Complex sentence: These codes were basically modeless, although triggered by the the resulting "escape mode" automatically exited again when the command was complete, and they could be interspersed with display text anywhere in the stream of data.
Split into simpler sentences: These codes were basically modeless; triggered by the the resulting "escape mode" automatically exited again when the command was complete. Escape codes could be interspersed with display text anywhere in the stream of data.