ZX Power #02 24 мая 1997

TR-DOS

Likbez - Fighting controllers, or about how I played the 800K floppy.

(C) Cobra
________________________________


   All sinkleristam that
pumped files from computers
IBM clone known so-called problem of 800K floppy disks - to ZX
when read always occurs unfortunate error: disk
error tr xx sec 10, and as offensive
happens when, after so many torments refuses to read the 
information extracted, and all because of the fact that the 
disk has been formatted not at 720 k and at 800K, and,

interestno that:

      1.If the drive was formatted
     Rowan on the Spectrum, the nick
     FIR problems with reading are not

     there!

      2.When reading IBM compatible
     mymi computers sinkle
     Cooper floppy disks, which

     pre-formatted
     Wali in TR-DOS, also arises
     Cabins errors of a different character
     character - not read first
     vy sector on the track!? But

     If the drive is otrestavri
     synchronize, for example, in the RDS, then

     no problems no longer

     there ...


   Let us see why this
prishodit.Posle analysis program RDS has learned that our
ill-fated sector, one that is under
number 10, has the label + +? And
This means the following - a title
sector is, the sector itself is, but
here's the problem - it does not end
Checksum sector no!

   Hmmm, interestno ... Further,
read the track with our drive team read track, I found
most interestnoe - our favorite
sector does not end at all!
After reading it to half, the team
read track interrupts their work.

   It is known that the team read
track starts reading with the advent
index pulse (when
hole in the floppy disk coincides with
hole in an envelope disc)
reads the entire track, and on arrival
next index clock stops reading. Consequently, the clock pulse 
arrives at a time when the sector is read ... And obviously, 
the controller generates an error at this point

read ... And here arises
trivial solution - seal the index hole at all! Just
take and seal to the controller does not know when it comes to 
index sync! 

   R A B O T A T E! ! !

   CDs are read excellently!

   And the whole business it was - sinklerovsky controller is 
synchronized to the top of the index, and IBM-ovsky - at the 
end! Hence the all the trouble. There is a slight bias in the 
results of which Sinclair did not read the last sector, and IBM 
- the first (it is known that TR-DOS creates the first sector 
is indented from the start tracks less than disc

utilities, such as RDS ...).

   So we can safely say
that one problemma Sinclair
fewer - here I am, until stuffing the text, listening to MOD-uk
which is loaded with this here
Disk ...

   In continuing its consideration of
questions about the mysteries of TR-DOS like
appeal to readers: if anyone
know some details of
Life TR-DOS, for example, why
read track team, in some cases do not stop reading
even the arrival of the index sync, please write in
HQ version of the address listed in the section titled Authors.
________________________________