Tandy CoCo Basic
  
Models of the Tandy TRS-80 Color Computer 1, 2, and 3 


Model                                  
RAM as sold
RAM
Upgradeable
# RAM
Chips
Installed
BASIC Type          
BASIC
Upgradeable
Keyboard                   
    
CoCo 1 - CPU 6809E 8-bit @ 0.894 MHz.
TRS-80 CoCo 1 model 26-3001  (Jul 1980)
4K         
                     
               
Color BASIC 1.0                    
                      
"chicklet" keyboard        
TRS-80 CoCo 1 model 26-3002  (Sep 1980)
16K        
                     
               
                                   
                      
"chicklet" keyboard        
TRS-80 CoCo 1 model 26-3002A           
16K        
                     
               
                                   
                      
"chicklet" keyboard        
TRS-80 CoCo 1 model 26-3003     (1982) 
32K        
                     
               
                                   
                      
"chicklet" keyboard        
TRS-80 CoCo 1 model 26-3003B           
64K        
                     
               
                                   
                      
"melted keyboard        
CoCo 2 - CPU 6809E 8-bit @ 0.894 MHz.
TRS-80 CoCo 2 model 26-3026  (Sep 1983)
16K        
Yes to 64K           
8              
Standard Color BASIC               
YES                   
CoCo 2 Standard Keyboard
TRS-80 CoCo 2 model 26-3026A           
16K        
Yes to 64K           
8              
Standard Color BASIC               
YES                   
CoCo 2 Standard Keyboard 
TRS-80 CoCo 2 model 26-3026B           
16K        
Yes to 64K           
8              
Standard Color BASIC               
YES                   
CoCo 2 Standard Keyboard
TRS-80 CoCo 2 model 26-3027            
16K        
Yes to 64K           
8              
Extended Color BASIC      
YES                   
CoCo 2 Standard Keyboard
TRS-80 CoCo 2 model 26-3003 (1983)     
64K        
No                   
               
Extended Color BASIC      
                      

TRS-80 CoCo 2 model 26-3134B           
16K        
No                   
               
Standard Color BASIC               
                      

TRS-80 CoCo 2 model 26-3136B           
32K        
No                   
               
Extended Color BASIC      
                      

TRS-80 CoCo 2 model 26-3127B           
64K        
No                   
               
Extended Color BASIC      
                      
'enhanced' keyboard
CoCo 3 - CPU 6809E 8-bit @ 1.788 MHz.
TRS-80 CoCo 3 model 26-3334     (1986) 
128K       
Yes to 512K          
1 board        
Super Extended Color BASIC
                      
'enhanced' keyboard


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Extended Color BASIC

Extended Color BASIC (ECB) 1.1 and 1.3 are ROM versions for the 
Tandy TRS-80 Color Computer (CoCo). 

Version 1.3 was released to 
  resolve bugs found in 1.1, 
  improve the efficiency of the interpreter, 
  and better support the hardware updates found in later CoCo 2 models. 

Key Differences:

Version 1.1: Commonly found on earlier CoCo 2 models, offering foundational 
Extended Color BASIC features (graphics commands, drawing, editing).

Version 1.3: A matured version focusing on stability, with minor refinements to 
the BASIC interpreter's handling of code, commonly used in later, more 
cost-efficient CoCo 2 models (e.g., 26-3026A/B). 

----

Upgrading a Tandy Color Computer 2 (CoCo 2) 

The Three most common:

Memory Upgrade
This involves increasing RAM from 16K to 64K, 
  4517/4416 RAM chips with 4164 DRAMs, 
  setting jumpers to enable 64K (usually J1/JP1), 
  and installing an EPROM for ROM upgrades


BASIC Upgrade
installing Extended Color Basic, 
   Extended Color Basic: If your machine lacks it, 
   replace the ROM with a 27128 EPROM containing both 
   Color Basic and Extended Color Basic.


Video Upgrade
Adding composite video output.