Many of us maintain large collections of bits that we'd like to preserve over a long time, and distribute, replicate, and migrate via unreliable storage media and networks. As disk sizes (and archive sizes) have increased, the probability of corruption undetected or uncorrected by the mechanisms normally built into disk drives, network protocols, and filesystems has increased to a level that warrants great concern.
I would be interested to know if there exists an archive format that has the …
[View More]following desirable properties:
1) It is well-documented, and relatively simple, to facilitate its implementation on many platforms present and future.
2) It supports some degree of incremental updating, but need not be particularly efficient about it. An explicit compaction operation is preferable to an overly complex format. It is adequate to use append-only strategies appropriate for write-once media.
3) Insertion and extraction of files, copying of the archives, and other archive-manipulation utilities support end-to-end verification that identical bits have been stably recorded to the media, bypassing or defeating platform-level or hardware-level caching mechanisms. Where this is not possible, the limits must be carefully delineated, with some basis for determining the properties of the platform and certifying reliability
properties where possible.
4) The format should provide for superior error detection capability, designed to avoid common failure modes with mechanisms typically used in hardware. For example, use a document-level cryptographic checksum rather than a block-level CRC.
5) The format should include a high degree of internal redundancy and recoverability, say, along the lines of a virtual RAID-array.
Just as biological organisms constantly correct DNA transcription errors,
the idea is to have a format that is robust across long-term exposure to
imperfect copying and transmission channels.
Does anything like this exist?
--Bill
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I too have been searching for documentation/schematics for the Cambridge
Memories, Inc. Expandacore18 4k core memory boards. I have an old
Diversified Numeric Applications Med PL/185 machine which is a clone of the
Raytheon 703. This machine has 16k of core with 4 of these boards.
--
THE BLUES IS THE TRUTH. IF IT'S NOT THE TRUTH, IT'S NOT THE BLUES. (Willie
Dixon)
Here is an interesting article from the ozobob list on 50 yeas of
computing in the US Army!
http://www.dtic.mil/get-tr-doc/pdf?AD=ADA431730
About the earliest thing we have militantly computer related in the
museum are some parts of the NORAD SAGE system
(Apologies if this gets posted twice, e-mail changes appear to have lost
the first one...)
Hi all --
Just wanted to let you guys know that a new version of the Xerox Alto
emulator I've been working on at the LCM+L has been released. V1.1 of
ContrAlto can be downloaded from:
http://www.livingcomputers.org/Join/Online-Systems.aspx. At this point,
the vast majority of software appears to be working properly, if you do run
into any issues please let me know!
ContrAlto is open source, so if you …
[View More]want to hack on it the source is
available on our GitHub site at
https://github.com/livingcomputermuseum/ContrAlto.
Thanks!
- Josh
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I have pmaz SCSI controller, a couple lofis, and a bunch of 8MB pmax+
modules that are being threatened with the local electronics recycler.
send me the address of your good home or place of business in the
continental US states, and I'll spare them that fate.
--
Aaron J. Grier | "Not your ordinary poofy goof." | agrier at poofygoof.com
I scanned my copy of the Hitachi 303 manual a few weeks ago. For anyone
interested in downloading it, I uploaded it here:
https://drive.google.com/open?id=0B8Ow1Wo1rBQUSVdXQU84SWtVRFU
Didn't see it on Bitsavers yet, so I thought I would share.
Thanks,
Kyle
I have not had good luck with the RuGRiD list. I am aware of it.
There are only a small handful of people there with Compass gear; It is
mostly centered around the later PC-compatible GRiD stuff.
There is one fellow with quite a lot of Compass media who has reached out
to me a couple times, but I don't get the drift he sees any urgency in
imaging the media, nor intends to share it. I have offered a hand, money,
etc.
If he does come through, I'll be very pleased, but at this point I am
trying …
[View More]to look elsewhere.
Steve, if you're willing to cross-post my list below and see if you have
better luck, please do.
I have never received a single response of value on that list.
- Ian
On Tuesday, October 25, 2016, Steve Hatle <shatle at nfldinet.com
<javascript:_e(%7B%7D,'cvml','shatle at nfldinet.com');>> wrote:
>
>
>
> -------- Original Message --------
> Subject: Need to archive: GRiD Compass Computer Operating System
> Software
> From: Ian Finder <ian.finder at gmail.com>
> Date: Tue, October 25, 2016 7:08 pm
> To: "cctalk at classiccmp.org" <cctalk at classiccmp.org>
>
> Folks, there appears to be a large GRiD-sized hole where archived copies
> of
> the Compass Computer Operating System software should be.
>
> ...
> --
> Ian Finder
> (206) 395-MIPS
> ian.finder at gmail.com
>
> >>
>
> There's a fairly active GRiD list at
>
> http://groups.yahoo.com/group/rugrid-laptop/
>
> You may wish to cross-post there, or I can if you don't wish to join up.
>
> Steve
>
--
Ian Finder
(206) 395-MIPS
ian.finder at gmail.com
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I picked up an Informer 213 from eBay this week, but it has the IBM rom
set! Noooooo!
Anyone out there with the VT100 version willing to dump the roms for me?
Thanks,
- Ian
--
Ian Finder
(206) 395-MIPS
ian.finder at gmail.com
> From: allison
> What vendor
I don't recall, would have to look it up; I turned Guy onto them, and he
bought out everything they in stock.
> They have been scarce save though resellers that have NOS parts from
> old stocks and they are not cheap and unpredictable quantities.
Yeah, that vendor said they could get more (apparently from others who still
had stocks), but they'd be slightly more expensive. Apparently these people
all interact, and deal stuff around.
So …
[View More]that figure I was given of 30K in stock is probably not from that one
vendor, but across all of them. But since nobody is using these chips in a
product (that I know of), I suspect the number is likely to go down only
slowly.
> Then I could buy them they are about .86 dollar US, but that was in the
> early 80s.
The ones Guy and I recently bought were about $1 each (I don't recall the
exact amount, would have to check). So not cheap, but not ridiculous.
Noel
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