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
Received on Wed Aug 08 2001 - 15:17:40 BST