Re: Recommend some documentation

[sicklittlemonkey <nick.westgate@gmail.com>]

On Feb 20, 1:35 pm, Steve Nickolas
<lyricalnan...@usotsuki.hoshinet.org> wrote:
> On Sat, 19 Feb 2011, Payton Byrd wrote:
> > On Feb 19, 12:53 pm, Steve Nickolas
> > <lyricalnan...@usotsuki.hoshinet.org> wrote:
> >> On Sat, 19 Feb 2011, Payton Byrd wrote:
> >>> I just spent some time googling how to change the screen memory that
> >>> the 80-column text display is pointing at and didn't find anything
> >>> relevant.  Can anyone recommend a good book or other documentation
> >>> relating to the programming of 80-column text mode?
>
> >> There's only two places it can point: page 1 (0/0400-07FF and 1/0400-07FF)
> >> and page 2 (0/0800-0BFF and 1/0800-0BFF).  I'm not even sure if page 2
> >> works with 80-column mode.
>
> >> -uso.
>
> > What register do you set to switch between the two?
>
> Hit C054 (lda/bit) to enable page 1, C055 to enable page 2.  This at least
> works for the old ][-compatible text and graphics modes; I do not know if
> it also applies to the //e's modes.
>
> -uso.

The function of C054/C055 changes depending on the setting of the
80STORE softswitch, which the built-in 80-column firmware uses. You
should have a read of the //e (standard or technical) reference
manual:
http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Computers/Apple%20IIe/Manuals/

Cheers,
Nick.