Reddit mentions of Casio MS-80B Standard Function Desktop Calculator,Black

In no particular order:

• Poker chips, one set for smaller games (pictures from before I converted to gray 20s), another set for larger games. For more details on poker chip choice, see this thread.
  
• Cheap plastic poker chip trays for away games. Or nicer custom-made ones for home games.
  
• Priority deal marker.
  
• Large button solar calculators for everyone. (I like/use these) Also pencil and paper for everyone.
  
• Perspex/acrylic sheet to place over paper maps.
  
• Plastic tubs to replace game boxes.
  
• Pencil and paper for end-game paper spreadsheets.
  
• Lemmi's moderator.
  
• Heavy lumps (in this case of brass and stainless steel) to hold down light-weight maps.
  
• Portable halogen lights for playing games at poorly lit conventions. (We had two parallel games of 18C2C there)
  
• Track-tile trays. (These trays work well -- just cut the hinges to remove the lids. The compartments are large enough to hold larger numbers of tiles without slopping over and you can then hold the lids on for storage between games using a band or tie)

>People still use desk calculators?? :)

They sure do. Here are two of the best selling calculators of any kind:

https://www.amazon.com/dp/B003822IRA/

https://www.amazon.com/dp/B000I3C4EY/