OK, I've got a wierd question now. What is the lifespan of Magnetic Media?
In this case, I'm concerned about 4mm DAT, but since I'm more familiar with
8mm it as an example.
Let's say I've got a stack of 8mm tapes with data on them. They're
supposed to be good for archival purposes, when stored in the proper
conditions for 2 years.
Now let's say I've got a brand new box of 8mm tapes that have been sitting
around still sealed for 8 years. Again, they've been stored in the proper
conditions more or less. So are they still good? Is the 2 year number for
their ability to hold data, or the actual physical lifespan. Anyone have
any ideas?
The real reason for the question is finding some 4mm tapes that are still
sealed, and I'd estimate about 8 years old.
Zane
| Zane H. Healy | UNIX Systems Adminstrator |
| healyzh(a)aracnet.com (primary) | Linux Enthusiast |
| healyzh(a)holonet.net (alternate) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
On Mar 30, 15:25, healyzh(a)aracnet.com wrote:
> > I think the 2 year is for reasonable useage.
>
> Actually the 2 year number is from a government study that I don't
believe
> is still online :^( It was refering to writing the data to tape and then
> sticking the tape in a vault. In other words an archive tape. They
found
> 8mm was good for 2 years, while DLT and 9-Track tapes were good for 10
> years.
>
> > New tapes should last for 30 to 40 years at least
> > with good storage. Tapes with data may not fare as well.
That seems logical to me. I wonder how much of the apparent data loss is
due to print-through? I was told that tapes ought to be rewound every year
or two to minimise the print-through effect. The idea is that by doing so,
you change the overlap between layers on the spool, and the effects cancel
out to some extent.
Having said that, I've just been reading some old cassette tapes on my
Exidy Sorcerer. I sold my original Sorcerer (and associated tapes) 20
years ago, but got a replacement (with no tapes at all) for my collection
recently. Last weekend, a friend brought me some tapes he'd found from
his, unused since 1980. I've managed to read every program I've tried so
far -- about a dozen -- on the four tapes I've tried. In a couple of
cases, I got errors on the first read, but no problem on the second. I
think that's probably due to the tape being more evenly wound/tensioned
after playing through and rewinding once, a common effect in compact
cassettes as I recall.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
On March 29, Technoid(a)cheta.net wrote:
> I have tried the 'n' command and it says it is not a command. If I enter
> "new" it responds "cpu cache enabled" which is not what I wanted at all.
> Is it possible this Sparcstation 330 (sparc 4/300) does not have the 'new'
> prompt at all? --
Nope...of all the models in the sun4/xxx family, only the 4/6xx has
OpenFirmware. The 4/1xx, 4/2xx, 4/3xx, and 4/4xx have sun3-style "old
mode" only.
-Dave McGuire
Bill and I spent the morning sorting through the Altos stuff we
had rescued, and this is what we think we have:
Altos 5 Box, Z-80 CPU, bunch of serial ports, two 5.25" floppy drives.
Also a binder full of Altos 5 documentation.
Altos 8000 Boxes (2 of them), Z-80 CPU's, bunch of serial ports, 8"
floppy drives, and a binder full of accompanying documentation.
Altos 68000 Boxes (3 of them), 68000 CPU's, one of the boxes has an
expansion board filled with RAM, two of the boxes have 8" hard drives,
all of the boxes have an 8" floppy drive, one of the boxes is missing
the panel on the back filled with serial ports.
We also have lots of Altos 8" software distribution floppies.
Condition is unknown. Some of the boxes have stickers from ten years
ago indicating that they were (at least partly) functioning back then,
but we haven't powered any of this stuff on.
Anyone interested? We will consider shipping these to a good home, though
we'd prefer to find local (Washington DC area) takers. You don't
have to take them all, you can pick and choose if you wish.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
Whilst digging out some 380Z manuals I found a "Prime 2455" I'd forgotten I
had....
I'd like to have a bash at getting this going, but aside from needing OS
tapes (anyone help PLEASE?) the tape drive and hard drive have been removed
along with some sort of drive mounting tray.
Can anyone tell me what types/capacities of hard drive I can fit to this
machine, and what model of tape drive does it take (all I know is that the
tape and hard drives are SCSI devices)?
Also, I *NEED* the mounting tray/stage which fits inside the top of the
machine to which the drives attach. Anyone in the UK in a position to help?
TTFN - Pete.
--
Hardware & Software Engineer. Sound Engineer.
Collector of Arcade Machines, Games Consoles & Obsolete Computers (esp DEC)
peter.pachla(a)wintermute.org.uk | www.wintermute.org.uk
--
On Mar 30, 22:30, Olminkhof wrote:
> I do this and get:
>
> 147470
> @
>
> Further iterations all result in:
>
> 173000
> @
>
> If I hit restart at any time after that there is a some disk activity and
> eventually and "&" prompt appears.
The first address is in RAM, which is interesting. It suggests the
processor is executing some bootstrap that gets copied into memory. 173000
is the standard bootstrap address; every time you restart the CPU, it sets
the program counter to that address. The "&" is not any normal PDP-11
prompt, so that must have come from the disk or custom boot roms.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
On Mar 30, 19:25, Philip.Belben(a)powertech.co.uk wrote:
> This is only on topic at all because I shall be using a classic computer
for
> it...
>
> I understand that some mobile telephones nowadays can download tunes to
play
> when they ring. Can anybody point me to (a) the download protocol(s)
that the
> phones use and (b) the file format(s) for these tunes?
Yes, several Nokia, Ericsson, and Siemens models can download tunes, and a
few can be programmed in other ways with a data cable. One place to start
might be
http://www.cellulartips.com/index.html
but there are lots of other sites around. You'll find a lot of information
by using AltaVista, or DejaNews to search the uk.telecom newgroups as well
(look for "nokia" and "data"), eg
http://www.gadgets.demon.co.uk/nokia61xx/
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
This is only on topic at all because I shall be using a classic computer for
it...
I understand that some mobile telephones nowadays can download tunes to play
when they ring. Can anybody point me to (a) the download protocol(s) that the
phones use and (b) the file format(s) for these tunes?
Philip.
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> realise there was an analogue I/O card for the 380Z. I've got no
> info on the winchester and network cards, but I guessed they must
> have existed. IIRC at least one of the RML winchester systems was a
> box about the size of a 380Z with a PSU, ST506-interfaced drive and
> a SASI-ST506 interface card. I assume the 380Z interface was a SASI
> host adapter or something.
The 3rd. party winchester disk unit measures 16" x 16" x 4.5" and the
cover (top and sides) is a beige type plastic with rounded corners
(radius about 1") on the top of the sides; sitting on a metal base/
font/back. It has the wiring for two 5.25" FH disk drives but contains
only one Rodime RO 100 (4 platters/8 heads/192 cylinders). The
interface card in the disk unit is a 'Konan David Jr. II'. As I
mentioned this has never worked. The instructions for running up
the hard disk (given verbally to me) was to insert the floppy
containing the executable x and to type x - Found the floppy,
typed the command - nothing, although the disk does whirr quite
happily, it doesn't seek.
> I'd always assumed that the IEEE-488 card was a card that connected
> to the bus cable. Are you saying that it's a daughterboard that
> fits under the Z80 or something?
The 3.5" square (exactly) daughter board plugs directly into and
only into where the Z80 CPU normally resides. The board contains:
Z80 CPU, AM25LS252IPC, 2 x SN74LS245N, SN74LS00N, 74F32PC chips
with assorted resistors etc. There is a 26 way berg connector to
take the cable to the IEEE-488 port. Also there is a 8-way link
box with 5 unbroken links, 2 broken links and 1 remade link.
> Do you happen to have schematics other than the ones that appear in
> the normal Information File.
Sorry, no schematics
Doug.
Since alt.sys.pdp10 is in a big flamewar right now, I guess I'll ask here.
Does anyone know the correct geomerty of an RP04 pack in 18-bit mode?
I have it as 19 heads, 411 cylinders, and 20 sectors a track, with 260
word sectors. (18 bit words, 256 data words and 4 header words.)
I think that's wrong though.
-------
