Re: New Apple II blog

[JJ Sonick <jj.lawrence@gmail.com>]

On Oct 22, 9:26 pm, heuser.mar...@freenet.de wrote:
> On Oct 22, 9:09 pm, JJ Sonick <jj.lawre...@gmail.com> wrote:
> > Oh, and I forgot to say: comments very much welcome here and
> > on the blog!
>
> Your first few entries make up for an interesting read!

Thanks!

> While learning assembly I found it best to NOT rely too much in typing
> in printed example programs. You not only may find errors but they
> also tend to be rather extensive for what they do - and often you don't
> have a real need for these programs or routines. Short assembly programs
> can be as demonstrative and don't take too much of your time.

Hm, OK, I may indeed avoid the more mammoth listings.

> If the book you currently use doesn't handle hi-res graphics very well
> you should look for another one (there are enough out there).
> A good read for the budding Apple II graphics programmer is the book
> "Graphically Speaking" by Mark Pelczarski (co-programmed "The
> Graphics Magician" which was the basis for many graphics adventures)
> which not only describes the workings of the hi-res mode but
> introduces you to use assembly with this mode, using simple examples at first
> which slowly get more elaborate in later chapters.

The "Assembly Language for the Applesoft Programmer" book does have a
decent-looking chapter on hi-res graphics followed by a chapter
covering a simplistic arcade game, but the "Graphically Speaking" book
definitely sounds worth seeking out - thanks! (Speaking of the
Graphics Magician, at some point I plan to do a post comparing it to
Synergistic's Game Animation Package).

> I can't help you much with sound routines

I do have some leads there, I have a couple of books that include
assembly sound routines, so I'll be exploring and tweaking those (the
very simple one in the current book I'm reading looks like an
excellent place to start).

>but your goal #2 (tile-based
> graphics scrolling) is similar to a goal I had three years ago (damn,
> you time flies!): A fast enough routine for the Apple hi-res screen.
> And yes, "quirky" is a word often attached to the Apple screen modes
> because of their funny memory locations and bitmap interpretation.
> The hi-res mode also is quite powerful which games like Ultima
> exploited
> very well: Six colors including a hi-res white while other systems had
> their own constraints or needed bigger screen buffers etc.
>
> There are lots of possible solutions for this problem but it
> ultimately (bad pun!) comes down to a memory copy routine - which, obviously,
> copies bytes from the tile memory area to the screen buffer.
> Of course it's up to the game design how complicated it will be but
> for a space RPG where you don't want to restrict the field of vision like
> in Ultima IV it may be rather simple.
>
> I can supply you with an example of a really fast routine but you
> should be able to handle it as it needs an infrastructure to operate
> - your call, really.
>

That'd be great!  Even if it takes me awhile to get a full handle on
it, it'd be excellent to have an example. If you want to send it via
email, the best address to send to is jjsonick at yahoo dot com.  Much
thanks!

Josh