What programming model first released in 1991 can be used to write applications for the OPOS API?
OPOS: OPOS, full name OLE for Retail POS, a platform specific implementation of UnifiedPOS, is a point of sale device standard for Microsoft Windows operating systems that was initiated by Microsoft, NCR, Epson, and Fujitsu-ICL and is managed by the Association for Retail Technology Standards.
i don't know