TRS-80 Model III
Introduced in july 1980. 
It uses the Zilog Z80 CPU, and is priced from US$700 to US$2500. The Model 3 was Tandy's second personal computer it was somewhat better for new users because the monitor and keyboard were all in one unit. That got rid of the problems the Model 1 had with funky connections between the keyboard and expansion interface. The serial port was also usable. The cassette interface supported both the 500 baud speed of the Model 1, as well as a much faster 1500 baud. Using a cassette based system was much less painful with the data screaming along at that speed. 
The Model 3's BASIC ROM was 2k larger (at 14k) than the Model 1.
  • CPU; Zilog Z-80 
  • Ram 48K 
  • Disk Dual 5 1/4" drives 
  • Display 12" B/W monitor built-in, 64 chars/line 16 lines/screen
  • Catalog no. 26-1066
  • SN; 002677
Click here for a brief history of Radio Shack Computers.