XPost: comp.sys.cbm   
   From: markm@vl.com.au   
      
   a7yvm109gf5d1@netzero.com wrote:   
      
   > http://en.wikipedia.org/wiki/TV_Typewriter   
      
   "The ingenious part of the design was the way Lancaster ‘tricked’ the   
   microprocessor into acting as the CRT Controller (to save on costs and   
   complexity). Basically, a TV sync generator generated an interrupt that   
   dropped the 6502 into a routine that emitted a series of NOPs starting   
   at a convenient address. Those addresses were used to access display   
   memory."   
      
   Interesting, AFAIK the Sinclair ZX80/81 uses the same technique.   
      
   Regards,   
      
   --   
   Mark McDougall, Engineer   
   Virtual Logic Pty Ltd,    
   21-25 King St, Rockdale, 2216   
   Ph: +612-9599-3255 Fax: +612-9599-3266   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)