The TRS-80 Color Computer 2 is an 8-bit home computer released by Tandy Corporation in 1983, featuring a Motorola 6809E processor, 64KB of RAM, and improved graphics over its predecessor. It was designed for home users and educators, offering color display capabilities and support for BASIC programming.
Manufactured under the Radio Shack brand, the TRS-80 Color Computer 2 succeeded the original TRS-80 Color Computer (CoCo 1). It ran a version of Microsoft BASIC stored in ROM and supported cassette tape storage via a dedicated port. The system used a 16-key keyboard with a distinctive layout and included a built-in 5.25-inch floppy disk drive option through an external interface.
Unlike later IBM PC compatibles, the CoCo 2 operated on a Motorola 6809E CPU running at 0.89 MHz. This processor offered advanced features for its time, including a 16-bit accumulator and a 16-bit stack pointer. The system's graphics mode supported 320×200 resolution with 16 colors from a palette of 64, making it suitable for early graphical applications and games.
The TRS-80 Color Computer 2 used a custom motherboard with integrated video and sound hardware. The video controller, known as the Video Display Processor (VDP), generated color output using a composite video signal sent through an RCA jack. This allowed connection to standard television sets or monitors.
Sound was produced via a single-channel audio output capable of generating tones and noise. A built-in speaker provided basic audio feedback, though external speakers were often connected for better quality. The system had a 16-bit address bus and could access up to 64KB of RAM, which was standard for home computers of the era.
Expansion was achieved through a 68-pin edge connector on the motherboard. Users could attach peripherals such as disk drives, modems, and additional memory modules. The most common expansion was the 16K RAM upgrade board, which increased usable memory to 80KB. Some models shipped with 16KB of ROM containing the operating system and BASIC interpreter.
| Feature | Specification |
|---|---|
| Processor | Motorola 6809E @ 0.89 MHz |
| RAM | 64KB (expandable to 80KB) |
| ROM | 16KB (Microsoft BASIC, OS) |
| Graphics | 320×200 resolution, 16 colors from 64-color palette |
| Sound | Single-channel audio via 3.5mm jack |
| Storage | Cassette tape (via audio jack), optional floppy drive |
The TRS-80 Color Computer 2 came with Level II BASIC in ROM. This dialect supported string handling, floating-point arithmetic, and direct access to hardware registers. Programmers could write code that controlled the screen, played sounds, and read input from the keyboard.
For example, a simple program to draw a red circle on the screen might look like:
10 GRAPHICS 1
20 COLOR 4
30 CIRCLE 160,100,50
40 ENDThis code uses the GRAPHICS command to switch to a high-resolution mode, sets the color to red (color 4), and draws a circle centered at coordinates (160,100) with a radius of 50 pixels. The system interpreted this directly through its built-in BASIC interpreter.
Third-party software included games like *Star Raiders* and productivity tools such as *SuperCalc*. Developers also created assembly language programs for performance-critical tasks. The system supported machine code entry via the MONITOR command, allowing low-level debugging and direct memory manipulation.
The TRS-80 Color Computer 2 is often confused with the TRS-80 Model I and Model III, which used Zilog Z80 processors and were introduced earlier. The CoCo 2 is not compatible with software written for those models due to differences in instruction set architecture and I/O design.
Another frequent error is assuming the CoCo 2 had built-in floppy disk support. It did not. An external floppy drive interface was sold separately. The system relied on cassette tapes for program loading until users added a disk controller card.
A lesser-known fact: the CoCo 2's keyboard had a unique key layout with function keys labeled F1-F4 and a dedicated "RUN" key. This differed from the standard QWERTY layout found on many contemporaries. The keyboard also lacked a numeric keypad, which affected data entry speed in spreadsheet applications.
Despite being discontinued in the late 1980s, the TRS-80 Color Computer 2 remains active in retro computing circles. Enthusiasts maintain online forums, host emulation projects, and build hardware clones. The CoCo 2's BASIC environment is still studied for its simplicity and direct hardware access.
One user reported restoring a CoCo 2 purchased at a garage sale in 2019. After replacing the electrolytic capacitors and cleaning the keyboard contacts, the system booted successfully. They loaded a copy of *Pac-Man* from a cassette tape using a modern USB-to-RCA adapter and a Raspberry Pi-based emulator. The game ran at full speed, demonstrating the system's enduring functionality.
Modern emulators like WinFrodo and CoCoEmu allow users to run CoCo 2 software on contemporary devices. These emulators replicate the original hardware behavior, including timing delays and video refresh rates. Some developers have ported Linux distributions to the platform using custom bootloaders and minimal kernel configurations.