Re: DRAW & XDRAW... How to use

[Pim Blokland <appletalk@at.at>]

In article 
<jonINTERNETrelayCHAT-0501002104030001@nn-157-22-180-14.napanet.net>, 
jonINTERNETrelayCHAT@napaVALLEYnet.CLARInet (Jon Bettencourt) wrote:

> I started the shape table at 31490 ($7B02) and it is 63 bytes long, which
> makes it end at 31552 ($7B40). According to Inside the Apple //e, this is
> in the free space area between HiRes page 2 and Applesoft's string data.

No. Strings eat up ALL available space between STREND and HIMEM 
eventually. Applesoft does not have a built-in protection against the 
strings running into HGR2. The only way you can avoid this is to call 
FRE frequently, or to move STREND (109~110).

> When exactly does
> Applesoft add stuff to the string storage area?

When doing input (INPUT or GET), concatenation (+) and when doing string 
manipulation using LEFT$, RIGHT$, MID$, CHR$ or STR$. Not when doing 
simple assigmnent (like A$ = "whatever" or READ A$); those do not use 
the string space area.

> I _know_ there's no XPLOT. But pretend one moment that there _was_ an
> XPLOT command. Now would XDRAW 0 AT 100,100 act like it? As soon as you
> can answer that, stop pretending.

I'm not pretending, I'm only saying that AFAIK XDRAW 0 is not supposed 
to work.

-- 
Groetjes, Pim

Same excuse every time