How Do Dell Laser Printer Toner Cartridge Chips Track Page Counts and Block Refills?

I'd like to put my limited electronics knowledge to good use but have struggled to think of a worthwhile project. After building an ECG using an microcontroller and a handful of components I ran out of original ideas. I'd like to understand the technology used in toner cartridge chips which stops them working after so many pages. I have a pretty good Dell laser printer which didnt cost very much.Of course the cartridges are ridiculously expensive. I buy in chips from China and refill the cartridges saving 80% of cost of replacement cartridge. I'd like to know how the chips work and I'd like to make my own chips also. Can anyone give me a steer in the right direction ? If they can do it in China.......

Hi Gregory,

There are several concept on how the printer prints but the most common of it is done by simple chip manipulation.

same with this video here -> https://www.youtube.com/watch?v=IHnXLpdUO-o

God Bless.

Best,
Neil