Hi Pat. There are codes that you need to use to select the products and edit the prices. there is only one place I know of to get the programming information for these now:
https://the-checkout-tech.com/manuals/cashregisters/Towa_ET-7626_and_MR1_programming_manual.html
Don't worry about the different model number. they were re-branded for the UK market.
You need to use the PLU programming section.
Hope this helps
Registerman, January 2015