8 Aug
2001
8 Aug
'01
11:17 a.m.
On Aug 8, 21:41, SP wrote:
Some days ago I send an inquiry about the way to
format one
RD52 Hard Disk attached to one DILOG DQ614 board.
The unique obscure matter is this: the RD52 (in my case) must
be jumpered like DS0. I reviewed the disk and it only has the
jumpers: 'DS1', 'DS2', 'DS3' (this is actually selected),
'DS4'
and 'A'.
Older floppies and MFM hard disks enjoyed two numbering schemes: some
people labelled the four drive select lines as DS0 - DS3, while some people
labelled them as DS1 - DS4. If your documentation refers to DS0 but your
drive is labelled with DS1 - DS4, you just use DS1 instead. DEC's
RXDX1/2/3 controllers normally used DS3 (in the DS1 - DS4 scheme) for all
hard drives, and re-routed the signals on a distribution card to select the
appropriate drive. This allowed you to move drives around without changing
the links, much like IBM arranged all drives to use DS1 and a twist in the
cable.
Finally, I must appoint that RT-11 and Unix detect
that exists
at least one DL0 and one DL1 in the system, but they can't access
the 'bad sector info'. In the case of the DL1, Unix BSD2.11 ask me
for the 'CSR'. What is this, Gurus :-) ?
CSR = Control and Status Register, which is normally mapped into memory at
address 774400(octal) for the first RL(V)11 in a system.
--
Pete Peter Turnbull
Network Manager
University of York