HISTSIZE and prompt

["Zhong, Kaixiang" <kzhong@xxxxxxxxxxx>]

Hi:

I am using zsh-3.1.0 on HPUX. 
In .zshrc, I set HISTSIZE to 100, and it does store previous 100
commands.
However, when I type history, it only shows last 16 commands.
Is there any other variables I should set?

Another thing I notices is:
if I set 
1) 'setopt cdablevars ' to enable that the argument of cd can be an env
variable,
2) prompt='%~>'
3) mydir=/home/kzhong/dir/mydir

after I 'cd ~mybin',  my prompt looks like "~mydir>"

but if I change 3) to
3) dir=/home/kzhong/dir/mydir
and after I 'cd ~dir', my prompt looks like "~/dir/mydir" instead of
"~dir".

How can I make it looks like "~dir"?

Thanks in advance.

Kai,

========================================================
  Kai (Kaixiang) Zhong      Phone: (617) 923-6669
  Software Engineer         Fax:   (617) 923-5169
  OneWave, Inc.               or   (617) 923-6565
  1 Arsenal Marketplace,    http://www.onewave.com
  Watertown, MA, 02172      Email: kzhong@xxxxxxxxxxx
========================================================