manager Passwords
● new hotkey combination for terminal language setting
● readability improvements to Sequence # on receipts