You can't use more than 38911 for code.
You should be able to use c000 for variables, but that can't be in addition to anything in the 38911 area.
Luckily for me, all my programs are composed of code
and data. The data arrays works perfectly in the area above 38911.
All that rest can only be accessed with POKE and PEEK, which is a tad boring to code.
It is exactly like coding in asm. Which is fine.
I ran out of ram in a basic program once and then I stopped writing basic programs.
I ran out of ram all the time. I wrote large programs. But then I discovered a basic compiler (which I think was called Blitz64 but I can't really remember) which squished the size of my code down enough that my programs could just barely run. It stripped away all the REM statements to save a lot of space.
Luckily the Amiga came out and saved me from ?OUT OF MEMORY ERROR IN LINE 12756 for many years until I started getting out of memory errors on my 32MB Apollo 060.