Re: A86: Fonts


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Re: A86: Fonts



DEATH wrote:

> in:
>         ld a,0          ; set up font pointer (it's 24-bit)
>         ld ($D2ED),a
>         ld hl,Font
>         ld ($D2EE),hl

The pointer is not 24 bit, it's a 16 bit word + a RAM block byte.
If the block byte (or whatever it's called) is 0, the pointer
points somewhere to RAM page 0 ($C000-$FFFF). If it's 1 the RAM
pointer is $0000-$FFFF, divided into the RAM pages 1-4, and if
it's 2, the pointer is $0000-$BFFF (RAM pages 5-7). At least
that's how the VAT works (and it's reasonable to assume it works
the same way in the whole ROM). The first variables (xstat) is
stored at $01 $4000, ie the beginning of RAM page 2. (I've done
some research about the VAT and how the access external variables
with ROM routines).

-- 
Jimmy Mårdell                   "We are the crown of creation
mailto:mja@algonet.se            we may do whatever we please
http://www.algonet.se/~mja       Fuck nature, man rules!"
IRC: Yarin                         Fuck Nature /Cat rapes dog


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