Calling Applesoft GR routines from assembler

I used to have a document, magazine or book (well, I may still ahve it somewhere but I don't remember) back in the day which had info on how to call the Applesoft GR and HGR routines from assembler.  Basically where to JSR to do things and what memory locations and registers to set first.

If anyone has that or can point me to it, it would be great.  I wrote a little Applesoft program that draws a splash screen in low-res for a 32MB ProDOS disk image that I'd like to convert to assembler and make a .SYSTEM file out of.

It should be super simple and it will be an excuse to assemble something with the 65C02 cross assembler that I wrote a few years ago.