Hi
I am designing an ECB bus backplane for my N8VEM SBC project and am looking
for some peer review prior to going to manufacturing of these PCBs. The
N8VEM SBC seems to be working out alright. About a half dozen people have
successfully built the SBC so now it is time to start thinking about
peripheral expansion.
Although the N8VEM SBC uses the ECB bus for expansion, I have not ever used
ECB bus machines as they are common in Europe but extremely rare in the US.
I have made an ECB bus backplane prototype using prototype boards and it
works well enough so I think the basic concept is sound.
However, I would like to make this ECB backplane as common and general as
possible so other hobbyists can use it not just N8VEM SBC builders. I would
really like to avoid any inadvertent N8VEM unique extensions.
If you have experience with ECB bus based machines, I would like to hear
your comments and suggestions.
So far, the ECB bus backplane has six DIN 41612 connectors. All 96 pins are
routed. Pins for IEI/IEO have jumper pads per connector to allow usage of
Zilog peripheral interrupt priority scheme. The backplane has its own Vcc
and Gnd, including a power switch and LED power indicator.
The PCB is 2 layer to keep costs low. Each side has a ground fill zone for
a low impedance ground. I will be using the double thick PCB material (3.2
mm) for rigidity and the double weight copper trace for low impedance.
Vcc and ground traces are triple wide (51 mils) minimum and also routed on
both the component and copper sides of the board. The rest of the traces
are the usual 17 mils wide.
After I order some of these backplanes, I will make them available in a
similar fashion as the N8VEM SBC. The PCBs will be available for $20 each
plus shipping. The builder will have to source the rest of the parts.
If you are interested in helping or have questions, please review the PCB
backplane design at:
http://groups.google.com/group/n8vem/files?&sort=rdate
There are two recently uploaded PDF files containing the schematic and the
PCB layout.
Thanks in advance for any *constructive* feedback. Have a nice day!
Andrew Lynch
>
> My word! I'm astonished at the levels of interest in this box. I'm
> still trying to contact the donor to arrange collection at the moment.
>
> In addition to this thread, I've also had multiple emails from
> would-be claimants; between multiple time zones and transmission lag,
> I have no idea who was first.
>
> My current thought is this: I could put it on eBay, and whatever the
> selling price it goes for, I will donate that to Bletchley Park or
> some other suitable charity relating to preserving classic computers.
>
> How does that sound to everyone?
Sounds very fair to me, though I was not one of the claimants as I
have had one of these from new.
On a related subject, the mains cable of my UK101 has become sticky
where it has been in contact with expanded polystyrene for many
years. Has this happened to anyone else and does anyone know if this
is a chemical reaction? It might just be coincidence and maybe I
spilt something on it and have forgotten about it. I used a large
ceiling tile to stand the machine on when I first got it so it would
not scratch the table and its been there ever since. Yes I know NOW
about static and expanded polystyrene (I think its called styrofoam
in the states), but back then all the 74 series chips I bought, came
by post pressed into bits of normal white (non antistatic) expanded
polystyrene so I presumed it was safe, apart from the fire risk of
course.
I bought my UK101 ready assembled though I had to insert the second
4k of chips about 6 months later because every time I rang to
complain they said they went out yesterday and were in the post. By
the time I got them the chips had fallen in price considerably. I
built an expansion board with a 6522 on it though I cannot remember
why, nor what a 6522 can do. About then I was offered a moonlighting
job programming the Apple ][+ with the offer of a machine (with two
disk drives) as payment so I lost interest in the UK101.
----------Original Message:
Date: Sun, 20 Jul 2008 11:31:31 -0400
From: Dan Gahlinger <dgahling at hotmail.com>
Subject: the "history" of the Internet/Web
<snippage>
>So continue with your stupid jokes, and ancient references that mean nothing to the public at large.
>I thought this list was a bit more mature than this
>So fine, into the garbage a piece of history goes. congratulations! I hope you're happy
>Dan.
----------Reply:
You're absolutely right; we all need to feel guilty and assume responsibility for
your decision to throw this (so-called) piece of history into the garbage.
You have so much to teach us about maturity; thank you!
m
> Chuck Guzis wrote:
> But that little monitor!
It is small, isn't it? But it's very sharp, even on 80x24 text, so it's
easy to read if you sit about 6" away from the screen. Makes me want to get
a Fresnel lens on a swing arm, a la Brazil :-)
Bob
All
I have 6 SGI Octane computers available for free to anyone who can
come by to pick them up. They have various sets of memory and
graphics cards, and if you're interested and can pick up in Tucson,
I can do a better inventory for you ahead of time. All were
working as of last usage, but will be delivered without a hard drive
( but with the hard drive sled !! )
I also have three VS160 Quantum scsi DLT tape drives and two Quantum
scsi autochangers that hold 8 VS160 tapes.
Again, the machines and the tape drives are free, but I'am not able
to ship ( but I could drop them off someplace locally, if you made
arrangements for someone else to ship them... )
Mike Ingram
I have three PCjr units. One has four sidecars. One has one. The third
has none. There are also four chiclet keyboards, four "regular" keyboards
(one sealed new-in-box), a technical manual, and lots of keyboard
overlays.
Make me an offer.
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
>Date: Tue, 15 Jul 2008 12:45:43 -0700
>From: "Dennis R. Cohen" <drcohen at mac.com>
>Subject: USUS Software Library
>
>
>Hi,
>
>A long time ago, I was pretty active in USUS and have a pretty complete
>copy of the USUS Library. Your article implied interest. The bulk of the
>set is on 8", but there is some on the 5.25" that I used with the Sage
>II.
>
>I'm getting ready to move from the Silicon Valley to Spokane, WA, so if
>you are interested, please contact me while I can still find them. I
>also have an old Sage II with Televideo 925 terminal and an Apple /// if
>your USUS Museum would be interested. I would be willing to donate them
>if you have someone to come and get them.
>
>Dennis R. Cohen
>Sunnyvale, CA
I'd pile on here but the point has been well made by far. Sheesh.
--
Sellam Ismail Vintage Computer Festival
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Brian L. Stuart said:
> The "first" of one of these warrants very little historical interest.
I disagree with just this part. It is of interest, but your point is
taken.
--
Sellam Ismail Vintage Computer Festival
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>-----Original Message-----
>From: Evan Koblentz evan at snarc.net
>Sent 7/17/2008 11:45:18 PM
>To: 'General Discussion: On-Topic and Off-Topic Posts' cctalk at classiccmp.org
>Subject: RE: "first" computer on the internet
>
>Also ... Who is this man? Here's a bio:
>http://en.wikipedia.org/wiki/Einar_Stefferud
>
>
That Wikipedia page is like a year old, and I can't really find much info on that person.
Besides the fact the Wikipedia is about as trustable as a lion in a butcher shop, where everything you type becomes "fact."
I worked at Citrix Systems back in 1994 until 1995, and we ALREADY had system on the Internet, or internet, when I started there early 1994, and already had CITRIX.COM, and used it for email back then. We used the Microsoft Gateway for MS Mail.
I also remember registering ASPID.COM with Ann Westine @ ISI back in about 1991 or so, and there were ISP's cropping up already, with UUNet being the leader (at the time) - I happened to be going through the University of Miami (FL) using mthvax.cs.miami.edu, first using UUCP, and later SLIP/PPP.
I mean - wasn't AOL and CompuServe accessing the internet by then?
I think the email address had to have :INTERNET> prefixing it, or something similar?
A Sun SLC? in 1994?
Don't think so - way too late to the party - we were already drunk!
T
No, no ... email is pipes. Didn't the Romans invent that?
-----Original Message-----
From: Fred Cisin <cisin at xenosoft.com>
Subj: Re: "first" computer on the internet
Date: Fri Jul 18, 2008 4:34 pm
Size: 34 bytes
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
When did Al Gore invent it?
I've seen worse, as recently as a few days ago. A beige/brown
color-schemed ADM 3a came in for recycling and it looked like the CRT face
was ready to just fall apart. It was literally almost ten times worse
than that in the subject eBay auction.
> I'm unsure if we've ever come to the conclusion if this is just an
> adhesion separation issue resulting in blotches resembling mold, or
> actual mold causing the separation. (Have we had some sort of cause
> for this problem?)
We came to the conclusion that it was a delamination issue. If you can
find it in the list archives, one of our intrepid list members did some
experiment that pretty much conclusively proved it was delamination.
These are now starting to be worth real bucks. I say they are worth
getting in any condition at this point, especially if they can be
rehabilitated. I think if someone can find an equivalent CRT in a common
piece of gear, like maybe an Apple monochrome monitor, then that would be
useful. I guess I could do that, if I make the time.
$250 is way too high for this one. Drop the zero. But add $25-$50 for
the original manual.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
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> Date: Thu, 17 Jul 2008 12:34:54 -0500
> From: "joe lobocki" <jlobocki at gmail.com>
> On 7/17/08, Jeff Walther <trag at io.com> wrote:
>> My bad. I was thinking of "autoinject" and not 800K vs. 1.44MB.
>> However, unless you're a purist for collector's reasons, I think the
>> 1.44
>> MB drive will work fine in the SE. It will read and write 800K and 400K
>> disks just as well as an 800K disk drive.
> jeff, you may be right, but my understanding was that a 1.44 drive
> wont function in a system with an 800k set of chips, and that it needs
> to be chipped or the logic board swapped. yes, I am a purist, but i
> think i might be able to slide on this one if it works.
First, please do not top post, and please do edit away irrelevant quoted
text.
Second, the 1.44 MB drive will not function as a 1.44 MB drive in a system
with 800K chips. However, it will function just fine as an 800K drive.
There is no chipping or logic board swapping needed to use the 1.44 MB
floppy drive as an 800K drive. The only possible issue is the floppy
drive cable, as I wrote earlier, but the difference (IIRC) was only one
line which would be easy enough to change.
Still, I'm pretty certain that the floppy cable issue was one of
auto-inject vs. manual-inject drives, not 800K vs. 1.44MB drives, because
I remember installing an auto-inject drive in a machine normally equipped
with manual-inject drives, once, and the drive began continuously
ejecting. That's caused by a difference in the cable, but is completely
irrelevant (IIRC) to your situation.
Jeff Walther
Jules sayeth:
> I believe Sellam still has an offer open to analyse the decay if someone
> can send him a sample - I'd already ditched the pile of rot from the
> HP-250 by that point.
Yes, I believe that opportunity is still available. But I don't think
that's necessary. I think one could be analyzed adequately if it was
removed, de-vaccumed, and a hole of 1cm is drilled through the face where
the affliction is at its worst. Then blow the dust away and see what you
got.
If there's something biological there, isn't there a simple test you can
apply (say "hello" to it and see if it responds)? If it's delamination, I
think it will be apparent at the cross-section.
The drilling would not be that trivial, but doable.
If I get time I'll try this, just to put this to rest once and for all.
--
Sellam Ismail Vintage Computer Festival
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International Man of Intrigue and Danger http://www.vintage.org
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Terminal Buffs and others interested:
I've seen screen rot before -- even owning one with perimeter
symptoms, but this is an example of _extreme_ "screen rot" (separation
of the protective plate from the CRT) on an ADM-3a.
See picture(s) --
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=360070017833
I realize this issue has been brought up and discussed numerous times
in the past -- but I thought I'd give ClassicCMP'ers a peek.
I'm unsure if we've ever come to the conclusion if this is just an
adhesion separation issue resulting in blotches resembling mold, or
actual mold causing the separation. (Have we had some sort of cause
for this problem?)
Anyway, FYI for those interested. May be good for parts, although the
initial bid price is a quite high side given the condition.
-eric
P.S. I have no connection to the seller, am not pushing a purchase in any way.
Donzo quoth:
> WHACK!
>
> You should know better - put quotes around *your* first, mister.
Silly, of course you know I meant on The Internet :)
--
Sellam Ismail Vintage Computer Festival
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International Man of Intrigue and Danger http://www.vintage.org
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[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
Unless "First" (in quotes) signifies its node name was "First", I don't
know how it could be the first on the internet.
Year of first internet node connectivity: 1969
Year Sun SLC Workstation was brought to market: 1990
There's a 21 year gap there.
The first e-mail communications occured sometime in the 1970s.
What are we missing here?
--
Sellam Ismail Vintage Computer Festival
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International Man of Intrigue and Danger http://www.vintage.org
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http://www.vintage.org/2008/east/exhibit.php
A few details (exact show schedule, lodging, etc.) are still being worked
out. But exhibit registration is now open. Please start using it and let
me know ASAP if you encounter any problems.
Hi there,
I am sorry I do not know your name and I came across your message while
browsing and I am hoping you can help. I have dusted down my old programmer
a Bytek 135H as I have a project I where I need to program an eprom. Have
not used it for some time now and have lost the manual and application used
to drive it. There was a floppy I used to insert into my PC, however it was
so long ago all is lost or misplaced it.
I am trying to find out some details on the unit. Did you ever locate a
copy of the application floppy and manual for the unit you acquired?
Regards,
Peter
Fingers crossed. Mylor Australia.
I'm working on a consulting project that is ballooning in terms of
equipment needed.
I am seeking the following computers:
Toshiba T1600/40
Macintosh IIx
IBM PS/2 Model 90
Any AST laptop that was brought to market prior to Fall of 1989 (must
include original power brick)
Atari STacy
Cosmetic condition is not a concern, but functionality is: they must work.
Please contact me at your earliest convenience if you have any of these
computers you'd like to sell. Time is of the essence, so please contact
me soon.
Thanks!
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
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[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
I've more of these than anyone will need and they're all brand new.
3 packs of Bernoulli 5.25 44meg disks
KAO 5.25 88meg syquest disks. The label inside says they are formatted for
Macs but includes software for wintel machines also.
$1 each plus whatever for shipping and they're yours. Just say how many you
want.
--
I am not willing to give up my privacy for the false promise of 'security'
Well, nice work on his part, but all he had to do was e-mail me and I
could've sent him a perfect copy, which I've had for years, and which I've
given out to several people.
Also, I simply read the program from a copy I have on tape into an Apple
][+. Once you get the volume levels correct on the cassette tape (not
trivial, but do-able after enough tries) then it's a no-brainer. No fancy
waveform graphs or C code required.
Finally, Apple-1 BASIC is simply "Integer BASIC", which came with the
Apple ][ and is pretty readily available itself.
Anyway, it was a nice intellectual exercise.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
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[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]