Yes indeed Martha. I'll set you as a contact (I think that will work) as I'm sure our paths will have commonalities that will interest us both. I've yet to update my profile with info that has more details than those included in my introduction post. The template for notching the film holders is interesting. As a computer programmer from many decade ago, a binary solution was an obvious choice. However, I'm keen to see your solution. I don't need to go far to get the code system drilled. . . . my husband is a retired carpenter.