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Last update October 30,2005

By Glen VanDenBiggelaar

March 9
Today, a new mystery has popped up for the CoCo 3. It seems that there are units out there with a "wire mesh Screen" underneath the vent slots. I have 3 units in stock right now and all three are US made units, none of which have the mesh screen. After a few e-mails, I have found out that none of the Korean made units possess this. It was suggest that these possibly could be Canadian units, but I was always under the impression that units sold here in Canada were just Korean units with French / English labels.It has been suggested that this is in fact more RF shielding, but the service manual makes no mention of it .I am looking into this.

March 1 2005

About a month ago, I got in my Brand new CoCo 3 from Cloud 9. I had also ordered the 512K upgrade kit. A lot of people had asked me why I chose Mark's kit, when I had a Tandy Kit and just had to get Ram for it. The ram for the Tandy Upgrade is becoming harder and harder to find. I had called all the suppliers here in town, and nobody carried it any more. In fact, I was going to have to order it from the States and that would have cost me more money that it was worth, so I opted for the Cloud 9 board. This board uses 2 -256K simms (which, also are getting harder to find) but Cloud 9 has them.

(Photo from Cloud9)
The Upgrade itself was straight forward. Mark and Boisy included a Very easy to follow "step-by-step manual. No PDF file here. and simply it was remove the case. Remove the old Ram. Cut 2 capacitors, plug in the new board, and you are done. The whole thing took less then 15 minutes, and they even include a test program. For those of you out there not running 512K, I suggest you get this upgrade. Its affordable and easy to install. This will also tide you over until Cloud9 revels the new superboard!

UPDATE JAN 27, 2005
Yes, I will admit before yesterday, I had not had a chance to look at a CoCo 3. I have been wanting one for years, and yesterday, one finally arrived in my shaking hands. I was scrubbing down an old CoCo 2 (16K), and I had set the new CoCo 3 down right beside at and looked closely at the 2 machines. The CoCo 3 I had received was an Auction on E-bay, and it was a MINT U.S. built unit (See link below on the differences between US and Korean units). The only 2 noticeable differences form the top looking directly down at the units is the Keyboard, and of course the label. The actual plastic Shell for the top of the 2 machines is virtually Identical in every way. I got a ruler out to measure for any "Design" differences, and the ONLY difference on the top was the little square "cover" over the Power supply in the vents at the top was bigger on the CoCo 3 (see Photo). Believe me, you had to look very closely at it to see the difference. I had stated earlier (from souses off the web, "that Tandy had "stream lined" the Case, I have fixed this to now say Motherboard). The keyboard was, truly, the best upgrade the CoCo ever had. You can see the progression to the now "Standard" Keyboard on modern Machines. I am convicted now more than ever, that if Tandy went a head with the CoCo 4 it would have been in the same case as they used for the "All in one" TRS 80 1000 (see photo). The only complaint I have on the keyboard is it is too loud, and I will have to get use too the noise level again. I have ordered a "Brand New Coco 3 from Mark at Cloud 9 (that is still in transport) so this will be my back up when that one arrives.

MODEL NUMBER 26-3334

1986 (or sometime around) Tandy again updated the CoCo. They gave it more expandability (up to 512 k) using a special upgrade board sporting faster RAM chips.. They again "stream lined" the Mother board and renamed it the "CoCo" 3. This one I am told was the most popular CoCo. A lot of  "Mod's" were done to this machine, with OS 9, you could even run a GUI interface similar to the Tandy Deskmate software.

First Released: 1986   CPU: 8 bit Motorola 68b09e Clock speed: 2 MHz (0.89mhz under RS-DOS for compatibility with FD expansion unit) Bus type: Tandy Proprietary Data bus width:  8 - bit Address bus width: 16 - bit Memory: 128k expandable to 512k (hobbyists have taken it 8megs) ROM: 32 KB Ports: 1 Cassette; 1 Serial ; 2 joystick; 1 RGB monitor; 1 RF modulated (TV); 1 RCA video; 1 RCA Audio; 1 cartridge/expansion slot
Display Screen size: 32x16, 40x25, 80x25 Resolution: 320 x 192 (16 colors), 640 x 192 (4 colors), 640 x 225 (2 colors) Storage : Tape and Floppy Operating System: Color Extended Basic; Disk Extended Basic; OS-9 Level II
The Tandy Color Computer 3 has been called by some the most powerful 8bit computer in the world. What made the CoCo3 so powerful was if you add a floppy controller cartridge, external floppy drive, a CM-8 RGB monitor and ran the CoCo3 using the OS-9 operating system. For those of you not familiar with it, OS-9 is produced by Microware, and is a UNIX-like multiuser, multitasking, windowing operating system that runs on a CoCo with 128k RAM, which is what the standard amount for a CoCo3 is. OS-9 is still supported by Microware, and in fact has even been used recently for such things as Set-top boxes.The CoCo3 was upgradable 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. Known Model Numbers: Only one model number is known: 26-3334 I have not even run across letter variants (EG:26-3334A)	Coco3 with Canadian Box (Ebay Photo)
The orginal pacaging that was shipped from both Korea and the US was this box. You can tell this is a US model by 2 signs. 1) English only wording 2) The word "Color" , not "Colour" like everywhere Else in the world.
Later in the CoCo's life, a more "kid frendly" Box was produced in order to get more parents to buy the system for the kids (ebay photo)

Back outputs of the Color Computer 3

Bottom Jack for the CM-8 Monitor

Tandy just had one version of the CoCo3's Manuals. "Introducing your Color Computer 3 and the "Extended Basic"
The Quick Reference Guide was also included.

Click here for a fascinating article By Mark Marlette on the difference between American vs. Korean CoCo 3's.
(It will redirect you to cloud9tech).

The Color Computer 3 stayed in production until 1990.

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