The are two versions of Locomotive BASIC used in the Amstrad CPC and CPC+ computers. v1.0 is used by the CPC464, and v1.1 is used by the CPC664, CPC6128, CPC464+ and CPC6128+.
== BASIC v1.0 only ==
There is a region of memory between AC00-AC1B which is filled with RET instructions. The BASIC ROM calls the following locations:
AC01,AC04,AC07,AC0A,AC0D,AC10,AC13,AC16,AC19
It almost looks like these were used for debugging the ROM but were left in.
They can be used to implement new BASIC commands.
== Passing parameters to a RSX (Resident System Extension) command or binary function ==