TRS-80 Color Computer Emulator Page
Last updated May 11, 2001


This program emulates a complete
TRS-80 Color Computer configuration including:
MC6809E Micro-Processor running at .8948 MHZ
8k Standard & 8k Extended BASIC ROM memory
16k Cartridge memory
4k, 16k, 32k & 64k RAM memory options
MC6847 VDG & MC6883 SAM controllers
The following graphic modes are supported:
Text 32 x 16 Text
SG4 64x32 Block graphics
SG6 64 x 48 Block graphics (4 color)
SG8 64 x 64 Block graphics
SG8a 64x96 Block graphics (4 color)
SG12 64x96 Block graphics
SG12a 64x96 Block graphics (4 color)
SG24 64x192 Block graphics
SG24a 64x192 Block graphics (4 color)
G1C/R 64 x 64 graphics (2 & 4 color)
G2C/R 128 x 64 graphics (2 & 4 color)
G3C/R 128 x 96 graphics (2 & 4 color)
G6C 128 x 192 graphics (4 color)
G6R 256 x 192 graphics (2 color)
G6Ra 256 x 96 graphics (2 color)
COCO 2 mode supports lowercase & inverse video
60hz & 63.5ns video interrupts
Standard keyboard
Standard joysticks (2)
Built-in serial port
Cassette port sound
Creation of real cassette tapes loadable on a COCO
CCR-81 cassette recorders:
- Virtual recorder saves & loads from
   virtual cassette files
 - Wave recorder saves & loads from Wave sound files
Fully emulated Multi-Pak Interface

Hardware Cartridges Emulated:

Disk BASIC & FDC Cartridge
 - 100% compatible WD1793 floppy disk controller
 - NMI & HALT supported
Orchestra-90 Music Synthesizer Cartridge
 - Sound output to PC speaker, SoundBlaster
   or Wave file
Deluxe RS-232 Program Pak
 - Uses a PC serial port
 - Supports NMI & FIRQ interrups
 - Supports 50-19200 baud
Direct Connect Modem Pak
 - Uses a PC serial port
 - Supports NMI & FIRQ interrups
 - Support 50-19200 baud
3 double-sided & 1 single sided
double-density 80+ track drives
In addition to the standard Color Computer configuration the emulator also supports:
A point & shoot configuration screen with: 
 - Unlimited configurations selectable at start-up 
 - All system options and virtual disks saved on exit
A point & shoot virtual floppy selection screen with: 
 - Ability to open and create new virtual disks 
 - New & powerful virtual disk format able to do 
   everything a real  floppy disk can do 
 - Able to read & write other emulators JV1 & JV3 disks 
 - Ability to boot, read, write & format REAL COCO 
   floppy disks in a compatible PC drive
A virtual cassette recorder control screen with: 
 - Ability to open and create new virtual cassettes 
 - Controls just like a real cassette recorder 
 - Feature to force cassette motor on
A Audio/Wave cassette recorder control screen with:
 - Ability ot open and create new audio Wave files
 - Controls just like a real cassette recorder
 - Ability to load real COCO tapes using SB line input
 - Ability to save cassette port output to Wave file
 - Ability to load Wave file recordings of tape programs
 - Feature to force cassette motor on
Multi-Pak Interface allows loading of up to 4 ROM/Hardware cartridges.
 - A point & shoot cartridge selection screen
 - Support for 32k & 64k ROM cartridges

The emulator also maintains a .CAR file for each ROM image that contains:
 - Title & description of cartridge
 - Label & text color
 - Length of ROM image
 - Hardware options for cartridge
The .CAR file is automatically created when a new cartridge ROM is loaded and is user modifiable.
Computer Type
 - COCO Standard BASIC or Extended BASIC
 - COCO2 Standard BASIC or Extend BASIC
Serial port I/O can be sent to a PC printer, PC file or PC serial port.
Emulator can support up to 3 simultaneous serial
 - Built-in
 - RS-232 Pak
 - Modem Pak
2 user selectable fonts (Standard & Lowercase)
 - Fonts are files which can be user modified
2 user selectable keyboard layouts (PC & COCO)
 - Keyboard layouts are files which can be user modified
   to create custom keyboard layouts
The color palette is a file enabling the COCO's colors to be user modified
Ability to save & load system snapshots
Ability to load .BIN files directly from a PC directory
Ability to load .PAK format cartridge files
Ability to drop to a DOS prompt
Emulator speeds are accurate to .01% of a real COCO's for true sound and game play, plus:
 - Hot-key speed selection of .447, .895, 1.79, 3.58 MHZ
   & Turbo
 - Turbo speed is limited only by your PC's speed
 - An override speed can be set & locked so the COCO
   runs at user selected speeds transparent to COCO OS.
Color artifacting option for graphics mode G6R. This option closely emulates colors created on a color TV when in the 256 x 192 graphics mode.
 - Option can be disabled
   or set for Red/Blue, Blue/Red colors
PC mouse, PC joystick & arrow keys emulate
COCO's 2 joysticks
Hardware clock (memory mapped)
PC mouse support (memory mapped)
PC to COCO file I/O (memory mapped)
Enhanced instruction set including instructions to: 
 - Open, close, read, write PC files 
 - Read, change & display the PC directory 
 - Execute DOS commands
 - 8, 16 & 32 bit multiply and divide functions
 - Ability to read and write to PC I/O ports & memory
Amplifier for cassette & Orchestra-90 sound: 
 - PC speaker 
 - SoundBlaster Pro/16/32 ISA

System Requirements: 

  • A Pentium 75mhz compatible system
  • 640k memory w/512k free
  • VGA card 
  • MSDOS 6.x or Windows 95/98

Optional Requirements: 

  • Pentium 166mhz, for 3.58mhz operation
  • SoundBlaster SB16 or SB32 or 100% ISA/PCI, DOS compatible card 
  • DOS or Windows compatible Mouse 
  • DOS compatible Joystick

Download Emulator

Version 1.22

Color Computer Software

I have started scanning and preserving COCO software and documentation. Currently I have only done cartridge software but I will soon add disk & cassette tape software too.

Color Computer Software Pages

Color Computer Emulator Documentation

The first revision of the COCO emulator documentation has been finished. The documentation should answer most question about the emulator's functions.

The following link will take you to the Color Computer emulator on-line documentation:

Enhanced MC6809 Instructions

The emulator has a set of enhanced MC6809 instructions. These instructions allow COCO programs to interface with the PC's disk drives, ports, memory and other hardware. These instructions also add high level math functions to the MC6809 instruction set.

There are currently no COCO utilities for transfering files between the COCO and PC worlds. There are also no COCO drivers for using the hardware clock or accessing a virtual hard drive. These utilities can be written on the COCO using the enhanced instructions available in the emulator. Anyone wanting to develop COCO utilities and drivers will find the enhanced instruction documentation very helpfull.

NOTE: These instructions are only available in the emulators.

The following links contain a list of the enhanced instructions and documentation for each instruction.

Enhanced Instruction Documentation (on-line)

Enhanced Instruction Documentation (Microsoft Word 96k)

Color Computer Emulator News

Version 1.22 fixes an error that caused the emulator to lockup when selecting a cartridge (very rare).

Version 1.21 has RS-232 & Modem status lights that were left out of the v1.20 update.

The on-line documentation has been updated.

I have added support for the RS-232 & Modem Paks in version 1.20.

I have also fixed the floppy disk rotation speed which was emulated a little fast.

I have added the RS-232 & Modem cartridges to my COCO Software Pages. I have also made a new section for COCO disk software.

Version 1.10 of the COCO emulator has some major changes and a few bug fixes.

I have also updated the documentation and added the COCO Software Pages.

Version 1.01 of the COCO emulator as a few changes to the enhanced instructions and memory mapped functions.

I have also finished the documentation for the new Color Computer emulator. There is also technical information about the COCO and the emulator, including file layouts and memory maps.

Version 1.00 of my new Color Computer emulator has been posted. All the standard hardware is supported plus the Multi-Pak, Floppy Disk Controller & Orchestra-90. There are no DOCs for the emulator yet but it is based on the Model 1/III/4 emulators so most of the functions are the same as in the TRS-80 emulators. If you are unfamiliar with my other emulators check the TRS-80 on-line documentation for an idea of how the new emulator functions. Check the Color Computer 1 & 2 Emulator Info Page for all the currently supported features.

There is no documentation for the Multi-Pak Interface. The F4 key brings up the Multi-Pak screen and then you can then insert up to 4 cartridges and select them using the Multi-Pak select switch (just like a real Multi-Pak).

Note: To use the virtual floppy drives you will have to insert the disk cartridge into the selected slot and reboot.

In addition to the normal reset key (F10) the COCO emulator has a new power-up reset (Shift-F4). This new function clears the CPU memory so the system does a cold boot like at power-up. Use the power-up reset after changing cartridges or running programs that leave the COCO in an un-resetable condition.

This version is still a work in progress. There are likly to be bugs (undocumented features) and functions may change in future releases.