system routines from spectrum 48k for zxbasic.

[funkheld]

hello, good day.

I want to buy "the spectrum" at the age of 76.
I come from Germany.
I'm currently playing with the fuse and the zxbasic.
This zxbasic is wonderful.

I also play with the asm from the zxbasic.
I now want to learn how to use the system routines of the spectrum 48k with the zxbasic-asm.

Where can I find a system listing for the spectrum 48k?

thanks.
Best wishes