I have just bought one of the rare kh810 brother machines that was produced with both the preceding 8 push button system and the 'new' card reader to control patterning. No other model manuals work for it for this reason, I need info on how you can (and can't) use both systems simultaneously.
There are no manuals in the public domain so reaching out to see if anyone has one in their stash they could copy and send? Be great to also see a copy added to the other brother manuals on machineknittingetc so that other 810 owners can access it too....
I had a Toyota KS787 many years ago. That has a similar patterning system. You could add extra patterning to the punchcard designs by using the buttons.
Hope you can find out how yours works.
I would worry first about mastering each process....then the combinations might occur to you....but this was not the main thought behind the machine....it was to give you both options.... search the net for your manual...most are free to download.