8c5fe7e2   
   From: joe@user.com   
      
   "N Morrison"  wrote in message   
   news:b8229659-6728-4240-8ad3-da14afe824cb@b14g2000yqd.googlegroups.com...   
   >On Jun 30, 5:14 pm, Ira  wrote:   
   >> There has been a recent uptick in people getting TRS-80's only to find   
   >> out that the disk drives do not work AFTER getting diskettes.   
   >>   
   >> Does anyone know how to get as good a gauge as to whether the floppy   
   >> drive works or not, short of having a boot disk? This applies to Model   
   >> I and III/4.   
   >   
   >There was a catseye disk which read out the drive condition on screen.   
   >Expensive when new - and I saw one once on eBay - mucho bucks.   
   >   
   >You can't copy the disk - they're made on special 'wobbling' hardware!   
   >   
   >I imagine you could write a program that gave basic information on   
   >similar lines - don't recall ever seeing such a thing.   
      
   At one point there was even a 'bootable' disk that had the cats-eye pattern   
   on it.  You could even do it with 'tricks' and have the cats-eye be readable   
   data and the program will then let you align from the screen instead of with   
   an oscilloscope.  Tandy sold the disk through their National Parts at one   
   time.   
      
   And you're right, they have to have the 'alignment track' put on with a   
   'wobble'.  And the wobble has to be 'set' against the index pulse.  (Well,   
   on the scope version)   
      
   But you can do an alignment without the cats-eye, if you're careful.  If   
   you have a KNOWN good diskette, you can just 'center' the track.  Set   
   up a program to read all the sequential sectors on a track and throw the   
   data away.  Take the drive out of alignment slowly in one direction until   
   it fails.  Then return and go out of alignment the other direction.  Do this   
   a number of time and then set the alignment to the midpoint between the   
   two failures.  You'll be fairly close.  Not as good as a cats-eye, but   
   usually close enough.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)