Unlike modern home consoles, classic arcade machines were designed for short, quarter-fueled sessions, not long-term saving. However, they did employ several clever methods to handle player progress, primarily focusing on high scores and limited game states.

The most common form of "saving" was the volatile RAM on the game's main PCB. A small battery, often a coin-cell or NiCad pack, was soldered onto the board to provide a trickle of power to this RAM when the machine was off. This allowed crucial data like the top 10 high scores and their initials to persist indefinitely, as long as the battery didn't die. This was the standard for most games from the late 1970s through the 1990s.

Some later arcade systems, particularly SNK's Neo Geo MVS (Multi Video System), introduced a more sophisticated concept: the memory card. Players could insert a personal card into the cabinet to save their progress in extensive games like "Metal Slug" or "The King of Fighters," including their level, score, and continues. They could then resume their game on any other Neo Geo cabinet equipped with a card reader.

For preserving the exact state of a game mid-play (a "save state"), the original hardware offered no solution. This concept is entirely a product of modern emulation. Emulators software that mimics arcade hardware on a PC can take a complete snapshot of the system's memory at any moment and save it to a file. This allows players to save and reload their progress anywhere, a feature never intended by the original designers.

In summary, authentic arcade progress was handled through battery-backed RAM for high scores and proprietary memory cards for game progress. The complex save states we use today are a convenient feature of preservation-based emulation, not the original arcade hardware.