Date   : Wed, 07 Jan 1998 13:47:12 +0100
From   : "Mark Usher" <marku@...>
Subject: Advanced Hard Disc problem.....

Hi guys,

Hmmm. Maybe someone can shed a little light, or at least it will give Dr
David A G.  the chance to chew on some chocolate :-)

OK, I have a SCSI HD connected to the BBC via the SASI host adapter.
The problem is at a very low level.
Writing
?&FC40=&1
?&FC42=&0
Will select the drive on the bus. No problem.
Then when I pass *any* command to the drive eg. format &4
?&FC40=&4
followed by it's 5 parameters
?&FC40= ......
It returns after receiving 3 bytes (command & the first 2 parameters) saying
that the drive wants to output.
It then outputs byte &2 followed by &0
This is the same for 10byte commands also, it wants to output after
receiving the first 3 bytes.

If I change the initial
?&FC40=&1
?&FC42=&0
to
?&FC40=&81
?&FC42=&0
Then the drive returns after accepting five bytes, regardless of the command
being a 6 or 10 byte'r.

Now there are some interesting results.
When ?&FC40=&81 / &41 / &21 then it accepts five bytes otherwise it only
accepts 3.

Anyone have any ideas ?

Mark Usher
marku@...