CBASE [(#ch)](Btool) and
The function CBASE finds the start address of the channel definition block which belongs to #ch. This is an area in memory where QDOS stores a lot of information about the channel, for example, which kind of device is connected to the channel.
The Btool variant returns the base of channel #1 if #ch is not specified.
The Pointer Interface modifies the structure of channel definition blocks for windows.
You can also use the CHAN_ <KeywordsC.clean.html#chan_>xx functions to look at the channel definition block.