My custom PPD to make Samsung ML-1860/1865 printer work with SpliX. Tested and working on Raspberry Pi.
Manual duplex is working as intended. A4 is the default paper size.
Make sure you have SpliX installed on your system, e.g.
sudo apt-get install printer-driver-splix
Go to CUPS admin page (somehost:631) and select this PPD for the printer.
GPLv2