DEPARTMENTS
MORE MARSHMALLOWS
LOAD 'eM
COCO LINKS
SCRAPBOOK
LETTERS TO THE LOUNGE
OTHER TANDY COMPUTERS
E-MAIL THE EDITOR
ABOUT QuarkX

Last update March 28,2005

By Glen VanDenBiggelaar

UPDATE March 3, 2005
The Color Computer had many different "OS'S" or operating systems, but only 3 Main ones were officially sanctioned and sold by Tandy. They were BASIC (officially called Tandy Basic-Lincenced By Microsoft) , Disk Extended Color Basic ( by Microsoft and Tandy) , and OS09 ( Licence by Microware). There were many others, but the focus of this page will be mostly the 3 "common" .

TANDY (RS) (Microsoft) BASIC
Not very many people want to admit it, but ever since computers were made available to the average consumer, Microsoft had the first operating system installed. From Apple to Zenith, Microsoft was there. This was back before individual "Licensing" of the OS, and Tandy Paid a "lump sum" for Basic. A Snip from a Microsoft book says Tandy initially paid $50,000 for Basic, a bargain, when later companies like Texas Instruments paid $100,000. This was actually a good price, considering all the time and money Tandy would have had to spend doing it "in house".
Tandy was one of the first customers of Microsoft, in fact, probably the second after MITS and the Altair . Tandy Licence Microsoft Basic for use in all their computers. The Color Computer, had probably the most complete forms of Basic compared to most of its Competitors for the time. Right from the launch of the Color Computer, Microsoft was involved. Tandy was committed to make Basic easy and understandable to it's customers and created one of the best manuals ever written for basic and shipped it with every computer. The Manuals were not written like other books at the time, but catered to kids and "Non-technical people.
The early Color Computers had shipped with only 4K of Rom, so Microsoft had to "strip down" Basic to fit into the memory space. This was not a big deal as most machines at the time came with this size limitation. Later, Tandy decided to"bump up" the Rom space into 2 16K chips and "Extended Basic" was introduced. It wasn't until half way through the CoCo2's production, that Extended Basic was standard on every machine. Why (other than Cost) remains a mystery today. Some of the more "noticeable" limitations was in early machines (not just CoCo), lower case letters could not be displayed on the screen.

Original "Getting Started" The manuals were oversized. 17"x8", which made them dificult to use at the computer, for always it ended up one ones knees.	Original "Extended" Basic Manual	Boot screen for Color Computer 1 Extended Basic
Original Manual for CoCo2. No difference (other than cover ) the CoCo1 . As far as I can find out, Tandy had no real "cut off" for these old manuals, as some late Model CoCo2 also had them	Original Extended Manual for CoCo2. Again No difference but cover	Boot screen for Color Computer 2 Extended Basic
Tandy started shipping the CoCo2 later with these smaller,"Introducing Your Color Computer" Guides, Which were just the ordinal"Operation Manual" rewritten.	Tandy also re-sized the Basic Manuals. Because most people bought the extended Basic, these manuals are rare. Tandy also used pink ink in these books, instead of green, and refer to the CoCo 2 as the Deluxe Color Computer.	When Tandy decided that all their machines would be shipped with extended basic, Tandy re-issued the books. Into a smaller, more "standard" size, combining the Getting Started and Extended manuel into one Thick Book. Why they kept the name "extended basic" and just didn't re-name it "Basic" is beyond my knowledge.
CoCo 3	CoCo 3 Extended Tandy only released the CoCo 3 with Extended Basic.	Boot screen for Color Computer 3 Extended Basic 2.0 with Microware credit

Disk Extended Color Basic (DECB)
When Tandy decided to offer a disk drive to the market for the Color Computer, They included in the controller's Rom, Microsoft's and Tandy's own Disk Extended Color Basic . With Disk Extended Color Basic in the Rom of the disk controller, Tandy probably thought that this would all but eliminate any competition with other versions of DOS. Tandy decided to call it " Disk Extended Color Basic" . Many People argue that this is not a "True DOS" but a hybrid of MS BASIC. Third party companies quickly thought of "work around's" and started to sell Disk controllers with EPROMS installed, and switches so the end user could "chose a flavor. I am even sure that a lot of people with EPROM burners quickly un soldered the ROM and put their own Flavor of DOS in. One of the known limitations with DECB and the controller chip was that it couldn't address double sided drives or High Density Disks, which is why Tandy never made a 3.5" drive for the CoCo.The tools and technology was available to Tandy, but, Tandy never made it available for the CoCo (probably due to its commitment to it's more expensive computers).
Mike Pepe has also added:
"The design of the controller used the same components as the other products in the TRS-80 line- obviously to reduce cost as these were already stocked components.
From the software side, an extension to Extended Basic is contained in a ROM in the disk controller, which gives the user Disk Extended Color Basic when the CoCo is powered on with the disk controller attached. This is cometimes referred to as "RS-DOS", which is debatable terminology. Some will argue that Disk Extended Color Basic is not a DOS, and that the "True" DOSes for the CoCo are OS/9, FLEX, etc... (I personally happen to feel that way as well) If Radio Shack thought DECB was a DOS, they wouldn't have a command called DOS to get out of it, right? The downside to this ROM-based "DOS" is that compatibility must be maintained with previous versions. It is for this reason that even though Radio Shack did eventually ship 40 track single and then eventually 40 track double-sided drives, Disk Extended Color Basic remained stuck at a 35 track single-sided disk environment, to make sure that even the oldest CoCos could use disks made by newer systems. Many CoCo users patched their ROMs or bought third party "DOSes" to get more out of their systems. Of course, these patches and/or third party replacements often sacrificed compatibility with folks who didn't have that particular company's ROM or their stock ROM patched in the same way. Also some programmers wrote their own DOSes (programs like Disk Scripsit and Edtasm, as well as others) which ignore the DECB rom entirely... combine these factors and you really have a mess!
The WD1773 disk controller is physically not capable of running high density disks, and the 3.5 inch form factor was not what the CoCo was built around. No other reason that that to speculate as to why we never got 3.5 inch drives in the CoCo world. "
I can't comment more on DECB yet. I never had a disk drive when I was growing up. I had only used Basic and a cassette drive. I have drives in transport, and will update this page in due time.

The Disk System Manual . This again was a very large book (8.5"x11"). Tandy must have belived Biger was better	the Tandy re-issue with coil bindings for the FD 501. This was a smaller "book" size	Tandy then "Re-issued" again, possibly just for the FD 502, To have the coverwork match the CoCo 3's Covers (E-Bay Photo) The Covers are the only apparent changes to the 3 manuals-except the later 2 have a chapter at the back "How to add a second drive"
Disk Boot screen for Color Computer 1 Extended Basic	Disk Boot screen for Color Computer 2 Extended Basic	Disk Boot screen for Color Computer3 Extended Basic 2.1 with Microware credit

OS-9
Long before the Mac operating system came out. A company called Microware formed a partnership with Tandy to bring there OS-9 to the Color Computer. In 1983 Tandy introduced OS-9 to the world. Here finally was a "real OS", but you had to have 64K and a floppy drive to run it. Microware and OS 09 are still around and supported to this day. 23 years after the launch of OS-9, it still has a big user base. Microware even is still using OS-9 in Set top boxes and other applications today. I can think of no other OS (with the exception of UNIX) that is still so widely used and supported. Now most Color Computer users have "upgraded" to a CoCo 3 and use the newer nitrOS 09. This was built on top of the OS -9 level 2 code for the Color Computer 3.
The following is the actual description of OS 09 form the "Getting Started" manual. I am reproducing it because it sums up best what OS-9 is.
"OS-9 is a versatile operating system for the 64K TRS 80 Color Computer. It is based on the UNIX operating system developed by Bell Laboratories Inc. UNIX is widely used on larger computers especially in Colleges and Universities. OS-9 opens many new doors by expanding the Color Computer's Capabilities. OS-9 offers sophisticated features that are normally available in much larger computers. Among these are:
Multi Level Filing System
Like Most Operating Systems, OS-9 lets you store information on a disk in a "file" and index these files with a directory. OS-9, However, goes one step further by letting you create a hierarchy of directories and files.
Multiuser/Multitasking Operation
Multiuser means that more than one person can use the system at the same time. The number of users is limited to the number of terminals. The TRS-80 Color Computer can have one terminal; this means that two people can use OS-9 at the same time. One person one the Color Computer and one on the terminal.
Multitasking means that two or more tasks (programs) can run at the same time. For example, with OS-9 you can print reports and enter information at the same time.
Device-independent Input/Output System
OS-9 uses a very efficient method for imputing and outputting information. It expects all input to come form the "standard input device" and all the output go to the "standard output device". On the Color Computer, OS-9 expects all the input to come from the keyboard/console and all the output to got to the video display. You can easily "redirect" the standard I/O devices to other devices such as printers or disks. This means OS-9 program needs only one output routine and one input routine.From there you can redirect it to another device. This saves time for the programmer and space on the disk because programs can be shorter."

Getting Started with OS-9	OS-9 Program Development (Coil Bound Version)	OS-9 Commands (Coil Bound Version)
OS-9 Technical Information (Coil Bound Version)	OS-9 Level 2 for the Color Computer 3. This came in a nice binder and included a second binder with the Technical Guide	OS-9 Level 2 close up

nitrOS 9
The most recent update to OS-9 is called nitrOS 9. nitrOS-9 is an open source OS, that is constantly being developed. For more information click here to visit nitros9.org for all the latest updates and information. The OS is free to download, but you can order a copy from cloud9 if you wish.

(c) 2007 QuarkX.
 All Rights Reserved.