Re: [cc65] Target "BBC"

Ullrich von Bassewitz wrote:
> That's hard to believe, because not only cc65 generated programs, but *all*
> programs would have to live with not knowing their load and start address.
> This would require some sort of relocation, which would be very unusual for
> 6502 machines. How do you load other machine language programs on this
> machine?

As far as I can recall, the BBC "programming model" was that major
applications were sideways ROM images, which all lived at $8000..$BFFF,
and the non-OS/Screen RAM was their data workspace, when they were
running. Once started, these apps did not "return" as such, they would
just start a new application when they finished, or run continuously.

It was possible to load a file at a specific address and run it - the
filing systems had separate load and execution address attributes. These
would typically be set to conservatively high addresses. Relocating
during initialisation was not that uncommon - the non-ROM version of
Acornsoft Lisp did just that, for example (I once had a fun time
adapting the tape version to work on a 6502 2nd processor, so it
could use all the memory available on it).

Stephen
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