Retrobit – Kartridże, akcesoria i płytki do Commodore 64, ZX Spectrum, Atari | Polska produkcja
PCB Extender Board for Atari 1200XL
This board simply extends the internal cartridge connector slightly, allowing certain cartridges to now be connected to the 1200XL model.
It contains no active or even passive components. Literally, it is just an edge connector soldered to a printed circuit board.
https://www.pcbway.com/project/shareproject/Atari_1200XL_Extender_Cart_b7bbd0f9.html