How to play

You play the white checkers against Gnubby, from the bottom right round to the top. Click the screen, then use your keyboard: the game reads the Spectrum's keys, and the arrow keys are the Spectrum's cursor keys. On a phone or tablet, tap the keys under the screen: they are the ones the game will take at that moment.

M, 1, 3, 5, 7

on the title: a money game, or a match to that many points

R

roll the dice

D

double (before you roll), or swap your dice while you move

Q / A, ↑ / ↓

the cursor up towards your 24 point, down towards your 1

Space

move a checker from the cursor's point by the next die

1, 2

move it by that die

Enter

finish your move

U

undo the move so far

H

let Gnubby show you his move

I

show or hide the pip counts

Y, N

take or pass a double; play again or not

Only legal moves are accepted, and you must use as much of your roll as you can. Gnubby takes about seven seconds to choose a move, and in a close position as long as twenty to weigh the cube, as he would on a real Spectrum: Speed runs the machine four times as fast.

When a game is over, Save the games (or, once a match is over, Save the match) under the screen gives you the games as a .mat file, which GNU Backgammon and other backgammon programs can read, to replay or analyse.

On a real Spectrum or another emulator, load zxgammon.tap with LOAD "", or open the snapshot zxgammon.sna.