From: kr-lund@nogarbage.online.no   
      
   Larry wrote:   
      
   > "Knut Roll-Lund"  wrote in message   
   > news:QN6dnaXXCsrl_y7YRVnzvQ@telenor.com...   
   >   
   > snip...   
   >   
   >   
   >>how? Per side, it was normal to use 10 sectors of 256 bytes in single   
   >>density. In double density one would either have 18 sectors of 256 bytes   
   >>or 9 sectors of 512 bytes.   
   >>   
   >>Rich said 1 head. Single sided it is. 180K then makes sense only with   
   >>double density 40 track. It would be so on TRS-80 model I/III/4 and IBM PC   
   >>(with clones).   
   >   
   > snip   
   >   
   > 80-track single density = 180K is as close as I come using my TRS-80 Model I   
   > with 3.5" SD drives (720K when DDDS).   
   >   
      
   On my model-I I get   
      
   SSSD80: 256 bytes * 10 sectors * 80 tracks * 1 side = 204800 bytes (200K)   
      
   like   
      
   DSDD80: 256 bytes * 18 sectors * 80 tracks * 2 sides = 737280 bytes (720K)   
      
   With SSSD80 you are probably thinking of what is left after the DOS has   
   taken space for bootsector and dir, even more if DOS is there too.   
      
   --   
   Knut   
   (delete 'nogarbage.' for email)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)