I made small modification to <A href="https://www.thingiverse.com/thing:1831769">Atari SIO plug</A> in order to fit in the FT232RL USB to
...Show more serial board from <A href="https://www.ebay.com/itm/310510484589">ebay</A>. The board dimensions are 26x16mm without pin header. In the Atari plug I used 3.96mm pitch contacts (for <A href="https://www.gme.sk/kontakt-pff04-01ft">example</A>). To wire the PCB you must first desolder the pin header and solder jumper to 5V on the bottom side of the PCB. Then connect:
SIO 3 (Data In) -> TXD (through Schottky diode Atari --|>I-- TXD)
SIO 4 (Ground) -> GND
SIO 5 (Data Out) -> RXD
SIO 7 (CMD) -> CTS
The diode can be omitted if you won't use the adapter in SIO daisy-chain.
You may want to use the transparent filament in order to see the RX/TX activity diodes on the PCB.
