A type-in program or type-in listing was computer source code printed in a home computer magazine or book. It was meant to be entered via the keyboard by the reader and then saved to cassette tape or floppy disk. The result was a usable game, utility, or application program. Type-in programs were common in the home computer era from the late 1970s through the early 1990s, when the RAM of 8-bit systems was measured in kilobytes and most computer owners did not have access to networks such as bulletin board systems. Magazines such as Softalk, Compute!, ANALOG Computing, and Ahoy! dedicated much of each issue to type-in programs. The magazines could contain multiple games or other programs for a fraction of the cost of purchasing commercial software on removable media, but the user had to spend up to several hours typing each one in. Most listings were either in a system-specific BASIC dialect or machine code. Machine code programs were long lists of decimal or hexadecimal numbers, often in the form of DATA statements in BASIC. Most magazines had error checking software to make sure a program was typed correctly. Type-in programs did not carry over to 16-bit computers such as the Amiga and Atari ST in a significant way, as both programs and data (such as graphics) became much larger. It became common to include a covermount 3 -inch floppy disk or CD-ROM with each issue of a magazine. Description A reader would take a printed copy of the program listing, such as from a magazine or book, sit down at a computer, and manually enter the lines of code. Computers of this era automatically booted into a programming environment – even the commands to load and run a prepackaged program were really programming commands executed in direct mode. After typing the program in, the user would be able to run it and also to save it to disk or a cassette for future use. Users were often cautioned to save the program before running it, as errors could result in a crash requiring a reboot, which would render the program irretrievable unless it had been saved. While some type-in programs were short, simple utility or demonstration programs, many type-ins were fully functional games or application software, sometimes rivaling commercial packages. Type-ins were usually written in BASIC or a combination of a BASIC loader and machine code. In the