At 04:07 AM 10/7/98 EDT, you wrote:
>Chameleon, I may have a manual or two.
If you do, would you be interested in getting rid of them?
--------------------------------------------------------------------- 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/
Oh yeah, these things are like, mondo-cool. Generally, the logic pulser
and current tracer are used together. A common failure mode for TTL
and CMOS devices is you'll have a node in a circuit stuck low.
Okay, you have a source driving two or more inputs. Who's weighing
everything down? With the circuit in some steady state, start the pulser
pulsing, and apply it to the pin that's the source. Place the tip of
the
current tracer on the trace that the source is attached to, and adjust
the
sensitivity control until the indicator light has some intensity. I
think the
light will blink at some intensity when it's set right-- Anyway, run
the
probe tip along the trace. If the light goes out, or goes dim, you
passed
the branch to where you pulses are going.
You follow the pulses until you end up at the bad device and seriously
impress the hell out of anybody watching.
Why are these things so expensive?
The element at the tip is an *EXTREMELY* sensitive hall-effect device,
it's polarized (notice the little dot on the tip), and it's a seriously
intense
analog instrument in a teeny-weenie little package.
But probably mostly because some people will pay just about anything for
anything that's made by hp (nobody ever got fired for buying an HP
product over something else).
Anyway, so that's the low-down on current tracing (well, as good as I
can remember, anyway). For random-logic, you just cant beat it.
I think I still have an old applications bulletin around here
someplace. . . .
Jeff
On Fri, 09 Oct 1998 18:08:32 -0700 Bruce Lane <kyrrin(a)jps.net> writes:
>At 14:40 09-10-98 -0500, you wrote:
>
>>Holy smokes! You're right! They're not in the 1998 catalog, but I
>found
>>them in the 1996 catalog: HP-547A Current Tracer-- $975 !
>
> <eep!>
>
> My God... I just double-checked the model number on mine.
>
> Yep... 547A. Geez, and I though the Data I/O UniSite I got a
>few years ago
>was a coup!
>
> What makes the darn things so expensive? For that matter, what
>are some of
>the uses for it? I got it mainly as a curiousity, and as part of the
>purchase of my logic pulser, but if the thing is one of those Really
>Useful
>but Obscure tools, I'd like to know about it.
>
>
>-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
>Bruce Lane, Owner and head honcho, Blue Feather Technologies
>(Hamateur: WD6EOS) (E-mail: kyrrin(a)jps.net) (Web:
>http://table.jps.net/~kyrrin)
>SysOp: The Dragon's Cave (Fido 1:343/272, 253-639-9905)
>"Our science can only describe an object, event, or living thing in
>our own
>human terms. It cannot, in any way, define any of them..."
>
___________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
or call Juno at (800) 654-JUNO [654-5866]
El,, I agree about CompuServe, but one of the online services that I know
of in the later 80's was Tandy's PC-Link. It came with DeskMate, and was
text-only (I think). I'm not sure of the prices, because I never signed
up, though. As for graphics, I don't thing there was much graphics. Most
of it was text.
--
-Jason
(roblwill(a)usaor.net)
ICQ#-1730318
----------
> From: Wirehead Prime <wirehead(a)retrocomputing.com>
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: Internet Question
> Date: Friday, October 09, 1998 10:17 PM
>
>
>
> > Does anyone remember the cost of internet access/online time via
Compuserve
> > in the 80s ? I need to give a comparison of today's cost of sending a
> > graphics file.
>
> Er...CompuServe didn't have Internet access in the 80s. For that matter,
> it doesn't really have it in the 90s but that's a matter of opinion. =-D
>
> Anthony Clifton - Wirehead
>
< There's also a version of the UCSD p-System, which runs on a minimal -11
< but that probably has licensing restrictions, too.
Runs nice on -11s but the license it far as I know even more tangled.
Allison
< On this it is my understanding that it was a fairly modified version of
< RT-11, and it won't run on a "real" PDP-11.
Most certainly did. the device drivers supplied are heath specific though
for the disks only.
Allison
Just so everyone knows, Hayes has filed for Bankruptcy..
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
Earlier I poionted out that RT-11 has a hobby license... after rereading
the License it's clear that's not the case it's only available free for
the Supnik Emulator. This doesn't help most people.
Now, the problem is for those people that have an -11 and want to use it
somehow what is there in the way of OSs?
RT-11 legal restrictions exist...
RSX-11 No idea, but I'd expect licensing again
RSTS Licensing again?
Unix... AVAILABLE via PUPs support group as free binaries and 100$
license for sources. Initially this seems good but not all PDP-11
configurations can run unix and not all versions of Unix have the
drivers to interact with some PDP-11 hardware. So it may take a lot
of work with limited tools or none to get it going.
Xenix, available free as binaries for the PRO... Canned version OF V6
by appearance and if you have other than an RD51 it doesn't work.
So what else is there that is free (or very low cost) and can be run on
most of the LSI-11, PDP-11/23 or 11/73 series? IE: can be run on a
11/03 with RX01 floppy or a 11/73 with RQDX3 MSCP disks (hard disks).
There is fuzzball but I know far to little about it or it's applicability
to various hardware configs.
Allison
Some of you might be interested in this great story and remarkable photographs.
>Hello!
>
>I'd be honoured if you include my webpage about the Digital
>PDP8, PDP11 and VAX compatible computers manufactured in Hungary
>during the existance of the "Iron Curtain":
> http://www.internetto.hu/muzeum/e_tpa.html
>
>I also have a PDP-11 tribute page at:
> http://www.telnet.hu/hamster/pdp-11/
>
>Thanks for your time!
>
> / ___ _ _ ___ ____ ___ ___
> /__//__///_///__ / /_ / ) Varga Akos Endre hamster(a)telnet.hu
>/ // // /___/ / /__ / ( www.telnet.hu/hamster/english.html
>----------------------------------------------------------------------
> My collection http://www.telnet.hu/hamster/decadence/e_index.html
>----------------------------------------------------------------------
>
----------------------------------------------------------------------------
-------------------------------
Kevin Stumpf * Unusual systems
+1.519.744.2900 * EST/EDT GMT - 5
Collector - Commercial Mainframes & Minicomputers from
the 50s, 60s, & 70s and control panels and consoles.
Author & Publisher - A Guide to Collecting Computers &
Computer Collectibles * ISBN 0-9684244-0-6
.
< If a sample of those diskettes is available, I, or Allison, or lots of
< others on this list could check it out and find out just what they have
If it's softsector I have capability. If hardsector it's within my
capability. I lack the financial incentive to persue building one
time hardware/software effort being they are an organization.
Allison
