OK, so each rom has a digital serial number and will only run on that person's AtariMax...or a particular emulator.
Do you want to know why this is a stupid idea???
1.) If you have an AtariMax, each person would have to have their own firmware update with their own unique serial number...and that would also mean that every rom that person has from multiple publishers would have to have the same serial number or you would be dealing with multiple firmware updates to play different games from different publishers.
2.) Playing on an emulator...same problem as above except compounded by the fact there are multiple ColecoVision and ADAM emulators. I don't always use the same emulator to play games with. So again you are faced with having multiple emulators with multiple serial numbers coded into them from multiple publishers for multiple games.
Do you really think anyone wants to deal with that headache?
With a firmware update to the ATARIMAX cartridges a digital serial number could be assigned to each cartridge. Then when someone purchases a copywrited rom image online, that rom image would only run on that persons Ultimate SD cartridge since the serial numbers would need to match up. The same serial number checking technique could be created for ColecoVision/ADAM emulators for PC’s and portable devices.
Some game developers are afraid to spend months or years making a great game, only to find out that someone posted the rom image online for 1,000+ people to download for free. Having some type of serial number checking process would prevent the rom image from loading on unauthorized devices. I know this is not as good as unbreakable 256 bit encryption, however this would prevent most people from pirating the videogame since only a knowledgeable programmer would know where to edit the rom image to remove the digital serial number copy protection technique.