[tech] It beeps!

[Bernard Blackham]

mtearle and I tried burning my new version of the ROM tonight, and
about 7 tries later, we can get it to beep! I moved the beeping code
into the on-boot assembly instead of the C code. I have a suspicion
that the reason it doesn't do much else, is that I can't setup the
stack correctly. I've never had much success in programs that set up
or move the stack reliably.

If anybody wants to checkout the code from CVS and look if I'm doing
anything silly? - reset vector (in vectors.s) goes to _start. _start
does some fiddling of registers, sets up the stack by:
    lds _stack
where _stack is declared in memory.x to be 0x007f - 1 (copied from
another project).

Should this be all that's needed to tell jsr where to put it's
return addresses?

I'll look into it more after exams in 5 days, but if anybody feels
bored in the meantime, there's a starting point.

The next thing I'd like to get working is writing to the display -
this should make debugging *much* easier.

S'all for now.

Bernard.

-- 
 Bernard Blackham <bernard at blackham dot com dot au>