RT-11 disk copying question

From: Jerome Fine <jhfine_at_idirect.com>
Date: Sun Feb 3 19:44:18 2002

>Tom Leffingwell wrote:

> I'm trying to copy one RX02 disk to another on my DSD-440 dual
> RX02 unit, with a 4.0 RT11XM system running on an 11/23. I first
> formatted the new floppy with FORMAT/VERIFY DY1:. It ran for a little
> while, and then verified for a little while. Next, I tried to do an
> INIT/BAD DY1:, hoping to write a directory the new disk. It reads my RT11
> disk in DY0:, and then asks if I'm sure, and then exits, without ever
> accessing DY1. If I do a DIR on DY1, it complains that the directory is
> missing, which makes sense since it never appeared to write it in the
> first place. I did notice that there is no INIT.SAV file on the OS disk,
> but I assume its an internal command if it goes as far as asking me a
> question.

(a) If you are going to FORMAT DY1:, then don't bother with the /VERIFY
switch - keep things simple. Note that you can't actually do a "from scratch"
LLF (Low Level Format) FORMAT under RT-11. All that actually does is
change the density. The LLF must be mostly OK first. Also, DO NOT
confuse FORMAT on RT-11 with FORMAT on DOS/W95/W98. For a
PC, FORMAT also does the INIT plus often places SYS files and other
such stuff. In RT-11, a FORMAT basically means just the LLF, except when
it does not - like with the RX02. The DSD 440 will do a real LLF off-line
by setting a dip switch - I can't remember which one or the setting. You
turn off the power, set the dip switch and turn the power back on. The
DSD 440 does a format after which you can repeat the process - I think?

(b) The INIT command in RT-11 sets up a file structure - ONLY the file
structure - this is the optional volume name and owner in the second block
of the device (Block One) and the first EMPTY fire directory segment in
blocks 6 and 7. Note that since an empty file structure is only 13 words
long (for a beginner that is sufficient information), only block 6 is changed.
The utility used is DUP.SAV (Device Utility Program I guess). If you
want to check the floppy after that, use "DIR DY1:/BAD" which is almost
useless, so I would not bother - there are much better ways - none very
good in V4.00 of RT-11.

(c) If you are trying to produce an exact "block for block" copy of DY0:
into DY1:, then use:
COPY/DEVICE DY0: DY1:
and the file structure is ignored. A block for block copy is made. If you
have any BAD blocks on DY0: or DY1:, it probably will not work.

(d) COPY DY0: DY1: does a copy file by file (/SYS will also include
system files)

(e) After just a COPY, you must do:
COPY/BOOT DY1:RT11XM.SYS DY1:
to set up the boot programs on DY1: whereas with COPY/DEVICE, all the
blocks are copied, including the boot blocks (0,2,3,4,5).

Any other questions?
Received on Sun Feb 03 2002 - 19:44:18 GMT

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