<> ObCC: I just noticed /dev/drum on a Dec here. Now I *know* there
<> is not a drum on this thing, so this must be a holdover from some
<> earlier implementation of some Unix. True? Were filesystems on
<> drums managed the same as those on disks? I don't see any reason
Drum is serial storage just like disks. What distinguished some drom
is that ther stored words using multiple parallel heads making them very
fast. On PDP-10 I used in 70/71 had a 128kw swapping drum used to hold
the swap file. It's my understanding (and memory) it rotated at 1200 or
1800 rpm and stored 18 bit parallel words.
I've also used a PDP-8 that had RS/RF08 disk that was structured like a
drum with 12bit parallel access (32kw per platter). It was also quite
fast.
In all aspects durms and disks are the same thing.
<> why they wouldn't be, offhand. But I thought drums died out before
<> Unix appeared. Does anyone still have a functional magnetic drum
<> memory? That would be one _awesome_ peripheral. :-)
It didn't!
<No, no functional drum, but I own _parts_ of a drum from
<an SIEMENS 2002 - this wasn't a storage drum like later
<on, this computer stored the (working) REGISTERS on the
<drum (Background: the 2002 was the first fully transistorized
<computer). Thats prior to core memory tek.
Core predates transistors. The TX1 and TX2 were the mostly transistor
machines that also had core. They had some tubes(valves) as the high
current pulse drivers for the core drivers. I think Mark1 or Whirlwind
(all tube) had core.
Another use for drums was bit serial machines where register and main
memory were serial in nature and stored on multiple tracks of the drum
(or disk).
Allison
True? Were filesystems on drums managed the same as those on disks? I
don't see any reasonwhy they wouldn't be, offhand. But I thought drums
died out before Unix appeared.
I last used a drum on a Univac 1106 (FASTRAND II), the file system was
the same as a disk drive. A drum is just a 2 dimensional disk, track
and sector but no head select. Univac had fixed head drums and moving
head drums, don't recall the capacity (it wasn't all that big). The
drums on the 1106 were retired in 1971 when it was upgraded to a dual
processor 1108 with a room full of short stack disk drives (20MB packs).
Good thing too, the reliability on the drum wasn't so great, heads would
often get out of alignment, you would suddenly have half of your file
and half of someone else's.
BTW, as a bit of trivia, a friend of mine who worked for the CIA in
Vietnam had the job of actually grinding off all the oxide on retired
disks and drums, so there would be no possibility of recovering data
>from them. Might be one reason they are so scarce now.
Jack Peacock
Does anyone know of a *cheap* source of a VGA-compatible display? What I'm
looking for, especially, is low power usage, followed by compactness and
portability. Thanks!
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
Greets!
I was wondering if anyone might have any information on an old
machine produced by Tandy/Radio Shack. It came out _prior_ to the
Color Computer, but it looked like a CoCo. However, it was a
modified with a phone jack in the back for a TV/monitor and ran off
of a 6809E (???). It basically was a videotext terminal of some
sort.
If anyone might have some information on this little unit, your help
in learning more about it, and it's purposes, and maybe some history
on it, would be much appreciated.
Oh, yeh... an off-topic question? Is this text formatted correctly.
I had some problems with my mail software and had it completely
messed up trying to fix the original problem. Anyway, let me know if
the text is going off the right of your screen or whatever, and if
my signature box at the bottom of the page is formatted ok, ok? If
it is, great! If something's wrong, feel free to send a private
e-mail back to me to let me know ok?
Thanks,
CORD COSLOR
--
____________________________________________________________
| Cord G. Coslor : archive(a)navix.net |\
| Deanna S. Wynn : deannasue(a)navix.net | |
| on AOL Instant Messenger: DeannaCord | |
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\_____________________________________________________________\|
At 08:27 AM 6/10/98 +0000, you wrote:
>> I've found Toshiba's on-line support for their older machines to be
>> excellent; I wouldn't be surprised at all to find that the setup pgm was
>> available on their web site. Definitely worth checking out.
>
>True, I know but that is very flimsy. Toshiba can decide to pull
>those files off, never know.
Yes, Toshiba could yank the files from their site, but unless they went out
of business (not likely) why would they? Doesn't cost them anything
(coupla meg of hd space) to keep them there. Probably more expensive
(people time) to get rid of them. An incredibly valuable marketing tool
for very little (or no) cost. Because of what I found there, I would
definitely consider a Toshiba laptop.
>else. IBM, Gateway what you have that have long term service
I wouldn't touch a Gateway computer to save my life. I've got a Gateway
2000 Colorbook that my sister uses. I sent them an e-mail to simply ask
what models hard drive they used (I got some empty sleds, and my hard
drives didn't fit) and if they still sell sleds/hard drives for it. Was
told they didn't know, didn't care, not interested. Suggested a couple of
places that sell used GW2K stuff.
I have a long-standing loathing of IBM, though I must admit some of their
more recent laptops look pretty nice. (Can't stand the damn erasers,
though.) They do seem to be pretty good about offering support and info on
older machines.
Basically, if a company isn't interested in helping out with their older
(sometimes much older) machines, I'm not interested in their new machines,
simply because whatever I buy today I'll still be using when it qualifies
for this list.
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
> But the VAX-philopsophy was extreme CISC, and that extended to the
VAX/VMS filesystem as well: record-based, with a zillion different file
attributes, built-in file versioning, etc. It was hierarchial, but
mixed with a clunky "volume" concept (something like DOS "C:", but with
longer names).
I wouldn't call it "clunky". In fact with VMS you can combine drives
into a volume set if you want the filesystem spread across multiple
drives, or you can treat each drive as an isolated filesystem. As a
system admin, I prefer the separate volumes, makes it easier to manage
overnight backups. In our VMScluster individual disks are backed up in
parallel across several tape drives (as many as four tapes in operation
at the same time, depending on day of week), a trivial task in VMS but a
bit more elaborate on a Unix system.
As for the RMS file attributes and versioning, they are a dream for
programmers, compared to PC or Unix systems. We have NT or W95
workstations at every desk, but we still keep a VMScluster running,
partly for financial apps, and partly for coding. When you start
dealing with larger apps (i.e 3K-5K users per week, 300-500 at any one
time in a 24 hour day, all accessing the same files) you start to
appreciate what VMS can do.
BTW, one nice advantage of filesystem per disk is drive shadowing in
VMS. You can mirror two drives during the day, then break the set,
remount the mirrored drive as a separate disk, back it up, then
reconnect it back to the shadow set. Instant snapshot backup without
shutting down applications, all the database files are intact as of the
moment you broke the shadow set, no updates during the backup.
Jack Peacock
I've seen him/her/them/it post on alt.folklore.computers about several topics
recently, IIRC.
david
In a message dated 98-06-12 00:56:28 EDT, you write:
<< BTW, whatever happened to lisard/communa? The consistency with which
"they" used pronouns was impressive: IIRC -> iwrc.
-- Doug >>
<On Thu, 11 Jun 1998, R. Stricklin (kjaeros) wrote:
<
<> I suppose a better way of asking that is how is a 'bit sliced' processo
<> or ALU differentiated from a 'normal' one?
The concept was to take a vertical slice of the core of most cpus and make
it so they can be cascaded to the needed width. Some of the common parts
were the 3101 (intel 2 bit slice) and the 6701/2901 4 bit slices.
Their advantages were speed, they were bipolar and in the 70 to early
80s you could make a z80 equivelent using them that was 10mhz and
piplined. Or a custom 20 bit machine.
<BTW, I mentioned a while back that I wrote a simulation of a PDP-8 built
<from 2901's. I finally found the source code for everything but the
<assembler (but I did find a grammar spec). It's not in good enough shap
<to "publish", and I don't plan to spend the time to get it there, but if
<anybody wants a copy, let me know and I'll send you source. (It's
<curses-based, and should run fine on any Unix or DOS box).
I'd love to see that... I have a big bunch of 2901s doing nothing.
Allison
Found the following on Usenet. Please contact this guy directly if
interested.
-=-=- <snip> -=-=-
From: "Joe Huber" <jhuber(a)anet-dfw.com>
Newsgroups: comp.sys.dec
Subject: need to get rid of Vax manuals
Date: Wed, 10 Jun 1998 17:07:50 -0500
Organization: ANET Internet Services
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X-Newsreader: Microsoft Outlook Express 4.72.2106.4
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I have a nearly complete set of VAX/VMS 5.5-2 manuals in 3-ring binder
format. There are also bound manuals for DecForms (still in the plastic
wrapper), DecPrinting services, several other things.
I sold my VAX but the buyer did not want the manuals. I hate to throw them
out.
I'll "sell" them for the cost of shipping. Please respond via email if
interested.
Thanks!
--
Joe Huber
jhuber(a)anet-dfw.com
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