The Sinclair ZX-81 and the Commodore

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Two platforms at the Internet Archive currently provide the experience of loading programs from cassette tapes: 64. Both of these home computers flourished in the early 1980s, with use of them continuing longer based on the available hardware to users up until the 1990s. The ZX-81 itself faded before the C64, and the C64 saw transition to a (slow-reading) floppy drive that made cassettes fall out of favor as the decade moved on.

In both cases, there is the original data provided in a straightforward file; for the ZX-81 a .p or a .tzx tape data compilation, very small and compact. For the Commodore 64 cassette version, a .tap file with the information less compact, because the programs on the Commodore 64 could be significantly bigger.

To this extent, loading a program on the ZX-81 emulation can be demonstrated on the program One Little Ghost, a 2012 retro-make version of Pac-Man that stuffs a whole lot of game into a very limited phone number database system. Going to this emulation and starting it, you are faced with not an instantly loading, black and white remake of Pac-Man, but this:


Incomprehensible! Mysterious! Uninformative! Welcome to home computing in the 1980s!

This is the gap between today’s fast-food version of computer history, and trying to get things running in the original days of the hardware. We’re not even addressing the peculiar aspects of the ZX-81’s RAMpack, an externally attached device for increasing memory, that was legendary for just falling off while using the machine.


To make this interaction of software-emulated machine and actual machine at all clear, instructions were added to the items added to the Archive’s collection, including this intimidating set of movements and keypresses to be able to set a cassette loading.