Bus and Tag

[3] Bus and Tag cables are "daisy chained"; and one interface can attach up to eight peripheral control units.

It was later published by the US National Technical Information Service (NTIS) as FIPS PUB 60-2, I/O Channel Interface.

"[4] Equipment is available to allow connection of older devices using Bus and Tag to mainframe FICON[8] or ESCON channels.

As DASD became faster, the original channel protocols could not support the required transfer rates and the two-byte interface was too expensive.

The following schematic shows a complex system with two CPUs and multiple peripherals connected using bus and tag cabling.