MTX
From CPCWiki - THE Amstrad CPC encyclopedia!
The MTX file format contains all four layers of keys in one file of just 1 KB. This file consist of 128 Bytes File-Header and subsequently four blocks of 80 bytes each. There is ne block for Normal, Shift, Control and Shift + Control. The fourth keyboard layer (Shift + Control) is only available in advanced OS for the CPC. The native OS (firmware) does only provide three layers.
