From: Michael Kerpan<madcrow.maxwell at gmail.com>
"...I also have the operator's console from a B2700 but it's promised to a
fellow list member."
Mike - you gotta get it right. You have a "SPO" from a B2700 ;-)
Steve (Small Systems & Medium Systems enthusiast ;-)
Hi Folks,
I'm restoring a DEC PDP/8m, which is missing a serial (asynchronous) I/O board. Doe anyone have one that they would be willing to sell?
Thanks,
Steve
http://www.tronola.com
I have a problem that cropped up that spans both old systems and flaw
maps / disks that have flaws to skip over and current technology.
In the old days with my experience on a lot of cdc winchesters and
removable pack smd drives (and trident) there were flaw maps you could
use in a controller to figure out where the bad spots were.
When shipped from the factory the mmd / cmd / emd / fsd drives (at least
the first two) were not allowed to have more than a false address mark
on a track, and a limit of maybe 5 for the entire stack. Later at least
on the mmd's they had run of marginal media and upped the FAM errors
considerably. (10? 15? don't recall). I later found some drives
delivered to such as Datapoint for large systems delivered when we got
the story about the FAM problem (needing to up the count) that had zero
flaws, but that was 10 years later buying some scrap drives (better than
the ones I had purchased 10 years before, still working).
Anyway, recently I had a system with a 1.5tb seagate grow a count of
"uncorrectable offline sector count" errors. I'm telling this up front
since these are effectively the same as the above errors, sectors that
are not recoverable by the drive and presented as bad or timeout spots
when you seek to the sectors.
The errors were not there when I initialized the linux system on the
drive, and grew later. To complicate things a bit this was part of a
LVM raid ext3 raid 5 set, so there are other complications here, but the
initial build was flawless, ran about a 6 months then this drive grew 16
bad errors visible to linux.
So, I have now got the situation where there is a bad spot in a file
(more complicated because this is part of a raid set, but bear with
me). If you power cycle the drive set they do a scan of the media with
the raid system I'm using (linux based) and hang before releasing it for
server operations.
That is the only flaw that there was, and I had a brick. Thank heaven I
could put it in a desktop system and recover the data (7tb of it).
Anyway, have we lost the capability with such as Linux to run with flaws
growing on media at the level where transfers from media come from the
drive target to the host, or did this vendor of raid equipment
(appliance was readynas nv2+) have a flaw in their bringup procedure.
I am glad I shopped and got a system with raid 5 support like this with
a linux system that I could take out and troubleshoot with any linux
tools, rather than hardware raid. Dodged that bullet.
but I am disappointed even so with the behavior of the raid set when I
put it on my recovery system. I think there is a basic loss of what one
would have been accustomed to in earlier times with media, throwing
their hands up with defective media.
I was only able to narrow down the error with manual applications of
careful dd commands and shell scripting (lacking a better tool) to see
the errors. There is a nice timesaving web page if you hunt around the
pages found by searching for smart errors.
At least that is a nice tool, telling a lot about the drive.
I am not going into why a 1.5tb drive with huge amounts of extra space
(as I understand it probably > 500gb) can't reassign media 16
consecutive sectors, as that is a totally different discussion.
Jim
----- Original Message -----
> Date: Sat, 06 Oct 2012 10:53:15 -0500
> From: Jim Brain <brain at jbrain.com>
>
> Here is what I use to send products to people:
>
> http://www.correctproducts.com/ESD-Packaging/High-Density-Black-Conductive-…
>
> It's a bit cheaper per sq inch than mouser, and they offer different
> thicknesses (I use 1/4")
>
> Jim
-----Reply:
Recycled styrofoam wrapped in aluminum foil works for me and is practically
free...
mike
David wrote:
>If a second disk dies in *my* RAID, it's annoying, but I don't lose
>data. Well, I lose anything since the last backup, but given that those
>happen every 24 hours, it's not *that* much data and I can reconstruct
>it pretty easily.
Guess it depends on (a) whether it's personal or business and (b) (if (a) is business), how good your
secretary is. I'd rather replace the disks than spend hours dealing with people who come in grumbling
about their work for today disappearing. Also, for most non-miniscule businesses it's cheaper to replace the
drives preemptively than it is to pay for people to recreate the work done since the last backup if more drives
fail.
Can anyone help my friend Kyle out? Please email him directly - kylevowen at gmail.com
> I'm trying to revive a N* Horizon, and as I've found out, you have to have a booting machine to make boot disks. In order to have a booting machine, you either need a boot disk or a ROM board. My processor board doesn't have a ROM option, so I'm out of luck. I have supposedly 4 boot disks, but none of these seem to get the computer booting, though I hear the drive head move back and forth as it seems to read the disk. I still don't get any output into the right serial port.
>
> Does anyone have access to a bootable Horizon? I have a few hard sector floppies, so if I could get a boot disk copied, that'd be great. Optimally, I'd like to try to read these disks on a known working machine before having to overwrite any. Two aren't labeled, so they may very well be blank. All of the others have labels indicating some possibly neat programs, like Microstat, WordStar, and Mailing List Utility. About half of the disks are labeled Care. Care System, Care Data, Care Source Code, and so on. Any idea what the Care System could be? Another one is from Validata Computer and Research Corporation, which apparently is still alive an well in Montgomery, AL. It's entitled "5 Meg Hard Disk Start Up Diskette for Worcs, PM, Care Systems". No telling, eh?
>
> My system has a CompuPro 24k SRAM card (with only 20k populated), a N* RAM16-A3 16k RAM card (fully populated), a N* ZPB-A2 processor card (no ROM option) and a N* MDS-AD3 double density floppy controller, all on a N* HRZ-MB-3 motherboard. From the double density FC, I would indeed need a DD boot disk. Judging from the date codes, I would date this particular machine to 1979.
>
> Thanks,
>
> Kyle
Best,
David Greelish
- Computer Historian, Author, Speaker, Blogger & Podcaster
- Founder of the Atlanta Historical Computing Society
Producer of the Vintage Computer Festival Southeast 1.0 - 2/9/13
http://about.me/davidgreelish
Resend. My messages haven't been making it to the list.
From: "Chuck Guzis" <cclist at sydex.com> wrote:
> On a related note, a friend of mine found in his collection a full
> sealed can of whale oil, from ADM, no less. We are not sure what to do
> with it.
If it's really old, then it might be for illumination (burned). But
ISTR that whale oil was also used for lubricating instruments, such
as clocks and watches. So it might be worth quite a bit, assuming
the stuff doesn't go rancid with age.
--Chuck
Whale oil was used in a lot of precise mechanical devices that required a fine stable oil that didn't gum up. Clocks and watches were one application, as were some early mechanical calculators and toys.
I used to carry it with me for working on Selectrics and teletype paper tape gear. Would love to find some more - have been looking for 20+ years for it. If your friend wants to sell it, I would be interested.
Billy Pettit
