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Date: Sun, 22 Jul 2007 17:23:01 -0500
Groups: alt.sys.pdp8
From: "Gordon S. Hlavenka" <nospam at crashelex.com>
Reply: nospam at crashelex.com
Org: Crash Electronics
Subject: Re: Spare cards for 8/L
Re: <caSdndv8Zf4_zT7bnZ2dnUVZ_hisnZ2d at rcn.net>
Id: <aNQoi.3559$Dx2.1358 at newssvr17.news.prodigy.net>
========
Chuck Harris wrote:
> Try and order up a 74181 of any flavor, or a 74182. Or a 7438.
I used to own an electronics store, and most of the inventory is still
stacked around the garage, crawlspace, attic, etc...
Anyway, I have about 90 of the 74182, and a dozen 7438. (I don't have
any 6100s, sorry :-) I also have a lot of other older ICs; 74xx, 74F,
74S, and so on. Even a few 5400 family.
The store is gone; I just couldn't bear to dump all the STUFF, ya know?
But if anybody's looking for ICs or discretes to resurrect an old
machine, let me know and I might be able to help out for the cost of a
SASE and some change.
--
Gordon S. Hlavenka http://www.crashelectronics.com
It's bad luck to be superstitious
I have the Seagate version of the CDC Wren-4 (ST4376N) and I was
wondering if anyone knew of an easy fix for the following fault:
Disk spins up (jumpered to spin up automatically) head lock clicks up,
two "burbles" that I think mean head seeks and then the drive shuts off
and the heads lock again. I don't see any lights flash on the front,
but I'm not sure if it has an activity LED.
Can Someone repost the link to the scans?
it sounds like an interesting project.
1966 Mag: Build NE-2 Neon Bulb Computer
> - scan available
Bill
____________________________________________________________________________________
Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games.
http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow
I have two 7" reel mag tapes upon which I recorded the Fortran
sources to VMS Empire.
I would like to pass them on to someone that can read and play it.
Both are dated 3-Oct-80 version V3.B7
One says "DOS Format" on it. I'm not sure if the other is DOS or
something else.
Each tapes is in a plastic two piece container, and the write rings
have been removed.
These would have likely been code that I submitted to one of the
DECUS releases.
Yes, I had something to do with the VMS Empire, but it was mostly
debugging and getting it to run on VMS.
It was also probably one of the first cases of code pilfering over
the DEC network, as my eventual partner in VMS made a copy the code
out of my development directory in the Mill.
The original code was written by Walter Bright on a DECsystem 10.
Depending on the responses, I'll figure out whom to send this to.
Given that it was released to DECUS, are the DECUS distributions
accessible somewhere?
Dave.
Well our IBM RT / 5085 / CATIA setup all checks out and the hard disks seem
good - it'll boot to a login prompt on the MDA console (and issue a message
about the 5085 interconnect being happy)
Unfortunately we have no idea what the root password is :-( Tried the obvious
guesses.
Are there any kind of tricks in order to reset / break the root password under
AIX 2.1? We seem to have a reasonable complement of AIX floppies - perhaps
there's a way in there? Or maybe an insecure account which can be used to
snarf the passwd file (did AIX use shadow passwords)? Or maybe a way of
dropping to single user on the console without a login password? etc. etc.
Sadly the hard disks are ESDI - if they were SCSI it'd be trivial to stick
them in a different machine and start hacking at the disk block level.
Last resort I suppose is to install a copy of the OS on another drive, then
attach the current OS drive as a secondary, mount the relevant partition, and
edit the 'current' password file. That's a lot of effort though, and I'm not
sure what we have in the way of spare ESDI drives anyway. (I don't think we
have full install media for additional things like CATIA, so reinstalling the
OS over the top of the current data is something we'd like to avoid)
cheers
Jules
> > William Blair wrote:
> >
> > Just as an off-topic diversion from a subject that I don't think is actually off-topic, here
> > are a number of die photos including some from the AMD 29xx and 29xxx series and others:
> >
> > http://diephotos.blogspot.com/
>
> Brent Hilpert wrote:
>
> ..no need to consider it off-topic, a lot of the photos in there are of old
> chips, including an 8080 and 1802.
>
> One of the links on that page,
> http://www.cacs.louisiana.edu/~mgr/404/burks/pcinfo/hardware/cpu.htm, presents
> an interesting overview of microprocs from 70/80/90's, both well-known and
> lesser-known ones, far more than just a timeline.
Thanks. I guess I should have mentioned that it's my web page. ;-)
Best regards,
Bill
____________________________________________________________________________________
Yahoo! oneSearch: Finally, mobile search
that gives answers, not web links.
http://mobile.yahoo.com/mobileweb/onesearch?refer=1ONXIC
> He mentioned that they were having problems with a particular Memorex
> tape.
My sympathies. I have hundreds of reels of the crap I have to deal with.
> Apparently they've tried
> heating it, but this hasn't improved things
You have to supply a LOT of air for it to have any effect. The humidity
needs to be low, though that is generally a side-effect of getting a
chamber up to 55deg C.
> can anyone
> suggest companies or organisations in Britain which could deal with
> this?
Not that I have any personal experience with.
The brands pointed to by the spectrumdata page are the WORST of the worst
(ie. silver label memorex circa. mid-80's)
The only person I know who claims to have 'solved' the recovery problem
uses custom transports and industrial-sized tape ovens. He is completely
unreliable, though, and has personally ripped me off for several thousand
dollars worth of tape transports and heads.
The two failure modes I've seen on binder is layer-layer adhesion, which can
be reduced through baking, and binder deposit if the tape EVER stops moving
during reads.
The tape should be baked, cooled, then retensioned on a transport with no read-write
head, then read using the best transducer you can find WITHOUT STOPPING. There is a
high probablity with Memorex tape that even after all that the head will still drop
out from binder clog.
Analog data recovery and DSP techniques have been used successfully to recover 7 track
tapes that were unreadable using the data separators on the drive. Magnetorestrictive
transducers like the IBM 3480/3490 heads are more sensitive than conventional inductive
heads, but don't map exactly to the track layout of 7 and 9 track drives.
At the recent BCS at 50 event, I spoke to Dr Jeremy John from the British
Library. He is their "Curator of Digital Manuscripts" and as everyone
here will know he has his work cut out trying to preserve and access the
documents they have.
He mentioned that they were having problems with a particular Memorex
tape. I think this is 9-track tape. It sounds like the binder has
failed, and the oxide is lifting off the tape. Apparently they've tried
heating it, but this hasn't improved things (I'm not sure how many tapes
they're dealing with).
I think the following is what they are dealing with:
http://www.spectrumdata.com.au/content.aspx?cid=155
Rather than ask for specific remedial suggestions here, can anyone
suggest companies or organisations in Britain which could deal with
this? I'll pass suggestions on, or if you think you can help directly
then I will put you in touch.
Thanks,
--
Lawrence Wilkinson lawrence at ljw.me.uk
The IBM 360/30 page http://www.ljw.me.uk/ibm360
On 7/20/07, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
> The OSC signal was the 14.3xxx MHz master clcok signal in the PC and XT...
>
> It was used, of course, by the CGA card as the master clock for the video
> and colour cubcarrier timing. Some other cards used it, often divided
> down, as a master clock.
Is there a list anywhere of what cards tended to use that signal? I
ask because I manufacture the GG2 Bus+ bus adapter for the Amiga, and,
because that signal is on the ISA bus, the designer of the card
slapped a $3 oscillator on it to provide it. I have a number of
unassembled cards and, honestly, would like to leave that signal off
if there's no expectation of folks needing it.
These days, the most common use for an ISA bus on an Amiga are either
for Ethernet (NE2000 or SMC 80x3) or serial (8250/16550). There are
other drivers, but nobody really cares about those anymore.
Certainly, nobody I am aware of is hanging a CGA card off of an Amiga,
but there's no reason why it wouldn't work from a technical standpoint
(and the holes are on the board for the oscillator anyway).
So... after the AT faded away and folks were running EGA and VGA on
386s and up, was the 14.3xxx MHz signal still relevant, or just an
artifact?
-ethan
Hi,
>> Brings back memories....the 2B was my first modem back
>>in '85.
>
> Did you get it from 'Display Electronics'? They were advertising
>them at the time....
As a matter of fact I did, though indirectly.
One of my friends drove to their shop in London to buy one of those SMD(?)
hard drives they were selling at the time and picked up the modem while he
was there.
I got it about a month later when he got bored of it.... :-)
>> I may still have some documentation somewhere if it's any use to you?
>
> I'd be interested in knowing what you've got, certainly...
I do recall getting hold of a technical manual for the unit from a vendor at
a rally, since the documentation supplied by Display Electronics was little
more than a double sided sheet of A4.
I've had a quick look around for it, but it hasn't turned up yet. If I can
find it you're more than welcome to have it, but in those days I had a habit
of not holding onto documentation when I disposed of stuff.... :-(
I'll keep you posted.
TTFN - Pete.