Re: Applesoft question

[dempson@actrix.gen.nz (David Empson)]

In article <1994Apr20.101806.26404@cobra.uni.edu>,
 <fishern3485@cobra.uni.edu> wrote:
> > [turning off 80-column mode]
> > 
> > On the IIgs (and possibly the IIc - I haven't tried recently), you can
> > also use PR#0.
> 
> PR#0 is a very unreliable way to turn off the 80 col card.

Sorry - I was slightly mistaken.  

All versions of the Apple II Monitor include routines at $FE89 and
$FE93 which set the character input and output hooks to the standard
I/O routines in the monitor (COUT1 and KEYIN).

On the IIgs, calling $FE93 also turns off the 80-column video.  It
doesn't do this on the IIe, and I haven't checked the IIc.

The same effect occurs (IIgs only) if you use PR#0 from BASIC
_provided_ that BASIC.SYSTEM isn't around.  If you try to do this with
BASIC.SYSTEM, then PR#0 has no effect - it leaves the 80-column
firmware active.

> CHR$( 21) works on any 80 col card, all the way back to the first
> ones on the ][+. 

Really?  I can't find any mention of it in the Videx manual I have
here, but I haven't tried it.  The source code listing appears to
ignore it.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand