PIXEL DRAWER (1K ZX-81)
By Phil Garratt
from Popular Computing Weekly Vol. 1 No. 1 (23 April 1982), page 12

We've tried to keep this program short as possible to allow the maximum memory
space for the actual picture. The cursor is steady when it is drawing, and
flashing when it's not.

Pressing 0 switches from 'plot' to 'don't plot' and back. When the program is
run, you enter the X and Y plotting co-ordinates you want to start from.



NOUGHTS AND CROSSES (16K ZX-81)
By Graham Charlton
from Popular Computing Weekly Vol. 1 No. 1 (23 April 1982), pages 15-16

Here is an elaborate, and extremely hard to beat, version of noughts and
crosses, written for a ZX81 with more than 1K, by Graham Charlton.

You have the option of going first or second in the game. You are the Os, the
ZX81 is the Xs. Wait for the board to change before entering your move which
you do simply by entering the number (o ne to nine) of the square into which
you want to move.

Note how this program makes use of the ZX81's 'string-slicing' ability (for
example, lines 20 to 40).

Play this game in SLOW mode. The program does not say who has won so the game
has to be played out completely.