Sorry, I was going by memory before and was a little wrong.
kern310 init=/linuxrc console_level=0 root=/dev/ram0 initrd=smallird.gz vga=769 ramdisk_size=2310 leavepages=6000
The above should be fine. Just save it as whatever name you like. I called it "test". To load I then just use isolinux loadlin @test. (well actually I have it in my autoexec.bat file). This may be different depending on how you have things setup, but should hopefully enough information for you to work it out
Replace kern310 for kernel4 if that's what youre using.
Feel free to ask for help if you need it