I'm not sure that you can reasonably demand any width or height of
screen. I don't know how big the Psion hand-held computer is, but the
screen can't be much taller than about 10 lines.
I think it's polite to should make your output adapt to whatever screen
the player is using. For example, the opening screen of "Christminster"
has a short poem and a few lines of title, requiring a 60x22 screen. If
the screen is smaller than this, the poem is dropped and just the title
is printed (this requires a 25x6 screen); if the screen is too small
even for that, then no title is printed and the game starts right away,
though it won't be easy to play. Similarly, "The Magic Toyshop" uses
ASCII graphics to draw the towers of Hanoi (requiring a 43-column
screen):
==|== | |
====|==== | |
======|====== | |
------+--------------+--------------+------
But if the player types "plain", then the towers are described in text
instead:
A wooden board, bearing three pegs.
On the left peg are a big disk, a medium disk and a small disk.
The middle peg is empty.
The right peg is empty.
-- Gareth Rees