Type-In Listings

Overview

In the 1980s, getting new software meant typing it yourself. Magazines published program listings—pages of BASIC code, sometimes with machine language DATA statements—that readers entered line by line. Hours of typing yielded a working game, and along the way, readers learnt to program.

The experience

The process

Buy magazine with interesting listing
Boot computer to BASIC
Type code exactly as printed
Debug inevitable typos
Save to tape (hopefully working)
Play your creation

Time investment

Program type	Typical lines	Entry time
Simple game	50-100	30-60 min
Full game	500-2000	3-8 hours
Machine code	Hundreds of DATA	2-4 hours

Educational value

Type-ins taught programming by:

Forcing attention to syntax
Demonstrating structure
Encouraging modification
Building debugging skills
Creating ownership of code

Checksum systems

Publications developed error detection:

System	Magazine	Method
MLX	COMPUTE!	Two-byte checksums per line
Proofreader	COMPUTE!	Character-by-character validation
HiSoft BASIC	Your Sinclair	Line checksums

Key publications

Magazine	Platform	Country
COMPUTE!	Multiple	USA
COMPUTE!‘s Gazette	C64/VIC-20	USA
Your Sinclair	Spectrum	UK
Crash	Spectrum	UK
INPUT	Multiple	UK
Usborne books	Multiple	UK

Types of listings

Pure BASIC

Simple programs anyone could understand and modify.

BASIC + DATA

Machine code embedded as DATA statements:

10 FOR I=49152 TO 49200
20 READ A: POKE I,A
30 NEXT I
40 SYS 49152
50 DATA 169,0,162,0,157,0,4...

Hybrid

BASIC framework calling machine code routines for speed.

Machine code challenges

Entering hex data was particularly error-prone:

One wrong number = crash
No obvious debugging
Checksum tools essential
Often split across issues

The culture

Type-ins created community:

Shared experiences at school
Trading modifications
Letters pages with improvements
Reader-submitted programs

Usborne books

Particularly influential series:

Computer Battlegames
Computer Spacegames
Write Your Own Adventure Programs
Clear explanations alongside code
Now freely available online

Decline

Type-ins faded as:

Cover tapes/disks became standard
Programs grew too complex
Commercial software improved
Internet distribution emerged

Legacy

Type-ins established:

Programming as accessible hobby
Learning through doing
Magazine-reader relationship
Foundation for bedroom coders

Games you had to earn