Re: [cc65] Target "BBC"

From: Stephen Thomas <>
Date: 2005-03-30 23:04:03
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).

To unsubscribe from the list send mail to with
the string "unsubscribe cc65" in the body(!) of the mail.
Received on Wed Mar 30 23:01:59 2005

This archive was generated by hypermail 2.1.8 : 2005-03-30 23:02:05 CEST