NTSC/PAL/SECAM & PERITEL?
If you do not know what these acronyms refer to, please read the "NTSC/PAL/SECAM/PERITEL" article in the knowledge base first.
The computer
The documents and hardware I own don't give me any clue about the official release date of this PERITEL Atari 400 computer in France, but I'll assume it was released alongside its sibling, the PERITEL Atari 800, in September 1982.
To read about the PERITEL adaptor and the resulting video output, I invite you to read the PERITEL Atari 800 article first. In this article describing the 400 model, I will not duplicate information found elsewhere on this site. The PERITEL Atari 400 is also a mod of a PAL Atari computer, with a daughterboard-card.
Remark: the antenna cord was removed on this one but it is usually there and continues to work. See the family pictures (below) with the other ones, the antenna cable is still there.
3 computers
I am the happy owner of 3 of these machines too...
Inside the machine
The PERITEL adaptor daughterboard-card
The RGB signal from this PERITEL adaptor
PEEK identification
Using "PEEK" instructions in BASIC to find out about the OS, Basic and NTSC/PAL versions.
For your information, the results are:
PEEK(53268) = 1 [PAL/SECAM]
PEEK(65528) = 214 [400/800 OS Rev. A/PAL, 1979-06 (common)]
PEEK(65527) = 255 [Not a XL/XE]
PEEK(43234) = 162 [Atari BASIC Rev. A, in external cartridge]