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 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
----- Original Message -----
> Date: Sun, 22 May 2011 22:56:32 -0500
> From: Daniel Seagraves <dseagrav at lunar-tokyo.net>
> Subject: Re: Scraping DEC Equipment
> To: "General Discussion: On-Topic and Off-Topic Posts"
> <cctalk at classiccmp.org>
> Message-ID: <C7A98127-DFF4-41B1-A6AF-5DFCA234D286 at lunar-tokyo.net>
> Content-Type: text/plain; charset=us-ascii
>
> I need a tractor feed assembly for a LA100, are the ones on the 120
> compatible?
----- Reply:
Apparently not, but I might have one for an LA100.
mike
I would like to get a Tek 4404 computer going but lack any service
manuals. The system turns on but has no curser on the screen. Has
good power from the Power supply and heater is on in the CRT.
Has a row of LEDs on the mother board. Does anyone know how
to read these.
- Thanks, Jerry
On 7 May 2010, at 08:25, cctalk-request at classiccmp.org wrote:
>
> Message: 2
> Date: Thu, 06 May 2010 16:06:37 -0700
> From: Al Kossow <aek at bitsavers.org>
> Subject: Re: Servant .953
> To: cctalk at classiccmp.org
> Message-ID: <4BE34B7D.6060902 at bitsavers.org>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> On 5/6/10 2:23 PM, Fred Cisin wrote:
>>> Al Kossow wrote:
>>>> I am interviewing Andy Hertzfeld tomorrow, and had hoped to talk about
>>>> Servant, but I can't find a copy of it around anywhere tonight.
>
> A huge thank you to Nigel Williams who forwarded a working copy of .951 five
> minutes before Bill and Andy arrived. We spent an hour talking about MacPaint
> and Quickdraw (Apple has finally given CHM approval to make the sources available)
> then another hour on Alice, Dali Clock, Servant, Hypercard, and Magic Cap.
Could you please clarify, the QuickDraw source is available for what purpose? Could developers modify it any include it in heir commercial 64 bit Intel applications for instance?
Is the source Pascal, Assembler, C or something else?
Roger Holmes,
Director of Microspot who has a Carbon application which compiles with over 10,000 warnings about deprecated QuickDraw calls.
When Multics was officially released as free software a couple of
years ago, there was a flurry of activity aimed at getting some sort
of emulator up and running to run it. Did anything ever come of that
or did folks just lose interest (or find out that the needed
GE/Honeywell hardware was too poorly-documented to write an emulator
of)
Mike
Hi,
Who can help me with a source (not IBM) for logic probe tips
used with IBM MST and SLT backplanes.
See: http://home.hccnet.nl/h.j.stegeman/IBM_logic_probes.jpg
Prefably the lower one (P/N 453826).
Thanks for your replies.
Regards Henk
I have a monitor for a Stardent workstation. It's a re-badge Sony, model
number 130-0001-01.
Free for pickup, or 1.2 * cost of shipping to recoup time and trouble if
you want it shipped.
Please respond soon if you are interested as it will be going off for
scrap in a week if there are no takers.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
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http://classiccmp.org/pipermail/cctalk/2010-January/282022.html
It always suprised me that hre BBC micro used the 6502 rather than the
6809. By the time the Beeb was designed, Acorn had made a 6809 processor
board for their System machines, so they must have had experience with
the chip. THe Beeb is nice, but a Beeb with a 6809 processor would have
been something else :-)
-tony
Hi! When I designed the N8VEM 6809 host processor it is loosely based on an
article I read for the BBC computer called "Dragon in the tube". I am not
very familiar with the UK microcomputers but apparently 6809 "coprocessors"
were fairly common peripherals on their Z80 and 6502 designs. I used a
similar concept for the N8VEM to allow its Z80 SBC to access the 6809 as a
"host processor" peripheral on the ECB.
One of the builders was able to get CUBIX running on the N8VEM 6809 host
processor using the Z80 as its "IO processor". However, I can see how the
implementation can get confusing because it is either a Z80 based system
with a 6809 coprocessor or a 6809 based system with a Z80 IO processor. In
reality it doesn't really matter but it's a matter of perspective.
The N8VEM 6809 CUBIX implementation allows the use of ECB peripherals like
IDE, video, floppy, serial, parallel, etc but it requires the Z80 to serve
all the IO based on 6809 commands. I added the 6809 IO mezzanine board
(power, ACIA, PTM, 2 VIAs, expansion bus) to give builders the option of
using the 6809 host processor as a stand alone computer or to add separate
IO to the N8VEM system when connected to the bus. The idea being to let the
6809 host processor interact with the outside world using its own IO and
only involve the Z80 when absolutely necessary.
The hardware seems to work OK but we'll see where the software goes. I
think with CUBIX the 6809 N8VEM system becomes a lot more practical. The IO
mezzanine fits on top of the 6809 host processor. You can see some photos
here. These are out of date but give a good idea. Recently I fitted an
improved serial cable and the nylon standoff hardware. Also the PTM seems
to be working and that's good.
http://n8vem-sbc.pbworks.com/browse/#view=ViewFolder¶m=m6809
I have many 6809 host processor and IO mezzanine PCBs so if anyone is
interested please let me know. This would be a great opportunity for anyone
who would like to do some 6809 hardware and software hacking.
I think the N8VEM 6809 host processor is the only system I am aware of other
than Dave's homebrew that is running CUBIX. There maybe some other homebrew
systems out there too I can't find them after some searching.
Thanks and have nice day!
Andrew Lynch
>
>Subject: VT-180 (Robin) EPROM images?
> From: "Robert Armstrong" <bob at jfcl.com>
> Date: Sat, 10 Mar 2007 20:23:04 -0800
> To: <cctech at classiccmp.org>
>
> Does anybody have images of the v2.1 Z-80 firmware for the VT-180 (aka
>Robin) ? At least, I think 2.1 was the last version ever released. They
>should be DEC part numbers 23-017E3-00 and 23-021E3-00.
>
>Thanks,
>Bob Armstrong
I have enough of them laying around I could supply the actual roms. I've
never imaged them as It's easier to replace the code outright.
Curious why are you looking for them?
Allison
Like the Sanyo just yesterday, I have a Compaq SLT/286 portable computer
taking up space. Very nice condition, with power unit, dock, and bag. Any
interest CHEAP? I am located in New York, zip 10512.
Unlike the Sanyo, if there is no interest, I suppose I will just chop this
up.
I am desperately trying to clear out a bedroom to work on it - the bedroom
that ends up being the junk overflow containment chamber. It would
actually be nice to sleep in it sometime.
William Donzelli
aw288 at osfn.org
