Those of us who have experienced the rise of home computing can remember those afternoons waiting several minutes for our favorite game to load into our 8-bit microcomputer memory. Be it a Spectrum, an Amstrad CPC, a Commodore 64, an MSX or any of them. They all had this format in common. But, have you ever wondered what is the origin of the use of music tapes as storage?
The origin of the use of music tapes to store data
One of the most curious computer parts was the TV typewriter, an electronic device created by Don Lancaster, a terminal engineer for minicomputers. It was nothing more than a way to write directly on the TV screen, and its hardware didn’t run any programs. Lancaster was once asked if there was a way to record texts written in a certain way and not get lost, the solution he gave was simple. Give the TVT the possibility of connecting an audio interface to it, in order to record the data on a musical cassette.
However, the early TV typewriter design was not easy to build, many of its parts were already off the market and to top it off, it did not use RAM. Taking advantage of the huge success of the Don Lancaster kit and the lack of parts, a Datapoint engineer, Daniel Meyer, a company that had also been dedicated to the design of terminals, decided to design what would become the TV Typewriter II or CT-1024. The difference with the original model? The use of RAM memory, which has significantly reduced the number of parts in the kit, and for this the popular and widely available at the time Intel 2102 was chosen,
The particularity of the second model? The use of RAM allowed it to interact with a CPU. Thus, from the union of a TVT and the first 8-bit processors such as the Intel 8080, the MOS 6502 or the Motorola 6800, the first personal computers were born. Which include an audio interface not only for people to store their writing, but more importantly for programmers to store the source code of their programs once written and compiled from the same PC, without the need for an external minicomputer.
Because tape drives were so cheap as early as the 1970s, they became the first mass storage format for home computing.
It was the cheapest format at the moment
Most of the material in 8-bit computers of the day comes from the 1970s, when the most popular and cheapest format was music tapes or cassettes. Additionally, these allowed up to 100KB of data to be stored per side, which isn’t much, but taking into account that CPUs like the MOS 6502 and Zilog Z80 that used a 16-bit memory addressing, this means that was enough for these computers as they could only see 64KB of memory.
The first generation of 8-bit computers was barely 4 KB and was released in 1977, the second in 1979 worked with models with 16 KB of RAM, but by 1983 there were already models with 64 KB of memory. These systems could also use storage cartridges, but they were very expensive to manufacture and because they were accessible as read-only extensions to RAM, they were limited to 32KB.
For more complex CPU-based systems like the 8086, capable of addressing 1MB of memory and the 68000, with 16MB of addressing capacity. The storage capacity and access speed of a music cassette for storing data was insufficient. However, all of us from a generation remember fondly the load times of our Spectrums, Commodores 64 or Amstrads CPC tapes.
Finally, remember that cassettes have materially democratized the distribution of games. It was not necessary to have a large sum of money to make the ROMS for the games, anyone could write a program in the BASIC interpreter or in assembler, compile it, save the program to a tape and then download it. distribute.