"Grand Thieves & Tomb Raiders - How British Video Games Conquered the World", by Magnus Anderson & Rebecca Levene, contains a copy of a type-in listing for the ZX Spectrum game Snake.
It was originally submitted in 1983 by David Perry, of Earthworm Jim fame, for the magazine "49 Explosive Games for the ZX Spectrum", written by Tim Hartnell.
This was a time when games were loaded onto the console by typing the code line by line.
If you would like to experience this for yourself, you can download Fuse, a free ZX Spectrum emulator, and type in the listing below.
There are a few basic rules you need to follow for entering the code on the emulator.
The listing makes use of special keywords such as "PRINT" and "LET". Rather than typing these letter by letter, you need to use the commands for these which are dotted around the keyboard.
First of all, open the keyboard by clicking "Help > keyboard".
Then enter the commands by doing the following:
The type-in listing has been reproduced below, with corrections for mistakes found in the "Grand Thieves & Tomb Raiders" copy.