The CoCo3 came with 128K RAM, an analog RGB video port, enhanced 640x192 graphics capability, a 64-color palette and much more. (All ports contained on the CoCo 1 and 2 models were also available on the CoCo3, e.g. RS-232 serial, cassette, right and left joystick and a 40-pin expansion slot.)
The built-in Language, named Disk Extended Color Basic 2.1, was a Microsoft BASIC with enhancements by Microware. It was similar to that of the CoCo2, but Microware added the commands/functions to take advantage of the higher resolution graphics and text.
The CoCo3 was upgradeable to 512 KB RAM. (After-market RAM upgrades have gone as high as 8MB, with rumors that 16MB and 32MB RAM upgrades may also be possible). A Multi-Pak (a 4-port bus expander) plugged into the Expansion Slot allowed use of controllers for floppy disk drives, hard drives (MFM, RLL, SCSI and now even IDE), multi-port true RS-232 devices, MIDI units and much much more.
As its microprocessor was still an 8 bit (strange choice when Atari and Commodore were using a 68000), it couldn't access simultaneously to the 128k (or 512k), and thus used several RAM banks which could be switched (as the Thomson TO8, or MSX 2 computers).
Unlike the CoCo and CoCo II the 3 had an interrupt controller. This did away with a lot of the timing loops used in its predecessors, and actually took some of the fun out of programming in Machine Language.
Tandy made several prototypes of a Color Computer model IV but it was never released.
This was also my first computer since I owned a 2600 Atari and NES game system back in 1987. Learning basic was fun on this system with the built in color graphics. I remember bagging my parents for the floppy drive unit shortly afterwords and was able to save the basic programs and run games like Kings Quest. This was truly a revolution for the time and even had a special color monitor that could be purchased. What I was especially impressed about this system is all the expansion options that were available. When I was younger growing up I could all the options at once but being able to upgrade the system was an advantage along with having the composite video connection to get started.
One of my biggest regrets was selling my entire system for $50 USD and purchasing a 286 computer at the time. This system and the first IBM computer tough me a lot. The new generation of youth has a lot to be learned as we grew up in our generation.
Sunday 30th April 2017
Derrick Green (United States)
the Tandy was my very first computer. I spent hours of fun on it. back when you had to turn the little switch from TV to computer on channel 3 back then. I wish Ii held onto it now, it''sd be fun to mess around again on it. thanks for the fun., Jack