The Bubble System is an arcade system board designed by Konami and used across many arcade games in the early eighties.
The Bubble System was supposed to have a unique new form of data storage for arcade-style video games. It used bubble memory cartridges, a sort of non-mechanical magnetic storage system. It was said to have a higher reliability than mechanical diskette or tape drives.
Konami used their new G400 BIOS for this project, and modified it a bit. The main CPU was a Motorola 68000 at 10 MHz. There was a separate Zilog Z80 for sound control, which drove two AY-3-8910s, a custom Konami SCC (K005289), and a VLM5030 speech synthesizer. It had a Scramble wiring harness.
A Bubble Memory game can be identified by its booting sequence. It displays a "warming up" screen, accompanied with a countdown timer and a small musical tune (called "Morning Music"). The reason this was implemented was because Bubble Memory had to be heated to around 40-50°C for it to work properly.
Bubble Memory was not a fully developed technology by the time it was used in the Bubble System, and as a result it is currently very rare to find a working Bubble System. The system proved to be unpopular because it had a high sensitivity to magnetic fields (which was not suitable for an arcade environment, with unshielded speakers and degauss coils), and were also considerably more expensive than ROM chip-based boards. Most games on this system were eventually ported to standard ROM chips, and the system was discontinued.
Still, Konami has made homages to the Bubble System in 2 recent games; with Morning Music being one of the playable tracks in Keyboardmania.[1], and the intro of Konami Classics Series: Arcade Hits featuring the song too.