XPost: comp.sys.sinclair, comp.sys.atari.8bit, comp.sys.apple2   
   XPost: comp.sys.cbm   
   From: nobody@nowhere.com   
      
   "Michael J. Mahon"  wrote in message   
   news:GrWdnfXaiY45NCjenZ2dnUVZ_tydnZ2d@comcast.com...   
      
   > In the case of the Apple II, the (somewhat unusual) layout of display   
   > memory was a consequence of using the video refresh to accomplish the   
   > refresh of the DRAMs.   
   >   
   > The result is that no special refresh circuitry is used, and, since   
   > all video accesses occur on the alternate half-cycles not used by   
   > the processor, there is never any interference with the processor   
   > for video or DRAM refresh.   
   >   
   > A little cleverness simplifies a lot.   
      
   Woz was the man!   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)