Bought a Dutch 1040STf with a few mods

[Lastic]

A bit of pretext, I live in Belgium, the neighboring country to the Netherlands and since I know there a lot of Dutch Atari users on this forum also.

I bought an Atari 1040 STf in it's box from a Kringloop shop in Leiden.
It was not New in Box but rather very brown but came with a few nice extras

an ST Documentatie folder from ST stiching Leiden which contains a printed version of ANTIC -Professional GEM
(as found here https://archive.org/details/ProfessionalGEMTimOren )

an Atari 7800 Joystick

a floppy labeled boot which seems to contain some sort of boot selection menu and several utilities ( see attached MSA )

But then under the hood

KAOS TOS 1.4x English version in 6 EPROMS

A floppy boot switch I think ? But it doesn't seem to work with my external Cumana floppy drive
Composite video MOD ? or does anybody have a clue what it's purpose is ?

STFBOOTF.MSA

[Zogging Hell]

A bit of a guess but I presume the video mod is to allow it to work with a standard TV, which the STF, which lacks RF output, would struggle with. KAOS TOS in ROM is a nice find, a pre Magic, Magic

I seem to remember there is something odd with the Cumana drives ID select, can't quite remember what it is though. I also have a STF with a drive switch mod that doesn't seem to do anything.