The Tandy Color Computer
The Tandy Color Computer 3
The Tandy (Radio Shack) Color Computer was one of those
classic 1980s computers that was so well-designed, many
people (myself included) still use them even today.
* Tandy Color Computers & Clones: Pictures
* What is the CoCo?
* Larry's CoCo Software for Download
* CoCo & 8-Bit Computer Links
Used CoCos can still be found for sale... search the net!
Tandy Color Computers & Clones: Pictures
Picture of the Sampo Color Computer
Click here to see a closeup of the Sampo Color Computer
and the ad appearing in the November 1982 issue of BYTE Magazine.
Picture of the Brazilian CP-400 Color II (Later Model)
Click here to see a closeup of the second version CP-400 computer from Brazil
Click on the pictures below to see the full-page February 1983
ad for the earlier Color Computers, or the 1984 Radio Shack
Catalog ads for the Tandy Color Computer 2
What is the CoCo?
The original Radio Shack Color Computer ("CoCo" for short)
was first sold in 1980. Standard was 4K RAM and Microsoft
BASIC, housed in a grey case, with chiclet-style keys.
Yet even with these humble beginnings, the CoCo has evolved
over the years, accomplishing tasks one would never have
thought possible for an 8-bit home computer.
The heart of the computer is a Motorola 6809E CPU. The chip
had many advances over similar chips of its day (such as the
Apple II's 6502 chip), and even at its original speed of
0.894Mhz (doubled to 1.78Mhz in later models), it's never
really sluggish. This may be hard to believe in today's
2Ghz world, but remember this machine doesn't use "bloatware"
like today's Macs and PCs do. The CoCo is quick, simple,
In an age when hardly anyone had even a 300 baud modem, this
little machine came with a built-in RS-232 interface that
could connect it to the outside world at speeds up to 9600 baud.
Even today, I use my CoCo3 (an updated version of the original)
to modem on the internet, at either 9600 baud through the RS-232
port, or 19,200 baud through a special RS-232 pak -- that's 19,200
baud from a computer designed during the age of 300 baud modems!
The main reason why I bought myself a CoCo back in 1982 was that
it has an incredibly strong Microsoft Extended BASIC. In an age
when, to draw a circle on an Apple II or Commodore, you had to
make FOR-NEXT loops with POKEs, all you need do on the CoCo is
enter CIRCLE (x,y),size -- and it would draw an instant circle.
One-word graphics and music commands made programming it a breeze,
and at the time, it was the only home computer with such a powerful
To store and load files, the CoCo uses either a cassette recorder
(at 1500 baud transfer speed), or disk drives (5.25 floppies that
store 156k on each side, with a max. of 4 drives). The disks use
the RSDOS (Radio Shack DOS) operating system that, like the CoCo's
BASIC, employs easy-to-understand commands.
A few years after the original CoCo, Radio Shack released
a white-cased CoCo with a better keyboard (calling it the
CoCo2), though inside, it was esentially the same machine.
The biggest advance was in 1986, when Radio Shack
introduced their final model of the CoCo -- the Color
Computer 3 ("CoCo3"). Still compatible with the older
models and software, the CoCo3 was leaps and bounds
ahead of the original. It offered multiple text displays
(to 80x28), graphics of 640x225, and a special CoCo3-only
chip called the GIME chip, that handles graphics and other
commands, freeing the main CPU for other tasks. Using the
GIME chip, programmers have made bouncing ball demos
better than those for the Amiga, and everything from
smooth-scrolling 3-D PacMan games to visual MOD players.
The back of the original CoCo has DINs for connecting to
a cassette recorder, a serial I/O port (for modem or printer),
an RF output (for connection to a TV), two joystick ports,
and on the side, a place to plug in either the disk controller,
or a "program pak" (game cartridges sold at Radio Shack). The
later CoCo3 model added RCA plug outputs (for video and audio)
as well as RGB outputs for an RGB monitor.
The CoCo also broke ground in another way: it was the first
MULTITASKING home computer. Using an operating system called
OS-9 (developed by Microware, and still in use today), it
allows multiple windows open, all running multiple tasks.
The original CoCo ran OS-9 Level I, and with the CoCo3, came
OS-9 Level II. The shell structure of OS-9 is somewhat
similar to UNIX... it's kind of a mix between Windows and
Unix, but was available to CoCo users LONG before anyone had
heard the words "Mac" or "Windows". There was once a local BBS
that ran on a CoCo3 with OS-9 Level II. It had two phone lines,
and allowed three callers to be on at once (1 local, plus two
via the phone), and on top of handling 3 callers, the sysop
would also often run background tasks at the same time -- all
this being handled at once by a little 8-bit computer! Amazingly,
the actual manufacturing cost of the CoCo3 was under $100 (which
Radio Shack sold in their stores for $399 when first introduced).
The CoCo3 came with 128k standard, and officially was
expandable to 512k, though outside companies sell memory
expansions of 1Mb, and even 2Mb. Among some of the other
products sold for the CoCo include an IBM PC keyboard
interface, making it easy to hook up a full-size external
IBM XT keyboard to the CoCo.
The original CoCo, the CoCo2, and the later CoCo3 were all
made by Radio Shack in the USA (though for a short time,
they were manufactured in Korea, until manufacturing moved
back to the USA). They were sold through Tandy-owned stores
all over the world, including Canada and Australia. There
were also a number of CoCo "clones" produced by various
companies. Tandy themselves cloned their own computer as
the "TDP-100" (same as a CoCo2, but these models were
meant to be sold in stores like Kmarts rather than in
Radio Shacks). In the UK, one of England's most popular
home computers from the 1980s was the "Dragon" computer
from Dragon Data -- almost an exact CoCo2 clone (with
a better keyboard, and a few minor changes). Later, a
company called "Tano" began officially marketing the
"Dragon 64" computer in the US. (For those interested,
a company called "California Digital" in Torrance,
California, still has plenty of brand new, never-opened,
U.S.-version Tano Dragon 64 computers in stock for
$35.00. Their phone number is: (310)217-0500. Again, the
Dragon 64 is a clone of the CoCo2, not the CoCo3.
California Digital does have a web page, but the
Dragon 64 isn't listed on it, so you'll have to call them
or email them to order one). In Japan, the huge computer
conglomerate Fujitsu's first entry into the (Japanese)
home computer market was by way of the Fujitsu FM-7 home
computer -- a CoCo-inspired (though not a clone) computer.
(The FM-7 uses two 6809s instead of one, but its F-BASIC
is basically Microsoft's CoCo BASIC with additional
commands to handle the Japanese language and other
enhancements. It was based on the CoCo platform, and
ran many CoCo programs and operating systems, such as OS-9,
and FLEX. In 1997, I finally got my hands on an actual
Japanese FM-7, and have been tinkering with it ever since).
CoCo clones were also found in Brazil and Mexico, though with
the exception of Mexico, all the clones were based on the CoCo2,
not the CoCo3. (Mexico had its own versions of both the CoCo2
and CoCo3). There was also a clone of the CoCo made by Sampo,
briefly advertised in the November 1982 issue of "BYTE"
magazine, though it never made it to store shelves, at least
in the U.S.
In the end, the thing that still keeps die-hard CoCo users using
their old little 8-bit machines is the fact that the CoCo has
always somehow been able to keep up with the latest computers.
About the only thing it CAN'T do is view graphical web pages,
though by using LYNX, one can surf the web with text. But if I
want to see a GIF, play a MOD file, or write my Master's Thesis
(as I did on my CoCo3), this little 8-bit wonder never ceases
to amaze. For those of you who find this hard to believe,
I don't blame you. Radio Shack never really supported the
CoCo, and it always remained somewhat of a "hidden" machine --
to people just looking at its outside, it looked like a toy, and
they'd never guess that their local two-line BBS handling three
callers simultaneously was being run on this little machine.
Radio Shack finally stopped selling the CoCo3 sometime around
1992. Though the CoCo3 had many prices (from $399 down, as time
went by), by the end, some Radio Shack clearance stores were
selling them for as low as $29 (with the disk drives and RGB
monitors going for as low as $49 each).
Today, there's a loyal group of CoCo users the world over,
brought together by the internet. There's a CoCo Listserv
(available on usenet as: bit.listserv.coco -- though as of
2004, most have moved over to a new CoCo group on Yahoo),
there are still new programs being released by professionals
and tinkerers alike, who can't stop being amazed at this little
machine. As well, there are CoCo2 emulators for both the Mac
and PC, and a fantastic PC CoCo3 emulator.
In August 1996, I bought my first non-CoCo computer -- a Toshiba
120Mhz Pentium laptop with 12.1 TFT and 6xCD-ROM. At the time I
thought I'd be using it everyday, and finally throw my CoCo setup
into the closet. Boy was I wrong. Not a DAY went by when I didn't
use my CoCo to check email, write a letter, or play games.. and at
most, I took out my laptop maybe once a week. No kidding. With the
time it took to boot up my PC and a term program, I could already
have checked my email with the CoCo. The same goes for writing
a letter. With the CoCo, you get almost "instant" action. When
you turn the power on, you're ready to go. No boot time. When you
load a program, it takes maybe 3-4 seconds. Everything is fast,
simple, and easy. And in ALL the years I've had my various CoCo
systems -- from the early grey-case CoCo1 to my current CoCo3
I bought 12 years ago, it has NEVER crashed or needed repair.
Not once. How many of you out there can say that for your PCs
and Macs? You who can't get your new software to run right. Or
who get STACK OVERFLOW errors everytime you try to go too fast.
And by the nature of the type of computer it
is, the CoCo can never catch a virus over the
net. I'm not trying to knock PCs or Macs...
I use them too. I'm just pointing out the
appeal of sticking with the CoCo -- the
efficient simplicity of a machine that handles
everything I might want to do, with never a
problem of any kind. As the internet has moved
to broadband, I obviously now use my PC more than
the CoCo, but for its time (and beyond), it was
The CoCo is a great little machine. It invites
tinkering and invention, and in recent years,
programmers have pushed the bounds as never
before. I think I can honestly say that if
I had purchased a Commodore 64, Apple II,
TI994A, or Atari 800 -- as fine as those
systems were -- I wouldn't still be using
them today. There's a reason why people just
will not give up their CoCos. These things
were the best-kept secret of the 1980s, and
are still easy and fun to use. :)
Click here to read a short story about the uses one
Chicago-area bank had for CoCo2s in the 1980s!
New for 2000: "Gate Crasher" by Nick Marentes -- a fast,
5-level 3D "Doom"-like game on an 8-bit computer! (CoCo3)
Some other CoCo3 games by Nick Marentes:
PacMan, Space Intruders, Rupert Rhythm
Larry's CoCo Software for Download
The CoCo was a machine that invited programming by its user, and over
the years, I've written many programs for the CoCo. They're not all
flashy or mind-bending, but they do the job, and I'm proud of them
(many I wrote years ago while still in jr. high, though I've never
stopped programming the CoCo... it's just too much fun!)
Software with an "ARC" extenion requires an un-ARCing program, such as
The Compressor. Programs with a "DSK" extention are not Emulator DSK
files, but rather, DSHRINKed files, and require Dshrink to un-shrink.
"BIN" programs are straight binary, and "BAS" programs are done in BASIC.
All software is now, and has always been freeware!
TC40.BIN Use this utility program (not written by me) to uncompress any
CoCo ".ARC" program. Works on a "real" CoCo as well as on CoCo emulators.
ARC on the CoCo is something like what ZIP is in the PC world today.
If you want to run any CoCo program that has been compressed (.ARC) you
need to run this program first to un-compress the ARC file.
JAPAN12.ARC A complete Japanese (hiragana and katakana)
writer and editor for the CoCo3.
CLUE.BAS The board game of Clue for any CoCo with at least 32k.
Did Col. Mustard really do it with a rope in the library? It's a game
of wits and skill, and your opponent is none other than the CoCo
itself -- who's also trying its hardest to solve the puzzle before
you do! NOTE: You MUST do a: PCLEAR1 (ENTER) before LOADing or
RUNning this game in order to free up enough memory. Don't forget!
CC3CLUE.ARC The CoCo3 version of COCOCLUE. Basically the same game,
but the screen is enhanced, and easier to read.
STOCKS.BAS A fun game where you play the stock market. Try to
make it big, but watch out for bankruptcies! For any CoCo with 32k.
SUNDRIVE.ARC A 512k CoCo3 animation "flip" demo of
a Sunday Driver.
LDGDEMO2.ARC My second 512k CoCo3 "flip" demo.
STRDEMOS.ARC A set of "Starry Demos" -- nice little screen-saver-type
demos to run on any CoCo3.
SPACE.BIN A wacky little demo showing what happens out in space.
For any CoCo3.
SCROLART.BIN is a nice little screen-saver-type demo of different
line-art designs scrolling by. CoCo3.
FUNDEMO.BAS A strange little demo that shows some of the tricks
you can use within BASIC. Any CoCo3.
FNTMANIA.ARC A collection of different English type fonts,
as well as Japanese hiragana and katakana fonts for use on your
CoCo3 (via HSCREEN).
AUTOPLAY.ARC A program that will automatically scan a disk,
recognize any LOADM & EXEC music files, and play them like
a jukebox. CoCo3.
28LINES.BAS A short program that will give you an 80x28 text mode
on the CoCo3. Included are some remarks on how to change the colors.
MACSPACK.DSK A collection of my different digitized sound players
for the CoCo3, including a few sample sounds. Requires a 128k CoCo3,
though 512k gives you more room for sounds.
WATRFALL.ARC is a great little demo of a waterfall, complete with
sound. Taking Chet Simpson's Waterfall Demo, SockMaster's background
sound player, and a few other things, I mixed everything together to
create a moving-waterfall-with-sound demo. For 512k CoCo3.
Below are links to other Color Computer-related pages on the net,
(including those owned by some of the programmers still churning
out new CoCo software), as well as some links to non-CoCo related
pages (dealing with other old 8-bit computers).
If you're looking for an archive of public-domain CoCo programs, you can
get files via FTP. The address to FTP to is: os9archive.rtsi.com
There's both an RSDOS directory, and an OS-9 directory, as well as an
"incoming" directory for you to upload files into. Note that the ftp
site is CASE-SENSITIVE, so it DOES matter if you type in lower or
Click here to go to the RTSI FTP site containing lots of
RSDOS CoCo programs for download.
The CoCo Homepage is one of the most complete CoCo pages I've ever
seen. Includes lots of scans, pictures, news, and about a million
CoCo links. Check out the old page as well as the new page.
Sock Master, one of the most prolific CoCo programmers,
has his own web page. On it, you can find downloads of his
many demos, utilities and programs, as well as information on
hardware hacking, and many CoCo links.
Nick Marentes of Australia has been a long-time CoCo programmer,
and keeps a great web page. On it, you can find many of his old
professional arcade games now availble for free download, as well
as information (and free demos) on his great new games, including
"PacMan" (1998) and "Gate Crasher" (2000), a 3D "Doom" type game.
Also, the page features an on-going CoCo Programmers Interview
project, with new, recent interviews of famous CoCo programmers
past & present (everyone from Rick Adams to Jeremy "Zenix" Spiller!)
Jim's CoCo Page is yet another good CoCo page to check out. Jim
is now in charge of CoCo Friends Disk Magazine, and is also the
source to pick up tons of great "CoCoPro!" and "Sundog" software
titles for a great price -- $5 each for CFDM members, and just
slightly more for non-members.
A CoCo in a Toyota Pickup? Yup. Check out the Coyota page!
Ron Delvaux has a nice Vintage CoCo page.
Here is good Japanese-language page on the entire series of
Fujitsu "FM" personal computers (FM-7, FM-77, FM77AV, FM8, etc).
Ricardo Ferreira has a great English-language page on the
Brazilian version of the CoCo, the "CP-400", including images
and software (in English and Portugese) for download.
Allen Huffman keeps a good CoCo InfoPage, worth checking out.
Roger Hallman's CoCo World has lots of nice stuff, including
information on his own program, CoCoIII Pages.
The CoCo Chronicles contains detailed information on the history
of the Tandy Color Computer. Great reading!
For those of you interested in replacing your standard Windows
start-up screen with something a little nicer (such as a picture
of a CoCo screen!) go here to download the program!
Another nice Windows program for download is a CoCo/Dragon
Check out BYTE Magazine's original 1981 article called
"What's Inside the Color Computer".
Techno's CoCo Page has lots of interesting things to see.
The CoCo Friends Disk Magazine Archive allows you to browse all the
back issues of the popular CoCo Friends Disk Magazine from 1992 to 2000.
Be sure to check out Jeff Vavasour's page. Jeff wrote the original CoCo3
Emulator for the PC, and his page has lots of interesting items on it.
Cup Of CoCo has some nice areas to check out,
including lots of CoCo arcade games for download.
Bill Yakowenko's excellent CoCo Page is definitely worth a look.
The World Of 68' Micros (a hard-copy magazine devoted to
Motorola 68XX-based machines) now has a web page. It's here.
The budding CoCo Preservation Society is worth checking out.
Steve McCoy keeps a great, informative page on Radio Shack's
CoCo, Model I, and Model IV computers, including a comprehensive
article/program index for Rainbow Magazine. Check it out!
A great page on programming the TRS-80 MC-10 Micro Color Computer
(as well as general information on the machine) is here.
Not specifically CoCo-related, but a blast from the past
nonetheless, is this page by Bill R., with color scans from the
1978 Tandy Computers Catalog. It's amazing that so many different
home computers could be bought from Tandy/Radio Shack way back
in 1978 (most of which were NOT made by Tandy!)
Jim Agar keeps a web page on various things, including old
computers. Of special interest is his new Interact page, one
of the few pages out there dedicated to the virtually unknown
"Interact" Home Computer (see my "Other Computers" page).
Stefan Mansier of the Netherlands keeps a page on his
classic computer collection. Check it out by clicking here.
EmuCompBoy has just started a web page showcasing some of his
projects, including the new Virtual APF Imagination Machine emulator
for the PC (different than the one currently available on my APF Page)
as well as the PC Virtual MC-10 Micro Color Computer emulator.
Click here to return to the 8-Bit Computer page,
or here to return to the main page.