Konami · 1985 · 1985 – 1986
CPU: Motorola 68000 @ 10 MHz + Zilog Z80 (sound)
Konami's swappable-game arcade board stored its software on magnetic bubble memory — which had to warm up before it would work. It launched Gradius and TwinBee, and then every game on it was moved to ordinary ROMs.
Konami announced the Bubble System in January 1985 as a way for arcade operators to change games cheaply: the main board stayed in the cabinet and the game arrived on a cartridge of magnetic bubble memory, a non-volatile storage technology that was briefly fashionable in the early 1980s. The board itself was a capable 16-bit design, with a Motorola 68000 at 10 MHz as the main CPU and a Zilog Z80 handling sound. Bubble memory brought two problems. It only worked reliably at around 30 to 40 °C, so the cartridge had to be heated before use, and because the memory could not be executed directly, the whole game had to be copied into RAM before it could start. Operators switching a machine on were greeted by a countdown while the hardware warmed up and loaded. The cartridges were also considerably more expensive than ROM chips and extremely sensitive to electromagnetic fields, which could corrupt the stored game and leave it unplayable. The system still hosted significant releases. Gradius debuted on it in 1985 — appearing outside Japan on a standard ROM board as Nemesis — alongside TwinBee, Galactic Warriors and the racing game RF2, later converted to ROM as Konami GT. The Bubble System was a commercial failure, Konami moved all of its games to conventional ROM boards and discontinued it, and working cartridges are now rare collector's items.