Re: HTAB won't work!! My strings aren't printing right!! My program isn't working!!!

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

Jonathan Schattke <wizwom@ripco.com> wrote:

> Jon Bettencourt wrote:
> > 
> > Is HTAB supposed to work in 80-column mode?
> 
> I don't have any Trouble with HTAB on an 80 column screen in Applesoft.

HTAB works fine in 80-column mode if you have a IIgs, IIc or enhanced
IIe, except that you can't do HTAB 1.  This is because of the method
used by the 80-column firmware to keep track of the horizontal position.
Memory location 36 (which holds the horiziontal position in 40-column
mode) is set to zero by the 80-column firmware.  Whenever it sees a
nonzero value in this location, the position is copied into the
80-column firmware's horizontal position (a page three screen hole) and
location 36 is set back to zero.

You can't do an HTAB 1 because this sets location 36 to zero, and the
80-column firmware doesn't realise that the program has tried to change
the horizontal position.

If I remember right, the unenhanced IIe has even more problems with
horizontal positioning via HTAB in 80-column mode.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand