The Ateobus was designed by Ateo for use with their tower systems. The Ateobus is really just a customised ISA bus with some slight modifications and has a maximum speed of about 9.3MB/sec. There is no support of ISA DMA however it does have a "fast" mode for cards like the Pixel 64. This bus could in theory use ISA cards which do not require DMA, however the drivers were not open and only ever written by Ateo themselves. The bus comes in two sections. The first section plugs into the trapdoor slot of the A1200 and includes a pass-thru for accelerators whilst the other section is the actual bus.

Thanks to Olivier Croquette and Jaeson Koszarsky