Tandy/Radio Shack Color Computer 2



My first working computer system--64K CoCo 2



I'll always have a certain fondness for these machines. I guess I am not alone. The system shown above was my main computer for quite awhile. I later added disk drives and a better printer to the system. Many people still use and program these computers. The Color Computer (versions 1,2, and 3) has always been a very popular hobbyist computer. There were many magazines and newsletters devoted to it. Even now, you will find there are many web sites and web pages devoted to these computers on the Internet. And the Color Computer has been affectionately nicknamed the CoCo.

This is a "rusty but trusty". The small label to the right of the nameplate shows that this computer was upgraded to Extended Color BASIC. This machine has 16K RAM.

I started out with a Timex-Sinclair 1000. I had lots of problems with that machine, the main one being system "crashes" when using the optional 16K memory pack. The Color Computer was diferent. It was a very stable machine. I never had hardware "crashes". It had a usable keyboard, color graphics, and even had limited sound. It also loaded and saved programs and data reliably on standard audio cassettes. The CoCo 2 uses a Motorola 6809 CPU.

The CoCo2 was the succesor to the original Radio Shack TRS-80 Color Computer (a.k.a. CoCo). It is a smaller unit, and has an improved keyboard. The first model had a "chicklet" keyboard. There were many changes in the design to help reduce the production cost of the machine. Even during the production of the CoCo 2 there were various keyboard and motherboard changes to reduce costs and keep the pricing competitive with other "home" computers. It's main rivals were the Commodore 64, Atari home computers, and the Texas Instrument TI 99/4a.

The rear panel has a power switch, RF channel selector, RF output jack, L/R joystick connectors, seial port, and a cassette I/O connector.

There are various versions of these machines floating around. Some have the Tandy name, others have the Radio Shack TRS-80 logo. There were some sold as Tandy TDP-100 's. The TDP-100 machines were not normally distributed through Tandys' Radio Shack stores. There were three main versions of these machines. The base version had 16K of RAM and Color BASIC. The better versions had Extended Color BASIC, in both 16K and 64K RAM versions.

The computers were sold as "home" computers. They included the hardware necesary to hook the computer to your television, (color recommended). You could buy a cable from Radio Shack that let you hook up your portable cassette recorder to load and save programs on cassette tape. Radio Shack and others also sold programs on Program Packs. These packs attached to a port on the side of the computer. They loaded instantly and included games, word processors, database, and other types of applications.

The diferent versions of BASIC in these computers were all based on Microsoft BASIC, and customized for these machines. The two higher levels of BASIC available were extensions of the lower versions. Color BASIC was the smallest version of the language, and was supplied with the base model. Extended BASIC had all the features of Color BASIC plus many additional commands and features. The final upgrade was Extended Disk BASIC. You had to have Extended BASIC installed in the machine to use disk drives with these computers. The disk drive kits for these computers had the disk controller built into a Program Pack like those we talked about earlier. These Packs were slightly larger than game packs and had all the control circuits for the disk drives (up to 4 drives!), and the Disk Extended BASIC language which had all the necesary commands to format, save, and read data to diskettes. The drives used 5.25 in. single-sided double-density diskettes. You can use double-sided diskettes too.. the same type of diskettes the IBM PC used. Just make sure you format them in the Color Computer drive. The BASIC language is fairly standard. I have converted some Color Computer programs to run on an IBM PC.

This picture shows the port where you insert Program Paks, disk controllers, etc.

Another cool thing you can do with these computers is run the OS/9 operating system. It requires a 64K system and disk drives. OS/9 is very much like the UNIX operating system used on mainframe computer systems. It is a multi-user, multi-tasking system. Radio Shack sold OS/9 and also some programs that ran under OS/9.

These are neat computers, but nothing is perfect. The normal text screen for these machines is only 32 characters wide. Most CoCo 2s had no true lower-case charater set. Lower-case letters were displayed on the screen in reverse video. This is fine for many things, but is definitely not the hot setup for spreadsheets or word processing. I'm sure they set the display up this way so it would be compatible with the resolution of your average television. There were some programs which could use the graphics mode of the computer to give you a 51 character screen width. That is a big improvement, but still nowhere near the standard 80 character screen width of office computers. These computers also have a serial port, but no parallel port. You can use a serial printer (Radio Shack sold several compatible models), or there were serial to parallel converter available if you needed or wanted to use a parallel printer.

Tandy sold many accessories for the CoCo 2. You could buy joysticks, a 300 baud Modem Pak, a Multi-Pak interface which held 4 Paks at a time, and many more. Other companies have developed hard disk drive systems, IDE disk interfaces, and many different types of hardware and software for these machines.