That's an old model these days. I used to have notes for it but they were lost years ago. You need to run through the status clear in the manual. That stops any program lock ups and returns to REG mode. I can only find one on the net:
http://the-checkout-tech.com/manuals/cashregisters/TEC_MA-1450-1_programming_manual.html
Hope this helps
Registerman
October 2013