Hi all --
I just picked up an interesting device, it appears to be a drive
emulator that adapts DEC SDI to either ESDI or MFM drives (I would guess
ESDI, but no real way to be sure.) It's manufactured by "Micro
Technology" and is labeled as an "MDI 240" on the front. (On the rear
as "SPEC.MDI-240", P/N "970176-000".)
Mine has no drives in it, just a power supply and two logic boards
labeled "MSD13B" that connect to the drives. I can't find much
information about this unit at all, and just a bit about Micro
Technology (apparently they were sued by DEC for building this device :)).
I'd like to be able to use this thing (possibly with my VAX 11/750).
Anyone have any information hiding somewhere about it?
Thanks,
Josh
Agreed. The ? vintage camera shows do it the same way. ?Ed#
Sent from my Verizon Wireless 4G LTE smartphone
-------- Original message --------
From: Evan Koblentz <cctalk at snarc.net>
Date: 4/18/2016 11:52 AM (GMT-08:00)
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Subject: Re: Vintage Computer Festivals???
>Still, calling a hobbyist who
> sells some of his creations a vendor is a dubious distinction, in my
> opinion, since no one is making much money on these things, it's just a
> service for fellow enthusiasts. All of the other shows I attend (like
> the upcoming CocoFEST!) make no distinction.
We have a good reason for doing this.
Events that mix sales/exhibits together, without making distinctions
>from booth to booth, tend to become flea/swap-type events. That's fine
for those of us IN the hobby, but these events will only ever shrink,
not grow, as the audience/collectors get older.
Our goal at VCF is to produce awesome events that show vintage computing
to people * beyond * hobby insiders.
When people who have casual interest attend a VCF, they're not going to
come back if the room is a big confusing mix of exhibits and stuff for
sale. These people -- a massive audience vs. the few of us active
collectors -- aren't attending to find memory for their Banana 3000.
They're attending to be wowed.
> From: drlegendre
> Ok, so there's an annular groove cut mid-way along the length of the
> shaft. That might well be for retention of lubricant.
Yeah, that was my guess too.
> I took these to be the typical 'Muffin' type fans, that run about 600
> RPM.
For comparison, one of my desktops has a thing that reports the fan speeds in
that machine; it says the case fan there is doing 1.5K RPM, and the CPU fan
5K. Going by that, since these are going considerably faster than that case
fan, I'm going to say these are doing roughly 3K-4K or so.
Since they are 120VAC fans, i.e. 60Hz AC input, if I had remembered enough
EE, I should have been able to work out the speed from the number of poles on
the rotor, etc, but alas that's beyond me.
> This is a long-shot, but does the groove in the shaft communicate with
> a passage in the bearing
Nope, the cylindrical (outer part of the) bearing is a plain cylinder. But
looking at it closely, it's probably not copper, so it might be that Oilite
stuff.
> What's the diameter of the shaft, btw? 1/4" or less?
Pretty much about 1/4".
> I'd stick with the suggestion to use a light-bodied grease like Phil's
I'm just worried a bit about a grease, given the high speed.
For comparison, a car wheel is about 2' in diameter, or about 6' in
circumference, so at 60 MPH, which is 5280 FPM, it's going to be doing about
880 RPM, somewhat slower. Hence my thinking a fluid lubricant might be the
way to go, although of course fluids can migrate.
> But again, there's no harm in using a medium-body motor oil, like 30W
> or 10W-40. It's not as if it's going to be in 24/7/365 service, eh?
No, it's not, which is exactly the problem, though - I want something that
won't coagulate if left to sit for a long period.
Actually, now that I think of it, my son is a Mech E - I should ask
_him_! :-) They probably know about all this stuff!
Noel
On 14 April 2016 at 09:45, Rod Smallwood <rodsmallwood52 at btinternet.com> wrote:
> Whats the matter with Vintage Computer Forum ?
> Its got walls like Mordor
>
> I thought I might register. I filled out their form (tedious) and hit
> submit.
> It tells me my email address is already in use !
[..]
The forum was moved to http://www.vcfed.org/forum/ recently, with all
the original users and posts, and it looks like you registered April
29 last year. (search for yourself with site:www.vcfed.org/forum/ and
you'll find your user)
-Tor
Hi,
a recently acquired HP 9845B desktop computer came with a literally broken
power supply unit.
One of the ferrite core transformers has a broken core. The lower, U-shaped
core part is broken in the middle into two parts. Both parts are still
there, rattling around in the coil part / transformer fixture. I do not
think that I could find a new matching core.
I am not sure of the magneto-electrical requirements and would like to hear
about your experience or opinions:
- should I glue the broken ferrite core with e.g. super-glue or epoxy (of
course with ideally zero or minimum gap between the halves) ?
- would it work or are there better ways to fix broken ferrite cores (e.g.
adding a steel wire insert or something like that?)
Thanks,
Martin Hepperle
At 08:22 PM 4/17/2016, drlegendre wrote:
>... does it have the sintered look of oil-impregnated bronze (Oilite)?
If the bearing is bronze do not use ordinary motor oil, as its sulphur content may attack the bronze.
Dale H. Cook, Roanoke/Lynchburg, VA
Osborne 1 / Kaypro 4-84 / Kaypro 1 / Amstrad PPC-640
http://plymouthcolony.net/starcity/radios/index.html
Another weekend acquisition is a Fujitsu M2284 SMD drive (14" platters
under a transparent cover, what's not to love?). It's in good shape and
was properly locked down for shipping so there's a good chance it'll
still work with some coaxing. I'm missing the power supply, however. I
believe this is the Fujitsu Denso B14L-0300-0018A. Anyone have one
going spare, in any condition?
Thanks,
Josh
> From: drlegendre
> There are so many types, sources & grades of lubricating oil out there,
> it boggles the best of minds.
Speaking of lubricating oils... I've recently been cleaning/etc some of
the ~4" boxer fans that the earlier PDP-11's use in large quantities.
Some of the IMC fans (sleeve bearing) in the machine didn't really want to
turn; on taking them apart, they were absolutely full of dirt, and when
cleaned, spun up nicely.
However.. what lubricant should I use on them before putting them back
together for the long term? I assume I should use _something_? But the
machine's going to be sitting a fair amount, so I don't want something that
will dry out and/or gum up. What do people recommend? Would a 20SAE oil, as
used on small electric motors, be OK, or is that in danger of turning into
gummy stuff if left sitting for too long? Is there e.g. some silione-based
stuff which is long-term capable?
Thanks in advance for any/all advice!
Noel
Hello,
I got 2 x NCR PC4i computers. One is running fine at the moment but the
harddisk has some problems.
The 2nd one had a dead CPU and Bios rom. I replace both but got no beep
and nothing on the screen.
The PC4i has a 'rack case' for the motherboard. Changing the case shows
the same problem.
There maybe a problem with the power supply.
Does anyone have a service manual or other manuals for the NCR PC4i ?
Here is what I have:
http://oldcomputers.dyndns.org/public/pub/rechner/ncr/PC4i/index.html
--
Thanks - greetings
Mit freundlichen Gr??en
Fritz Chwolka
Hi,
After meeting up with Kyle Owen at VCF-East today, and booting OS8 via
OS/8 Disk Server on his system, I have renewed interest in getting my
pdp-8/e more functional.
Does anyone have an extra M8650 (KL8E) or M8655 (KL8JA) asynchronous
interface card they would be interested in selling or bartering?
Mark
--
Mark G. Thomas (Mark at Misty.com), KC3DRE
