UTILITAIRE -> Outils pour disquettes et cassettes   

I have seen many times this kind of code in the past. Essentially, the values in each line starting with DATA represent bytes.
There are 8 values (representing 8bytes) and the last nineth value is the sum of those, used for finding errors.

Each byte is "POKED" into memory, one after the other, starting at the position 0x4000.
That's really all there is to it.
Afterwards the machine code subroutine is called, by issuing CALL &4000 and then an RSX command is at your disposal, by issuing |QF,"V"
V is a single character that can be either 'D' -> for Amstrad's data format and 'V' for Vendor format.

e.g. |QF,"V" will start a (quick)format on the drive A using the "Vendor" or system format. This is suitable for use with the CPM operating system.
For normal usage with Amstrad's locomotive basic you'd use |QF,"D" instead.

Paru sous forme de listing dans le magazine Amstrad Action Issue 73, October 1991
Auteur : Adrian FORBES