What is a CoCo?

In 1980, Tandy released a new computer though its Radio Shack stores, the TRS-80 Color Computer (AKA CoCo)
It was a radical departure from the TRS-80 series, since it was based on the Motorola 6809 CPU, had a color screen, and the target audience was the home user.
It was born from a joint venture between Tandy and Motorola, initially with the goal of creating a low cost Videotex terminal. This would evolve and become a general purpose computer.
The initial CoCo was available with 4 or 16 Kb of RAM, and 8 or 16 Kb ROM. By 1982 the 4 Kb model was out, and a 32 Kb became the top of the line.
In 1984, the CoCo 2 was released. It was mostly a revision, with an improved board and keyboard, but the specs remained basically the same. It was available only with 16 Kb of RAM, and the CoCo 1 was still offered, with 64 Kb. A 64 Kb CoCo 2 was eventually released in 1985.
Then, in 1987, the things changed.
The 16 KB model was discontinued, and the new, much improved CoCo 3 came to light.
It was available with 128 or 512 Kb of RAM, and had a new 32 Kb ROM. Graphics capabilities were greatly enhanced, and this time included connections for monitors, not just TVs.
The CPU was still the 8 bit, Motorola 6809, that would run up to 1.79 MHz. This made it less powerful than the Amiga and Atari ST computers, but the base price was about a quarter of those (219 vs 800-1200).
In 1989 the CoCo 2 was discontinued, and in the 1991 catalog, the CoCo 3 was just give 1/4 page, and disappeared in 1992.
But that was not the end.
As of 2018, the CoCo is still alive, can be upgraded to 2 Mb of RAM, connected to any modern monitor, run a real-time, multi-user, multi-tasking, still in developement OS, and load software from tapes, cartridges, floppy disks, SCSI/IDE disks, Flash cards, and even directly from the web.