Date   : Sun, 10 Dec 2006 06:27:28 -0600
From   : julesrichardsonuk@... (Jules Richardson)
Subject: unable to save to disc

Chris Johns wrote:
> On Sat, 9 Dec 2006, salahdin mahmud wrote:
> 
>> A friend has an american import of the bbc. Seems to work with drive eg
>> loads ok, but won't save. He tried formatting, still won't work and reports
>> 'verify error' at track 0 on formatting. Drive is definitely ok and so is
>> dfs rom.
> 
> Could be it's not actually writing anything to the disc at all. 

I wondered that, too. It may be that either the 'write gate' or 'write data' 
lines to the drive aren't working for some reason; for read operations 'write 
gate' will be inactive (at +5V) and 'write data' obviously doesn't get used.

Possible culprits:

   Faulty FDC chip
   Dirty FDC chip pins
   Short on the PCB due to debris / damage
   Faulty cable (shorted pins tying write lines to a particular logic level, 
or broken connection resulting in write gate floating high - and hence 
permanently inactive - within the drive)


If your friend has a multimeter then get him to do some poking around when 
writing to a disk - write data is pin 22 on the drive and write gate is pin 
24. If he doesn't, then he can at least do a visual check on the PCB and 
re-seat the FDC chip (cleaning contacts too)

Of course all of this might be a software issue - but from a software point of 
view I would have thought that if a disk reads OK then writing should work too.

cheers

Jules

-- 
there's a carp in the tub
there's a carp in the tub
so nobody's taken a bath