>I dont know RT-11 (yet.) and am looking forward to the experience. But
>before that happens the seller wants to purge some sensitive employee
>files on the system. Can someone tell me how to tell him to 1) move
>through the directory structure, and 2) how to delete specific files (
>some that span partitions 0 - du4 according to him ), and...
On RT-11, as with many OSes, deletion of a file simply updates the
directory in some way to indicate that the file is deleted. In some OSes,
it might mean removal of the directory entry which pointed to the data on
disk (or the list of pointers to retrieve the info). In some, it may be
to mark the directory entry as a deleted file.
In the case of RT-11, it marks the disk space taken up by the file to be
'free'. But until another file is written over that data, it remains,
and can be retrieved.
What they can do, however, is to delete all those files which they don't
want anyone to have access to, and then to 'SQUEEZE' the disk volume.
The squeeze process is similar to what Windoze does when it defragments
a disk volume, only RT-11 files are not fragmented - they exist as
contiguous files. But the files are all moved to the beginning of the
disk (low block numbers) with all the free space consolidated to the
end of the disk (higher block numbers). This will result in at least
those deleted files which existed between others being overwritten
with files being moved. The only problem might be a deleted file at
the end of the volume (or if the quantity of deleted files are sufficient
that the moved files don't adequately cover the deleted ones). It
should be possible to write a very short program which will determine
the last block used on the (squeezed) volume, and to write null blocks
to all disk blocks from there to the end of the volume.
Finally, RT-11 files cannot span RT-11 disk partitions. An RT-11
file can only exist in the partition in which it is defined. It is
possible, however, for a user application to make use of the system
library routines which allow full access to an MSCP disk -- in which
case doing the squeeze won't help.
What you may want to suggest to him is to
1) Delete all sensitive files from all disk partitions
2) Squeeze all disk partitions.
3) backup all disk partitions (on a file, not device, basis)
4) FORMAT all disk partitions (RT-11 Format doesn't really
do a low-level format except for specific devices, and
MSCP disks are not one that it will do -- with the
exception of RX33 diskettes)
5) Restore the backed-up files to all partitions.
6) Release the hardware to you... :-)
>Where can I find a good source of RT-11 info?
Not counting the documentation which can be purchased for it...
right here is a good place... :-)
Megan Gentry
Former RT-11 Developer
+--------------------------------+-------------------------------------+
| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
| Unix Support Engineering Group | (home): mbg!world.std.com |
| Compaq Computer Corporation | addresses need '@' in place of '!' |
| 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ |
| Nashua, NH 03062 | "pdp-11 programmer - some assembler |
| (603) 884 1055 | required." - mbg |
+--------------------------------+-------------------------------------+
I have hard back copy of VAX-11 Assembly Language Programming written by
Sara Baase and published by Prentice Hall. If anyone wants it, E-mail me
directly.
Joe
On Jan 16, 10:42, George Rachor wrote:
> Subject: Apricot F10
> Spotted a curious find last night...
>
> It was labeled Apricot F10.
>
> It was narrow and had a minidisk slot in the front. In the back it had
> what looked like a rca jack (Video?), a parallel port (Centronics) a nine
> pin(serial) and something like a DB25.
>
> I suspect this is an expansion unit for the apricot line as I saw no
> obvious keyboard port unless it was the DB-25...
I don't think it's an expansion unit; I'm pretty sure it's a complete
computer, except that it's not complete in this case :-) It sounds very
like an F1, so perhaps the connections are similar.
On the back of an F1, there's a 25-pin D serial port, a 9-pin D colour
monitor connector, an RCA jack mono (composite video) monitor socket,
centronics parallel port on the bottom, and a pair of power connectors
higher up. The main power socket is an IEC style, and there's a 12V power
input for use with an Apricot mono monitor as well. The keyboard
connection on an F1 is by an infrared link. There's an IR sensor on the
front, and a fibre optic connector as well, for situations where the
sensor picks up too much interference.
Perhaps the F10 also has an unusual keyboard connection on the front?
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Possibly. I still don't like to endorse a company that built a computer
that the display exploded in my face (sort of - it shattered and started
leaking LCD juice everywhere-during use). It was new. The model line only
lasted about 6 months.
The best bet would probably include a computer in a tower case, with a
flat-panel display, eliminating the hazards of the pressure in a CRT.
--
-Jason Willgruber
(roblwill(a)usaor.net)
ICQ#: 1730318
<http://members.tripod.com/general_1>
-----Original Message-----
From: Russ Blakeman <rhblake(a)bigfoot.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Sunday, January 17, 1999 3:36 PM
Subject: Re: Disasters and Recovery
>While gateways, Dells, GRiDs and others would be good, I have a 4 yr old
Toshi
>that's never needed more than a battery and it's seen some rough use. It
may be
>that you've gotten a blemish or a used one that was treated badly before
you got
>it.
>
Just a though:
Build a computer with 2 CD-ROMs, a hard disk, and a floppy (and whatever
else you decide to throw in there - maybe even a DVD). Configure one of the
CD-ROMS as the primary master, and the HD as the primary slave. Write the
OS/boot files to a CD/R disk, and have it boot of the CD-ROM (provided that
the CD-ROM drive will still spin up. And surely, a CD-ROM drive would be
much easier to repair than hard disk, and no alignment would be necessary,
thus eliminating another problem.
Another solution may be to deep-freeze the whole mess, and put it into
"suspended animation". I'm not sure how it would work with magnetic media
or bearings / lubricants, but it does wonders with rubber. My grandmother
had a rubber band from 1956 (around that time) in her freezer holding a
cover on a fruitcake (no joke). Last year she finally decided to trash the
fruitcake. She let it thaw (to keep the container), and when the rubber
band had defrosted, it was as pliable and stretchy as if it had been brand
new (to a point).
Of course, you would need to leave specific instructions on how to defrost
the system, leaving it in a climate-controlled room, slowly raising the
temperature degree-by degree, as to not have any disasters, such as the CRT
imploding from sudden temp changes. Better yet, throw in a flat-panel LCD
display. Near the end of 1999, they should be a bit more affordable.
--
-Jason Willgruber
(roblwill(a)usaor.net)
ICQ#: 1730318
<http://members.tripod.com/general_1>
On Jan 17, 8:12, Cameron Kaiser wrote:
> Subject: Re: OT? On Programming (was: Re: Computers for children)
> ::> I'd hate to hear what you have to say about Elm, which is my
favourite
> ::> mailer. :-)
> ::
> ::Mine too. But it badly needs to be updated to support metamail and
mime
> ::message creation from within elm and support stuff like pgp.
>
> Actually, it does. PL25 ME39 (which comes in the Debian dist, ask me for
the
> tarball) supports in-process attachments and PGP. And PL25, which is
> commonly available, supports MIME through metamail.
I've had almost zero exposure to elm, so I'm not in much of a position to
comment -- not that that always stops me :-)
I'd guess elm (which is what pine was originally based on) is smaller,
sleeker, and simpler. Not a bad thing...
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
If you want something to last 100 years, DONT't leave a Toshiba. I've got
one, and it won't even last one year without breaking. I've had it for
three years, and it's been in the repair shop 10 times, all because of
product defects.
The best would probably be one of the new Gateway laptops (can't remember
the model). It also has a magnesium housing.
--
-Jason Willgruber
(roblwill(a)usaor.net)
ICQ#: 1730318
<http://members.tripod.com/general_1>
Ya know - the people at GRiD seem to have had a good idea about the
magnesium casing...It just didn't catch on quick enough.
-----Original Message-----
From: Doug <doug(a)blinkenlights.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Sunday, January 17, 1999 1:49 PM
Subject: Re: Disasters and Recovery
>On Sun, 17 Jan 1999, Chuck McManis wrote:
>
>> One of the reasons I want to have a completely spec'd Pentium class
>> computer is to create an archive that will survive a reasonable amount of
>> time (100 years in a time capsule).
>
>Don't leave them a clunky desktop box, leave them something like a sleek
>Toshiba Portege 3010 (3lb notebook in magnesium case) along with a solar
>cell so they can fire the thing up when they pull it out of the capsule.
>
>Remove all batteries, of course.
>
>-- Doug
>
>
