[cctalk] Re: DEC RM03 / CDC 9762

[Michael Thompson via cctalk]

The CDC test system for the RM03 is a standard SMD device. You disconnect the 
Massbus interface and connect the test system where the Massbus interface was 
connected. So the drive interface is probably standard SMD. The data transfer 
of the 9762 is fairly high, so it may not work with slow controllers.

> On Jul 25, 2024, at 5:59 AM, Christian Corti via cctalk 
>  wrote:
> 
> Hello all,
> 
> we now have a RM03 drive, but are missing all the cables and the RH11 
> backplane, though I have the cards.
> Since the drive itself is a CDC 9762 I was wondering if I could ignore the 
> Massbus adapter in the drive cabinet and use the CDC as a "normal" SMD drive 
> (at least it uses the standard 60+26 pin cables).
> There are no service manuals/schematics of the drive itself, so I can't look 
> there. And all I could find on the net were discussions of using the Massbus 
> adapter for normal SMD drives but in my case, I don't want Massbus at all.
> 
> Christian

[cctalk] Re: Papertape-Reader Decitek 442A9: need manual/schematics

[Michael Thompson via cctalk]

Decitek is still in business, so try decitek.com

> On May 16, 2024, at 10:13 AM, Michael Fritsch via cctalk 
>  wrote:
> 
> I have a Decitek 442A9 papertape reader which needs repair.
> 
> I have already replaced the belt, but that is not enough. The reader behaves 
> very strangely. It starts running as soon as I apply power. And there is 
> another problem: when I load a tape, it rattles irregular during reading. 
> This is not a mechanical problem, it seems to react to the pulse of the feed 
> hole, which arrives at the wrong time.
> I'm pretty sure, that I have to adjust the sprockets somehow relative to the 
> stop positions of the stepper motor.
> 
> It was nothing to be found online except pictures of a similar model 443A9 at 
> RICM: 
> https://www.ricomputermuseum.org/collections-gallery/equipment/dec-pdp-8s-4.
> 
> The controller board number is 30291A
> 
> Does anyone happen to have the manual and/or schematics or any other 
> documents?
> 
> Thank you,
> Micha
> 

[cctalk] Re: Random items on Pascal #3

[Michael Thompson via cctalk]

I have a source code tape for Pascal on a CDC 6600 from CDC in France.
I am not sure which version it is.

On Thu, May 9, 2024 at 6:43 PM Chuck Guzis via cctalk 
wrote:

> On 5/9/24 15:10, Fred Cisin via cctalk wrote:
> >>> Turbo-Pascal was quite popular.  At the annnouncement of it (West
> >>> Coast Computer Faire), Phillipe Kahn (Borland) was so inundated with
> >>> "yeah, but what about C?" questions, that by the end of the first
> >>> day, "Turbo C is coming soon"
> >
> > On Thu, 9 May 2024, Sellam Abraham via cctalk wrote:
> >> I learned on Turbo C.  It was a fantastic little IDE.
> >
> > I have heard that Pascal was originally developed for TEACHING
> programming.
> > Turbo Pascal makes that easier.
>
> The first versions of Pascal lacked any I/O specification.
>
> About a decade ago, I retrieved an early version of Pascal (source)
> written on the CDC 6000 from a batch of tapes from UIUC:
>
> (*
>  *   *
>  *   *
>  *COMPILER FOR PASCAL 6000 - 3.4 *
>  *** *
>  *   *
>  *   *
>  * RELEASE 2  MARCH 1976 *
>  *   *
>  *   *
>  *   *
>  *   CDC SCIENTIFIC CHAR SET VERSION *
>  *(00B AND 63B ARE TREATED IDENTICALLY)  *
>  *   *
>  * AUTHOR%   URS AMMANN  *
>  *   INSTITUT FUER INFORMATIK*
>  *   EIDG. TECHNISCHE HOCHSCHULE *
>  *   CH-8006 ZUERICH *
>  *   *
>  *)
>
> Apparently, the collection had a listing, but not machine-readable
> source code. That turned up on one of my tapes, so I forwarded it on.
>
> You can see the whole shebang at
> http://pascal.hansotten.com/niklaus-wirth/cdc-6000-pascal-compilers/
>
> I've written code in Pascal, as well as Modula-2.  Never liked
> it--seemed to be a bit awkward for the low-level stuff that I was doing.
>
> --Chuck
>
>

-- 
Michael Thompson

[cctalk] Re: saving old technology [was: Recordak Magnaprint Microfiche Printer Free]

[Michael Thompson via cctalk]

Most modern Diesel engines use a common-rail electronically controlled 
injection system.

> On May 8, 2024, at 8:58 AM, Paul Koning via cctalk  
> wrote:
> 
> 
> 
>> On May 8, 2024, at 7:56 AM, CAREY SCHUG via cctalk  
>> wrote:
>> 
>> At a local linux meeting, the leader was disparaging any resurrection of old 
>> technology
>> 
>> Anybody else reminded of the science fiction story where ethereal life forms 
>> arrive from a distant star system after receiving our first radio 
>> transmissions.  life that eats radio and electricity, starting with the 
>> frequencies of our first transmissions, but then mutating(?) to all radio, 
>> then electricity even in wires, and wiping out all communications, vehicles, 
>> etc.  There is a desperate project to resurrect steam engines (to build 
>> other steam engines) and breed horses.  All those steam train museums turn 
>> out to be what saves humanity.  just now I realized..shouldn't they also 
>> consume all the light too?  But I guess they can't go beyond microwaves.
> 
> "The Waveries" by Fredric Brown, 1945.  Never mind the bit about light; the 
> author missed the fact that Diesel engines don't need electricity, and also 
> the fact that thunder can't happen without lightning.
> 
>paul
> 

[cctalk] Re: Other input devices.

[Michael Thompson via cctalk]

> > On Apr 12, 2024, at 9:55 PM, ben via cctalk 
> wrote:
> >
> > Did any one ever use a keyboard to magtape as input device?
>
> My wife did, sort of: for a while she worked with IBM MT/ST word
> processors.  Those were very early word processing systems that used a
> custom magnetic tape cartridge for storage and a Selectric typewriter for
> I/O.
>
> paul
>
>
The Rhode Island Computer Museum has two IBM Mag Card Selectric systems,
and just got an IBM Cassette Selectric System.
-- 
Michael Thompson

[cctalk] Re: Cleanup time again

[Michael Thompson via cctalk]

Clean the connectors and reseat the socketed chips and it will probably work.

> On Apr 11, 2024, at 1:55 PM, Bill Gunshannon via cctalk 
>  wrote:
> 
> 
> 
> One last shot.
> 
> I have an RX Floppy disk unit.  Worked fine until one
> time the last time I had it hooked  up and after about
> an hour it just stopped responding.  All I get now is
> the well known click-click on init and then nothing. I
> am sure it is repairable either by troubleshooting or
> just buying another boardset.
> 
> Anybody interested?  I imagine a number of people  here
> will be driving by not far from my home on their way back
> from VCF.
> 
> bill

[cctalk] Re: PDP-11 thingy. What is it?

[Michael Thompson via cctalk]

The backplane says that it is for a PDP-11/03
The chassis is missing the power supply.

The M8189 is a  PDP-11/23+ KDF11-B PDP-11 CPU

The FC202 is a Charles River Data Floppy Diskette board
https://shop-pdp.net/~stuff/Pictures/index.php?dslct=/CRDS_FC-202_Floppy_Disk_Controller=0=0=0

On Wed, Apr 10, 2024 at 7:14 PM W2HX via cctalk 
wrote:

> Hi all, I picked up this PDP-11 thing. Can anyone help me understand what
> it is?
> Pictures are here:
> https://w2hx.com/?prefix=x/What-Is-It/PDP-11-Thing/
>
> I could not find any designation on the backplane. It is a wire-wrappable
> backplane. I don't know if it is Qbus, unibus or whether it is 18 or 22 bit
> addressing (this is because I am a newbie in this area).
>
> There is only one board with a number on it, the M8189 board. I know that
> is a fonz-11 board.
> https://w2hx.com/?prefix=x/What-Is-It/PDP-11-Thing/M8189/
>
> There are two other boards with no designation on them. Does anyone
> recognize them?
> This first one seems to have no "big chips" on it. But it has two
> connectors that seem to allow another dual-height card to be plugged into
> it. What is it?
> https://w2hx.com/?prefix=x/What-Is-It/PDP-11-Thing/Board1/
>
> The second one has this 50 pin IDC connector on it. Anyone recognize it?
> https://w2hx.com/?prefix=x/What-Is-It/PDP-11-Thing/Board2/
>
> Any info appreciated!
>
> 73 Eugene W2HX
> My Youtube Channel: https://www.youtube.com/@w2hx/videos
>
>

-- 
Michael Thompson

[cctalk] Re: oscilloscopes

[Michael Thompson via cctalk]

DEC used Tektronix R503 scopes for a display on many of their early
machines.

On Wed, Apr 3, 2024 at 11:16 AM Paul Koning via cctalk <
cctalk@classiccmp.org> wrote:

>
>
> > On Apr 3, 2024, at 11:01 AM, Guy Fedorkow via cctalk <
> cctalk@classiccmp.org> wrote:
> >
> > Vintage computer enthusiasts might want to keep track of where to find
> CRT-based analog oscilloscopes, for use as output devices.
> > The early MIT and Lincoln Labs computers used D/A converters to steer
> and activate the beam on analog scopes to draw vector images.
> > Working on Whirlwind simulation, we've been able to get this technique
> to work with "real" oscilloscopes, e.g., Tek 475, but we have not yet found
> a single DSO that has X/Y _and_ Z inputs (let alone the required phosphor
> fade).
>
> So did a whole range of DEC computers, of course.  And the famous CDC
> mainframe console (DD60) though it did vectors only for text (graphics was
> dot-mode only since it wasn't a major use case for that device).
>
> I once built a graphics display setup for an 11/20 lab machine (in
> college) using DEC D/A modules (AA-01?) with an RC-11 disk serving as the
> refresh memory, DMA direct to the D/A data register.
>
> paul
>
>
>

-- 
Michael Thompson

[cctalk] Re: DEC Processor Books

[Michael Thompson via cctalk]

A photographer wandered around my workplace looking at all of the men's
hands. They were doing a closeup shot and needed just hands. More than a
little strange.

On Mon, Mar 18, 2024, 6:15 AM Norman Jaffe via cctalk 
wrote:

> I had the same experience while working for a (very) small company called
> Northwest Digital Research.
> I was asked to point to a big HP plotter that was running one of our
> programs... and the photograph wound up in our product brochure.
> Of course, I had nothing to do with that program...
>
> From: "Mark Linimon via cctalk" 
> To: "General Discussion: On-Topic and Off-Topic Posts" <
> cctalk@classiccmp.org>
> Cc: "Mark Linimon" 
> Sent: Sunday, March 17, 2024 5:43:13 PM
> Subject: [cctalk] Re: DEC Processor Books
>
> > were just DEC employees that caught somebody's eye when they were
> > planning the shots.
>
> "Planning" may assume facts not in evidence :-)
>
> Some photographers wandered around my employer of the time, Recognition
> Equipment. (Like my Canadian girlfriend, you haven't heard of it.)
> I was near enough to a piece of machinery to be told "point to
> that console like you are doing something to it". So somewhere
> in some ancient Annual Report you can find a picture of a clean-
> shaven me. My 15 seconds of fame.
>
> Well maybe not all 15.
>
> So the "plan" was, we're on deadline, get some shots.
>
> mcl
>

[cctalk] Re: DEC Processor Books

[Michael Thompson via cctalk]

Some of the pictures were staged in a parking lot. They probably didn’t have a 
room big enough.

> On Mar 17, 2024, at 10:55 AM, Paul Koning via cctalk  
> wrote:
> 
> 
> 
>> On Mar 17, 2024, at 10:13 AM, Bill Gunshannon via cctalk 
>>  wrote:
>> 
>> 
>> I have often wondered about the people we find in the various
>> DEC Processor (and other) books.  Were they models in staged
>> photo-sessions or were these candid shots from DEC facilities
>> and if so, can anyone identify who they might be.
> 
> I don't know any specifics, but they generally look like staged sessions to 
> me.  Most of those pictures are far too clean looking to be typical DEC 
> facilities, and the people in them are generally dressed too nice for the 
> typical DEC workplace as well.  
> 
> Some look like they might be set up at DEC training sites (like the one in 
> Bedford, MA near Mitre), that's about the only place I could think of where 
> you'd see a nice looking arrangement of hardware and people dressed in suits 
> and ties.
> 
>paul
> 
> 

[cctalk] Re: Qume 842 8" Disk Drive Question

[Michael Thompson via cctalk]

Connect an oscilloscope to the output of the single-sided sensor and see if
it works. If so, trace the signal through the logic and see if it gets to
the I/O connector that goes to the greaseweazel.

On Wed, Jan 31, 2024 at 2:38 PM Mike Katz via cctalk 
wrote:

> I have recently acquired a Qume Model 842 double sided 8" disk drive.
>
> I have reset all of the settings to factory default and hooked it up to
> my greastweazle.
>
> The drive works perfectly for double sided disks (using the appropriate
> index hole).
>
> However, the greaseweasel reports no index pulse when I put a single
> sided diskette in the drive.  I have attempted to clean out the sensor
> for single sided diskettes to on avail.
>
> Does any one have any ideas?
>
> The grease weasel works perfectly when I connect SA-800 drives.
>
> I have not yet tried installing terminating resistors in the Qume.
>
> Thank you in advance for your help,
>
>Mike
>
> On 1/31/2024 12:56 PM, Martin Bishop via cctalk wrote:
> > Ah, PPC VME cards, add VXworks, funky coprocessors, COTS IO and you have
> definitely got something best avoided : details would involve libations.
> >
> > The conduction cooled chassis are OK and worth repurposing.
> Contrariwise the VME bus is best avoided, whether classic 32b VME or the 64
> bit revision.  However, the connectors for VME 64x backplanes and the form
> factor have merit, but that is to depart from the past.
> >
> > Martin
> >
> > -Original Message-
> > From: Wouter de Waal via cctalk [mailto:cctalk@classiccmp.org]
> > Sent: 31 January 2024 18:34
> > To: cctalk@classiccmp.org
> > Cc: Wouter de Waal 
> > Subject: [cctalk] Re: Vmebus
> >
> >
> >> Anyone have a VMEbus system they use at least occasionally? If so, what
> >> make/model/config?
> > I still use a couple of PPC VME boards (DY4 / Curtiss Wright
> 182/183/184, both Conduction-Cooled and Air-Cooled) to test the tail end of
> hardware that we are still shipping (by now EOL and basically NOS).
> >
> > But it's work, I don't find them interesting.
> >
> > If someone here has the warm fuzzies for PPC VME, we can talk :-)
> >
> > W
> >
>
>

-- 
Michael Thompson

[cctalk] Re: Vmebus

[Michael Thompson via cctalk]

I have a Sun3E VMEbus system. It is a Sun3/60 split into five 6Ux160 VMEbus
boards.

On Wed, Jan 31, 2024 at 8:57 AM Bill Degnan via cctalk <
cctalk@classiccmp.org> wrote:

> Sorry, that is the old FAQ and may not be correct, here is a newer page
> https://classiccmp.org/mailman3/postorius/lists/cctalk.classiccmp.org/
>
> On Wed, Jan 31, 2024 at 7:11 AM Kevin Lee via cctalk <
> cctalk@classiccmp.org>
> wrote:
>
> > Unsubscribe me from this list.
> >
> >
> >
> > On Wed, Jan 31, 2024, at 12:14 PM, Tom Ivar Helbekkmo via cctalk wrote:
> > > Bill Degnan via cctalk  writes:
> > >
> > > > Anyone have a VMEbus system they use at least occasionally? If so,
> what
> > > > make/model/config?
> > >
> > > I have a couple of old Stride Micro systems, a 440 and a 460, that get
> > > turned on very occasionally.  They run UniStride 2.1, which is based on
> > > SVR2, if memory serves.  Nice 68010-based machines, interesting
> software
> > > architecture, with an advanced BIOS that supports several operating
> > > systems, and can even run multiple OS-es simultaneously.
> > >
> > > -tih
> > > --
> > > Most people who graduate with CS degrees don't understand the
> > significance
> > > of Lisp.  Lisp is the most important idea in computer science.  --Alan
> > Kay
> > >
> >
>


-- 
Michael Thompson

[cctalk] Re: 11/15, 11/20 systems and parts, more

[Michael Thompson via cctalk]

The RICM got a complete 11/20 donation a few weeks ago, so we no longer
need parts to complete the empty chassis.

On Sun, Jan 28, 2024, 11:37 PM Paul Anderson via cctalk <
cctalk@classiccmp.org> wrote:

> A quick update: The seller and I have not been able to reach a deal on any
> of this. He is looking for ebay or higher prices, and nothing is complete.
> It appears it is bits and pieces leftover from scrapping years ago.
>
> Thanks, Paul
>
> On Wed, Oct 18, 2023 at 8:56 PM Paul Anderson  wrote:
>
> > I am working on a deal which includes several PDP11/15 or 20s. I will be
> > looking at them next week and hope to get more details. I will look for
> > exact model numbers and configuration.At least 2 of them have non DEC
> > silkscreens on the front panel.
> >
> > Also a selection of 11/05 and 11/10 including 5 1/4 box, BA11-D, and
> > BA11-K units.
> >
> > If you are interested in a box or parts please email me off list.
> >
> > Thanks, Paul
> >
>

[cctalk] Re: Anyone have a D1 deck?

[Michael Thompson via cctalk]

You could contact https://www.wmbt.org/ to see if they have a Bosch or Sony DEC 
to read the tapes.

> On Dec 31, 2023, at 8:58 PM, Zane Healy via cctalk  
> wrote:
> 
>> On Dec 31, 2023, at 1:42 PM, The Doctor via cctalk  
>> wrote:
>> 
>> On Saturday, December 30th, 2023 at 23:24, Chuck Guzis via cctalk 
>>  wrote:
>> 
>> The Bosch unit may be very difficult to find. Will a Sony
>>> DVR-1000/2000/2100 do the same job for those tapes? At least a few of
>>> those seem to be around.
>> 
>> None of us are sure.  The Sony DVR units have been pretty easy to find but
>> the possibility of messing up any of the tapes even as a test ties everything
>> in a knot.  I know a few folks are asking around the A/V offices of a couple
>> of colleges to see if they have any suitable playback units but so far 
>> nothing
>> yet (due to semester break).
>> 
>> The Doctor [412/724/301/703/415/510]
>> WWW: https://drwho.virtadpt.net/
>> Don't be mean. You don't have to be mean.
> 
> If there is money to fund this effort, it might be worth talking to Iron 
> Mountain, to see if they can handle the media.  They have people that do this 
> sort of thing, AND, I know for a fact they have hardware to handle some 
> strange formats.
> 
> Zane
> 
> 

[cctalk] Re: 11/15, 11/20 systems and parts, more

[Michael Thompson via cctalk]

I think a complete system would be worth more than the sum of its parts.

On Mon, Oct 30, 2023, 3:27 AM Paul Anderson via cctalk <
cctalk@classiccmp.org> wrote:

> Hi Michael,
>
> I might be able to part out a system. Any idea what one is worth?
>
> Paul
>
> On Fri, Oct 20, 2023 at 3:58 AM Michael Thompson via cctalk <
> cctalk@classiccmp.org> wrote:
>
> > The RICM has an empty 11/20 chassis and the power supply. All it needs is
> > the processor backplanes. Is there any chance you have a set of
> backplanes
> > available?
> >
> > On Fri, Oct 20, 2023, 2:35 AM devin davison via cctalk <
> > cctalk@classiccmp.org> wrote:
> >
> > > I have a few systems in rough shape, and need parts. Let me know what
> you
> > > find, i am interested. I mainly run my unibus 11/34 systems, but i
> have a
> > > few q bus syatems in need of parts and repair.
> > >
> > > Thanks,
> > >
> > > Devin D.
> > >
> > > On Thu, Oct 19, 2023, 8:02 PM Mark Linimon via cctalk <
> > > cctalk@classiccmp.org>
> > > wrote:
> > >
> > > > I sincerely doubt I could afford a PDP-11/20 but I still have
> nostalgia
> > > > for the first machine I used at university.  So I have to ask.
> > > >
> > > > mcl
> > > >
> > >
> >
>

[cctalk] Re: 11/15, 11/20 systems and parts, more

[Michael Thompson via cctalk]

The RICM has an empty 11/20 chassis and the power supply. All it needs is
the processor backplanes. Is there any chance you have a set of backplanes
available?

On Fri, Oct 20, 2023, 2:35 AM devin davison via cctalk <
cctalk@classiccmp.org> wrote:

> I have a few systems in rough shape, and need parts. Let me know what you
> find, i am interested. I mainly run my unibus 11/34 systems, but i have a
> few q bus syatems in need of parts and repair.
>
> Thanks,
>
> Devin D.
>
> On Thu, Oct 19, 2023, 8:02 PM Mark Linimon via cctalk <
> cctalk@classiccmp.org>
> wrote:
>
> > I sincerely doubt I could afford a PDP-11/20 but I still have nostalgia
> > for the first machine I used at university.  So I have to ask.
> >
> > mcl
> >
>

[cctalk] Re: Comparing PDP-8 processor flipchip

[Michael Thompson via cctalk]

I have seen lots of small differences between machines with no real explanation 
of why.

> On Sep 12, 2023, at 10:11 AM, Bill Degnan via cctalk  
> wrote:
> 
> The recent Ebay auction for the original PDP-8 got my attention because one
> of the photos (the processor logic flipchip array) is a nice snapshot for
> comparison purposes with the system I am working on.
> 
> https://vintagecomputer.net/digital/pdp-8/PDP-8_flip-chips_left.png (mine)
> https://vintagecomputer.net/temp/EBAYPDP-8ProcessorFlipchips.jpg
> 
> Given my PDP-8 is close to working, I would assume that the Ebay PDP-8
> would have a fighting chance, at least as far as the flip chip
> configuration goes.  This is also a nice confirmation that I more or less
> have the flipchips in the right places.  There are only a few slight
> differences.
> 
> Bill

[cctalk] Re: Apple 1

[Michael Thompson via cctalk]

>  No one collects cloud servers, the things that do
> the real work and storage.  Will they?

Google's first server is in the Computer History Museum...

On Sat, Aug 5, 2023 at 8:54 AM Bill Degnan via cctalk 
wrote:

> Something has to be the most sought-after thing in every collectors'
> hobby.  The Apple I is not historically significant enough alone to justify
> the prices they get, there is a cultural/memorabilia component too.  Just
> rare enough to form an elite "market".  It's an indicator that computer age
> collecting is healthy and robust.  The Apple I prices help support all
> vintage computer prices, if you're into all that.
>
> I have noticed, from running an indie computer museum for 4 years, that
> young people dont know much about 8-bit computers.  They're much more
> interested in SGIs and NeXT and DOS gamers with a mouse GUI.
>
> Fast forward 50 years.  Impossible to know how society will rememeber the
> computer age, roughly 1950-2000.  A lot of kids today dont lust after a
> computer like prior 4  generations, their smartphone and school-issued
> chromebooks are just fine.   Most people today own computers that are
> nothing more than a network interfaces. We in this group are atypical,
> archaic by definition. No one collects cloud servers, the things that do
> the real work and storage.  Will they?  Not sure what you call it but we're
> not in the "computer age" anymore.  My point, the memorabilia factor that
> supports Apple I prices will drop off, leaving only the historic value.
> Will the historic value support current prices?  A market requires demand.
> What will be the demand in 2073?
>
> Historians will always value the Apple I and a few others from the computer
> age, but the price escalation phase of probably over.
>
> One would still have to pay the future value equivalent of $250,000+ for an
> Apple I for as long time.  Few if any other computers from our era will
> earn anything close to those prices.
>
> Bill
>
> On Fri, Aug 4, 2023, 2:03 PM Peter Corlett via cctalk <
> cctalk@classiccmp.org>
> wrote:
>
> > On Fri, Aug 04, 2023 at 08:51:31AM -0500, John Herron via cctalk wrote:
> > [...]
> > > That price is interesting. Does that imply the value has gone down
> after
> > > some skyrocketed close to 1 million? One still has to make the decision
> > of
> > > a owning a house or an apple 1.
> >
> > Well, both of them are treated as speculative investments, putting them
> out
> > of reach of people who just want the pleasure of using them rather than
> > looking for the next bagholder. The main difference is that I can just
> buy
> > the parts to build my own Apple 1 and nobody's going to stop me, whereas
> if
> > I try that with a house the local authority gets quite upset.
> >
> >
>


-- 
Michael Thompson

Re: Comtec model P135-20/35 Paper Tape Punch

[Michael Thompson via cctalk]

Comtec was a tiny Rhode Island company that was owned by the family that
used to live across the street from me. The RICM has a PDP-8/L powered
document scanner that has a Comtec paper tape reader inside. Comtec was
eventually bought by Zebra, another Rhode Island company that started out
making badge printers.

-- 
Michael Thompson

Re: DECTape head problem

[Michael Thompson via cctalk]

>
>
> Date: Tue, 8 Feb 2022 20:55:31 +
> From: Wayne S 
> Subject: Re: DECTape head problem
>
> So it serms dectape heads are special. I don?t think Dec would have the
> desire to make them internally so they probably contractef with a company
> already set up to do that. Who were the big tape head manufacturers at that
> time? Does anyone know?
>

We have one from Applied Magnetics Corporation, maybe the one in Goleta, CA.

-- 
Michael Thompson

Re: DECTape head problem

[Michael Thompson via cctalk]

DECtapes have 5x redundant tracks. If you could find an 8-track head that
had the same track pitch, and maybe track width, you could read the tape
but lose redundancy on the Mark and Timing tracks. That probably would not
work with a marginal DECtape.

On Mon, Feb 7, 2022 at 3:33 PM Wayne S  wrote:

> I’ve often wondered if the tape heads from consumer tape devices such as
> cassette or 4-8 track tape players could be used or be made to be used as
> replacements. Anybody ever try that?
>
> Sent from my iPhone
>
> > On Feb 7, 2022, at 11:51, Michael Thompson via cctech <
> cct...@classiccmp.org> wrote:
> >
> > 
> >>
> >>
> >> From: Gary Oliver 
> >> Subject: DECTape head problem
> >>
> >> In debugging my DECtape interface lashup, I found that one of my head
> >> has two open windings.? Specifically, one channel has an open 'ground'
> >> with the other two lines apparently the full winding of the channel.?
> >> The second channel failing has no continuity between any of the three
> >> lines.? I have tested the other head and it has all the requisite
> >> continuity so I'm hoping I can at least get a single spindle running.
> >>
> >> Has any ever attempted repair of one of these?
> >>
> >> -Gary
> >>
> >
> > At the Rhode Island Computer Museum we found several DECtape heads on
> TU55
> > and TU56 drives with open connections. A volunteer got one head X-Rayed
> so
> > we could see the solder joints between the tiny wires for the head coils,
> > and the larger twinax wires that go to the relay board. We couldn't see
> any
> > damage to the wires or solder joints.
> >
> > We tried heating the potting material to soften it, and digging it out to
> > get to the solder joints. While digging at the potting material you can't
> > see the tiny wires, so they will likely get damaged.
> >
> > We considered using a solvent to remove the potting material, but thought
> > that it would eat the enamel off the head coil wires and damage them
> beyond
> > repair.
> >
> > So far we haven't found a way to repair the heads.
> >
> > Michael Thompson
>


-- 
Michael Thompson

Re: DECTape head problem

[Michael Thompson via cctalk]

>
> From: Gary Oliver 
> Subject: DECTape head problem
>
> In debugging my DECtape interface lashup, I found that one of my head
> has two open windings.? Specifically, one channel has an open 'ground'
> with the other two lines apparently the full winding of the channel.?
> The second channel failing has no continuity between any of the three
> lines.? I have tested the other head and it has all the requisite
> continuity so I'm hoping I can at least get a single spindle running.
>
> Has any ever attempted repair of one of these?
>
> -Gary
>

At the Rhode Island Computer Museum we found several DECtape heads on TU55
and TU56 drives with open connections. A volunteer got one head X-Rayed so
we could see the solder joints between the tiny wires for the head coils,
and the larger twinax wires that go to the relay board. We couldn't see any
damage to the wires or solder joints.

We tried heating the potting material to soften it, and digging it out to
get to the solder joints. While digging at the potting material you can't
see the tiny wires, so they will likely get damaged.

We considered using a solvent to remove the potting material, but thought
that it would eat the enamel off the head coil wires and damage them beyond
repair.

So far we haven't found a way to repair the heads.

Michael Thompson

Re: 11/785 on ebay (2018) - was Re: VAX 780 on eBay

[Michael Thompson via cctalk]

>
>
> Date: Mon, 3 Jan 2022 11:39:01 -0500
> From: Chris Zach 
>
> The thing that always made me wonder is where are all the 8600's. The
> 8600 was apparently the best selling large Vax, outselling the 780 and
> 750, so what happened to all of them? They weren't any bigger than a 780...
>
> C
>

There is an 8650 at the RICM.
https://www.ricomputermuseum.org/collections-gallery/equipment/dec-vax-8650

-- 
Michael Thompson

Re: Source for DEC TC01 (and similar) bulbs?

[Michael Thompson via cctalk]

On Sun, Dec 5, 2021 at 11:46 PM Josh Dersch  wrote:

> I swapped boards around in the datapath for these bits on the TC01 side
> last night and the problem doesn't move.  On a whim I put my thumb on the
> tape as it passes over the head and it seems to affect the glitchiness of
> the data, at times making it appear to go away entirely.  Doesn't appear to
> be a tape tension problem -- it seems adequate and putting my thumb on the
> supply reel to increase tension a bit does not have the same effect.  This
> would seem to point to the TU55 being the issue, and quite possibly the
> heads.  I haven't had time today to look at the signals coming off the
> heads but I plan to soon.
>
> Thanks for the help!
> - Josh
>

I would measure the resistance of the head coils at the relay board
connector. Hopefully they all measure about the same. Figure 2-2 in the
maintenance manual shows how the MARK and DATA tracks are wired, and the
extra connection available for the TIMING track. We found a head on the
PDP-9 where the +D0 connection was open.

-- 
Michael Thompson

Re: Source for DEC TC01 (and similar) bulbs?

[Michael Thompson via cctalk]

>
>
> From: Josh Dersch 
> Subject: Source for DEC TC01 (and similar) bulbs?
>
> The Search Scope loop diagnostic shows block numbers going by in both
> directions so a lot of the drive and controller are working, but there's
> some glitchiness in bits 2, 5, 8, and 11 of the data so I need to trace
> that down; I hope it's not the tape head.
>
> - Josh
>

 So what do bits 2, 5, 8, & 11 have in common? All bits come from the same
track on the tape head, and share some of the path to the Data Buffer.

If you wrote this tape on this system, I would try reading a tape that was
written on another machine to make sure that the problem didn't originate
with writing.

Check for a bad connection where the tape head cable connects to the G851
module in the TU55, where the G851 plugs into the TU55 backplane, and where
the data cable plugs into the TU55 backplane, and possibly the K2 relay on
the G851.

In the TC01 you could swap the G888 module in slot C22, the S205 module in
slot D05, the S205 module in slot E06, the S603 module in slot C02, or the
R123 module in slot E08, with another one to see if the glitch moves to
another bit.

-- 
Michael Thompson

Re: Sun-2 and Sun-3 mice (eBay)

[Michael Thompson via cctalk]

>
> AFAIK, the posts are there so you don't plug your mouse into a phone
> jack or a modem port.  There are cutouts on the back of the Sun3
> keyboard to admit that connector.
>

My Sun 2/120 server has an RJ mouse connector next to the RJ keyboard
connector on the back of the chassis.

My Sun 2/50 desktop client has a DA-15 keyboard connector on the back and
has the mouse plugged into the keyboard.

I have a black Mouse Systems mouse with a Sun sticker on the front. P/N
900783-002/01. Maybe for a Sun-1?

-- 
Michael Thompson

Re: Looking for VAX6000 items (Paul Koning)

[Michael Thompson via cctalk]

I believe that the CDC built RP04 has a three-phase spindle motor.

> On Jul 15, 2021, at 5:13 PM, Paul Koning  wrote:
> 
> 
> 
>> On Jul 15, 2021, at 4:33 PM, Michael Thompson 
>>  wrote:
>> 
>> The power cord is three-phase, and actually daisy-chains to a second and 
>> third drive. The phases on the AC output connector are rotated to balance 
>> the load on all three phases when three drives are daisy-chained. If you 
>> look at the power wiring diagram on page 3-120 of the Memorex 677-01 manual 
>> you will see only two of the phases going to the power transformer.
> 
> Ok.  I just looked up the RP04 maintenance manual.  It isn't all that 
> explicit but it does say that the spindle motor is a 3-phase induction motor.
> 
>paul
> 

Re: Looking for VAX6000 items (Paul Koning)

[Michael Thompson via cctalk]

The power cord is three-phase, and actually daisy-chains to a second and
third drive. The phases on the AC output connector are rotated to balance
the load on all three phases when three drives are daisy-chained. If you
look at the power wiring diagram on page 3-120 of the Memorex 677-01 manual
you will see only two of the phases going to the power transformer.

On Thu, Jul 15, 2021 at 4:22 PM Paul Koning  wrote:

>
>
> > On Jul 15, 2021, at 4:19 PM, Michael Thompson via cctech <
> cct...@classiccmp.org> wrote:
> >
> >>
> >> From: Paul Koning 
> >> To: Chris Zach , "cctalk@classiccmp.org"
> >>
> >> Subject: Re: Looking for VAX6000 items
> >>
> >> A number of the large disk drives use 3 phase motors; RP04/5/6 are
> >> examples as well.
> >>
> >> Three phase motors won't run on single phase power without help from run
> >> capacitors.  (There is no such thing as "two phase power" -- 220 volts
> is
> >> single phase, balanced.)
> >>
> >>paul
> >>
> >
> > The RP06 uses 220VAC single phase motors for the spindle and blower.
>
> Interesting.  I distinctly remember a disk drive installation manual that
> warned about phase order.  Perhaps that was for the RP04 and not the RP05/6
> ?
>
> paul
>
>

-- 
Michael Thompson

Re: Looking for VAX6000 items (Paul Koning)

[Michael Thompson via cctalk]

>
> From: Paul Koning 
> To: Chris Zach , "cctalk@classiccmp.org"
> 
> Subject: Re: Looking for VAX6000 items
>
> A number of the large disk drives use 3 phase motors; RP04/5/6 are
> examples as well.
>
> Three phase motors won't run on single phase power without help from run
> capacitors.  (There is no such thing as "two phase power" -- 220 volts is
> single phase, balanced.)
>
> paul
>

The RP06 uses 220VAC single phase motors for the spindle and blower.

I converted an RP06 from three-phase to single-phase to use with PDP-10
KS10 at home. Instructions are here:
https://sites.google.com/site/mthompsonorg/Home/pdp-10/rm03-and-rp06-information/rp06

-- 
Michael Thompson

Re: PDP-8/I Negative-bus termination

[Michael Thompson via cctalk]

>
> Date: Wed, 5 May 2021 00:03:05 -0700
> From: Josh Dersch 
> Subject: PDP-8/I Negative-bus termination
>
> Hey all --
>
> Until this point I've never had any peripherals for my negibus systems
> (apart from teletypes), and it occurs to me that I have no idea if the bus
> needs to be terminated (and if so, with what).  There are 6 slots in the
> RF08 backplane (D01-D06) for daisy-chaining to the next device, which is
> where I assume they'd go; the RF08 manual does not make it clear what this
> looks like or if it's actually required, and I've gone through the
> available PDP-8/I docs and I'm still at a loss.
>
> Can anyone with negibus experience point me in the right direction?
>
> Thanks,
> Josh
>

The DEC Field Service Technical Manual has some notes on bus termination.
It says:

Termination is required on I/O cables longer than 20 ft., and may be
desirable on shorter cables. For negative bus, use 220 Ohm shunt resistors
to ground on IOP 1, IOP 2, IOP 4, BTS 1, BTS 3 and Initialize. No special
termination module exists for the negative bus.

-- 
Michael Thompson

Re: Motor generator

[Michael Thompson via cctalk]

>
> Date: Wed, 5 May 2021 13:20:59 +0100
> From: 
> Subject: RE: Motor generator
>
> We had a Motor/Generator for our Honeywell L66. Not sure it was because it
> wanted US voltages or just for a clean supply
> Dave
>

I also worked on a Honeywell L66 that had two motor-generators. We used one
at a time, and swapped the operational one each month. They cleaned up the
noise in the incoming 208VAC 3-phase power, and the really heavy flywheel
provided a little ride through for short term power drop outs.

-- 
Michael Thompson

Re: IBM 1410 FPGA Implementation Update - new github repository

[Michael Thompson via cctalk]

>
> Date: Sun, 2 May 2021 15:38:33 -0500
> From: Jay Jaeger 
> Subject: IBM 1410 FPGA Implementation Update - new github repository
> Message-ID: <68c06711-e563-f1bf-8abc-090793bed...@charter.net>
>
> The last 12 months I have been pretty busy working on my 1410 in FPGA
> project, and there is now more to share, though I have not done much
> actual work since February - been too busy playing with other "toys".  8D
>
> JRJ
>

The RICM has a 1401 control panel. It would be pretty cool to mount your
FPGA to the back of it and get it to blink the lights the right way.

https://www.ricomputermuseum.org/Home/interesting_computer_items/ibm-control-panels

-- 
Michael Thompson

Re: DEC RF08/RS08 module placement info

[Michael Thompson via cctalk]

I sent Josh pictures of the complete RF08/RS08 that John Wilson donated to
the RICM. I will send detailed pictures of the RS08<->RF08 cables next week.

-- 
Michael Thompson

Re: DEC PDP-11/45 backplane +5 ECO

[Michael Thompson via cctalk]

>
>
> On 4/24/21 10:28 PM, Noel Chiappa via cctalk wrote:
> >   Noel
> >
> > PS: I wonder how many people here have -11/45's? ISTR one other, but
> they aren't
> > common.


The Rhode Island Computer Museum has two. The pair were the interface
between fire pull boxes and the 911 dispatch system in Brooklyn, NY. Both
have DV11 & DH11 serial controllers. These are capable of the very low baud
rates needed to talk to the fire pull boxes.

https://www.ricomputermuseum.org/collections-gallery/equipment/dec-pdp-11-45

--
Michael Thompson

Re: DECtape ancestry (Kyle Owen)

[Michael Thompson via cctalk]

>
> Date: Sat, 20 Mar 2021 16:21:44 -0400
> From: Kyle Owen 
> Subject: Re: DECtape ancestry
>
> What systems took advantage of the bidirectional nature?
>
> Kyle
>

ADSS on the PDP-9 does an interleave of 6 when reading/writing to the
DECtape. If it runs off the end it reverses direction and keeps going. I
have seen some library files take three passes of the DECtape to fully
search.

-- 
Michael Thompson

Re: Massbus - was: Re: VAX 11/750

[Michael Thompson via cctalk]

The PDP-10 KL10 at the RCS/RI was used to control a real-time flight
simulator at Sikorski. It had one of the RH20 Massbus controllers connected
to a DTR01 cabinet holding a DR01 chassis. The DR01 was, I think, connected
to a DR11 chassis that had A/D and D/A converters boards inside. You could
use the same DTR01 subsystem to connect two PDP-10s together with Massbus,
or connect a PDP-10 to a PDP-11 with Massbus.

-- 
Michael Thompson

Re: Flip-Chip selloff (Al Kossow)

[Michael Thompson via cctalk]

>
>
> Date: Tue, 2 Feb 2021 09:19:08 -0800
> From: Al Kossow 
> Subject: Flip-Chip selloff
>
> I don't have any equipment that uses them any more, so I'll be ebaying off
> my
> A-W series flip chips over the next few days. The W's and PT08 boards are
> up now
>
> https://www.ebay.com/itm/184647476832
> https://www.ebay.com/itm/184647420812
>

I am still maintaining a PDP-8/I & TC01, PDP-8/L, PDP-8/S, PDP-9 & TC02,
and PDP-12 for the Rhode Island Computer Museum.

The RICM would happily accept any donated FlipChips, especially the go-fast
B versions and anything else for the PDP-9. You can even get a charitable
tax deduction for the donation.

-- 
Michael Thompson

Re: Sun/3-powered 737 flight sim

[Michael Thompson via cctalk]

I have also seen the SCSI terminator power fuse blow when the terminator is
hot plugged.

On Mon, Aug 17, 2020 at 7:26 PM Chris Hanson 
wrote:

> On Aug 17, 2020, at 10:52 AM, Michael Thompson via cctalk <
> cctalk@classiccmp.org> wrote:
> >
> > I have a Sun 3/E, including a SCSI/Ethernet board, that ran fine the last
> > time it was powered on. There is a collector in southern Germany who also
> > has a 3/E board set. I didn't see any contact information for the
> simulator
> > owners.
>
> The originator of the Reddit thread works on this simulator and is the
> point of contact.
>
> They're really interested in moving off the Sun 3/e rather than continuing
> to try to get spare parts etc. I've also suggested they check the
> capacitors and fuses, especially on the Ethernet/SCSI cards, since the
> originator claims multiple failures. The Ethernet fuse in particular is
> likely very easy to trip because people these days aren't used to AUI
> adapters which generally *can not* be hot-plugged without blowing a fuse.
>
>   -- Chris
>
>

-- 
Michael Thompson

Re: Sun/3-powered 737 flight sim

[Michael Thompson via cctalk]

>
> Date: Mon, 17 Aug 2020 00:22:52 -0700
> From: Brendan Shanks 
> Subject: Sun/3-powered 737 flight sim
>
> Something that I thought the folks here would appreciate: a fellow in
> Dubai is trying to keep a full-motion Boeing 737-300 sim (from 1991)
> running.
> The main host machine is a Sun/3E, connected over Ethernet to the operator
> workstation which has 2 Sun/3Es each with a cgtwo powering a CRT touch
> screen. One of the Sun VME SCSI/Ethernet boards died, and he?s been unable
> to find a (working) replacement board.
>
> There?s also a big rack of Concurrent hardware running OS/32, and some
> newer PCs for visuals and TCAS.
>
> Plenty of pictures and a video tour of all the hardware at:
> <
> https://www.reddit.com/r/BSD/comments/i8c8u7/how_do_i_emulate_a_sun_3e_computer_with_5018027/
> <
> https://www.reddit.com/r/BSD/comments/i8c8u7/how_do_i_emulate_a_sun_3e_computer_with_5018027/
> >>
>
> Brendan
>

I have a Sun 3/E, including a SCSI/Ethernet board, that ran fine the last
time it was powered on. There is a collector in southern Germany who also
has a 3/E board set. I didn't see any contact information for the simulator
owners.

-- 
Michael Thompson

Re: Burroughs L-series paper tapes

[Michael Thompson via cctalk]

There is a B800 at the RICM, but nothing larger.


> On Aug 5, 2020, at 1:00 PM, cctech-requ...@classiccmp.org wrote:
> 
> Burroughs L-series paper tapes

Re: cray unicos cds sold on ebay in 2016

[Michael Thompson via cctalk]

>
> Date: Sat, 11 Jul 2020 15:17:06 -0400 (EDT)
> From: Ethan O'Toole 
> Subject: Re: cray unicos cds sold on ebay in 2016
>
> I have Unicos 10.0.0.1 and 10.0.0.2 but when I boot it I get a kernel
> panic. Seems to be around drivers for ATM. My system has a lot of HIPPI
> interfaces, no ATM.
>
> Am also interested in finding other copies of J90 Unicos.
>
> - Ethan
>

The RICM has 8.0.2.2A and 8.0.3.3 on DAT.

-- 
Michael Thompson

Re: Early Nubus history

[Michael Thompson via cctalk]

>
> Date: Sat, 23 May 2020 07:07:52 -0700
> From: Al Kossow 
> Subject: Early Nubus history
>
> Did anyone ever do any research into the early history of Nubus, wrt
> Western Digital, TI or Steve Ward/MIT/Numachine?
>

I was a member of the IEEE-1196 committee that wrote the NuBus standard and
IEEE-1101 committee that wrote the mechanical standard for the NuBus. Eike
Waltz and I did a lot of the mechanical standards work.

The members of the IEEE-1196 committee were George White (Chairman) R.
Gordon Cook, Mark Garetz(CompuPro and IEEE-696), Richard Greenblatt(MIT AI
Lab, LMI Founder), Ron Hochsprung(Apple), Richard Kalish, Rikki Kirzner(
Dataquest), Gerry Laws(TI), Rae Mclellan(Bell Labs), Gregory
Papadopoulos(MIT), Dan Schneider, Dave Stewart, Michael Thompson(me), Jim
Truchard(Founder National Instruments), Eike Waltz, *Steve Ward*(MIT), and
Fritz Whittington.

George White went from MIT->Computer Automation->Western
Digital->TI->Corollary->Intel. Corollary's cache technology was licensed by
DEC and many others.

My memories of this committee are a little vague after 40 years, other than
being very impressed with the other members. I will see if I kept any notes
from the meetings.

-- 
Michael Thompson

Re: Wanting some help with a PDP-8/a

[Michael Thompson via cctalk]

>
> From: Bryan Longram 
> Subject: Wanting some help with a PDP-8/a
>
> I acquired a non-functional PDP-8/A several months ago and in that time
> I've replaced all the outwardly damaged parts and have gotten the machine
> to power on with no issues. However the problem I've been having now that I
> can't quite seem to pin down is that every time I power the machine the
> address field is displayed as 0 and the value field is displayed as
> . Attempting to change addresses or the value of the address doesn't
> work as I can enter the value just fine but upon entering the Load Address
> button it defaults back to being all sevens.


I am in the process of repairing three 8/a Programmer's Panels. Two panels
had bad ribbon cables. A good panel exhibited the same behavior as yours
when used with the bad cables. I was able to cut the keying peg off two IDE
disk cables to try as replacement cables. They IDE cables don't fit well,
but do work. I will make new replacement cables for all three panels.

-- 
Michael Thompson

Re: DIGI-COMP 1 enhanced (Joerg Hoppe)

[Michael Thompson via cctalk]

>
> From: Joerg Hoppe 
> Subject: DIGI-COMP 1 enhanced
>
> Guys,
>
> I added a motor drive to my DIGI-COMP I, and wrote 4 web pages about
> that device.
>
> See http://www.retrocmp.com/articles/digi-comp-1/
> or just the video https://youtu.be/D6GgxXRJXnw
>
> best regards,
> Joerg
>

That is very cool!
The RICM has a DIGI-COMP, but we have not done much with it other than put
it on display.

-- 
Michael Thompson

Re: Unusual Punched Cards (Peter Van Peborgh)

[Michael Thompson via cctalk]

>
> Guys,
>
> I have been collecting all types of computer punched cards for a few years
> now. In the distant past I actually used them!
>
> I am desperately looking for two types I do not have been able to find a
> sample of:
> *   Jacquard fabric/carpet loom cards. OK, not computer but the
> ancestor, for completeness of the history. There may be several formats of
> these.
>
>
Something like this?
http://www.ricomputermuseum.org/Home/interesting_computer_items/jacquard-loom-cards


-- 
Michael Thompson

Re: RDI BriteLite

[Michael Thompson via cctalk]

> Date: Thu, 5 Mar 2020 14:23:30 +0200
> From: Plamen Mihaylov 
> Subject: RDI BriteLite
>
>  Does anyone have such machine ? I miss the PSU adapter as well as the Sbus
> framebuffer which connects the LCD panel to the mainboard. Any info is
> appreciated.
>
> Best regards,
> Plamen
>

I have several BriteLites, including IPC, IPX, and LX versions.
I will see what power supplies go with them.
The Sbus video board is something special for the LCD panel.

-- 
Michael Thompson

Re: DEC flat cables

[Michael Thompson via cctalk]

>
> Date: Sat, 4 Jan 2020 08:57:40 -0500
> From: David Gesswein 
> Subject: DEC flat cables
>
>Has anyone found a good method for repairing the DEC flat cables?
> The ones with flat wires with plastic laminated to each side. The glue
> holding the plastic on fails and you end up with two sheets of plastic and
> loose wires.
>

For low speed signals. I just replaced the flexprint with modern ribbon
cable. Seems to work just fine.
-- 
Michael Thompson

Re: UniBone: Linux-to-DEC-UNIBUS-bridge, year #1

[Michael Thompson via cctalk]

>
> Date: Thu, 21 Nov 2019 22:13:30 -0500
> From: Chris Zach 
> Subject: Re: UniBone: Linux-to-DEC-UNIBUS-bridge, year #1
>
> One of my long term questions has been to see if a 2020 could talk to a
> RM80. It should be possible as the Massbus personality module talks to
> the bus at 3600 RPM just like the RM03, and they did manage to get the
> R80 to talk to the 11/730 with a dedicated memory channel connection
> (though maybe the R80 was heavily interleaved)
>
> C
>

ITS could boot from an RM80 on a 2020.

-- 
Michael Thompson

Re: PBXes at home

[Michael Thompson via cctalk]

>
> Date: Thu, 19 Sep 2019 22:27:23 -0400 (EDT)
> From: Ethan O'Toole 
> Subject: PBXes at home
>
> A number of years ago I picked up a Lucent Merlin Legend system.
>
>   --
> : Ethan O'Toole
>

I have a little Merlin 410 PBX at home, with the Conference and Music on
Hold plug-in modules.

-- 
Michael Thompson

Re: cctalk Digest, Vol 59, Issue 13 (Curt Vendel)

[Michael Thompson via cctalk]

>
> Date: Wed, 14 Aug 2019 12:06:48 -0400
> From: Curt Vendel 
> To: cctalk@classiccmp.org
> Subject: Re: cctalk Digest, Vol 59, Issue 13
>
> Will...
>
> I?m still waiting for you and the Rhode Island Computer Society to get my
> brand new in the box 9766, the Alignment disk platter, the box of spare
> heads and the other unit 9766 beat up unit up and running that I gave you
> to donate to RICS for free in exchange for you reading the dozen 300mb
> platters I have and then once the data was read they could keep the
> platters...
>
> So still waiting on that...  hint hint hint
>

There are two vintage computer groups in Rhode Island, The Rhode Island
Computer Museum , and the Retro-Computing
Society of Rhode Island . In this case, Curt is
talking about the Retro-Computing Society of Rhode Island.

-- 
Michael Thompson

Re: looking for a 7-track reel tape controller

[Michael Thompson via cctalk]

>
> The same is true for the HP 7970B tape drives, I even have a 9-track 7970B
> that can be switched between 200, 556 and 800 bpi. I only need a 7-track
> head...
>
> Christian
>

The DEC TU20 tape drive is an HP 7975A 200, 556, and 800 BPI transport with
additional electronics to to connect it to the DEC tape drive bus.

-- 
Michael Thompson

Re: looking for a 7-track reel tape controller

[Michael Thompson via cctalk]

The same is true with the TU20.

> On Aug 7, 2019, at 10:06 PM, Paul Anderson  wrote:
> 
> I think you could change heads in a TU10 and add or take out a few boards. 
> I've worked on 7 and 9 track versions in the day.
> 
>> On Wed, Aug 7, 2019 at 6:43 PM Michael Thompson via cctech 
>>  wrote:
>> >
>> > thanks a lot for your hint to the DEC controller. I wasn't aware that the
>> > TM11, TMA11 and TMB11 controllers can handle 9-track as well as 7-track
>> > NRZI-encoded tape drives. However, all these controllers seem to be very
>> > rare in the public out there. Not too surprising considering that DEC TU
>> > and TS tape drives themselves are rare and that 7-track tape drives were
>> > soon replaced by 9-track tape technology in the early days.
>> >
>> > With best regards,
>> > Pierre
>> >
>> 
>> The TC58 Magnetic Tape Controller for the PDP-8 and the TC59 for the PDP-9
>> can be connected to both 7-track and 9-track drives. The TU20 drive on the
>> PDP-9 at the RICM is a 7-track drive. The only difference between the
>> 7-track and 9-track versions of the TU20 is the tape head. All of the tape
>> drive electronics is the same for both versions.
>> 
>> -- 
>> Michael Thompson

Re: looking for a 7-track reel tape controller

[Michael Thompson via cctalk]

>
> thanks a lot for your hint to the DEC controller. I wasn't aware that the
> TM11, TMA11 and TMB11 controllers can handle 9-track as well as 7-track
> NRZI-encoded tape drives. However, all these controllers seem to be very
> rare in the public out there. Not too surprising considering that DEC TU
> and TS tape drives themselves are rare and that 7-track tape drives were
> soon replaced by 9-track tape technology in the early days.
>
> With best regards,
> Pierre
>

The TC58 Magnetic Tape Controller for the PDP-8 and the TC59 for the PDP-9
can be connected to both 7-track and 9-track drives. The TU20 drive on the
PDP-9 at the RICM is a 7-track drive. The only difference between the
7-track and 9-track versions of the TU20 is the tape head. All of the tape
drive electronics is the same for both versions.

-- 
Michael Thompson

Re: looking for a 7-track reel tape controller

[Michael Thompson via cctalk]

>
> thanks a lot for your hint to the DEC controller. I wasn't aware that the
>> TM11, TMA11 and TMB11 controllers can handle 9-track as well as 7-track
>> NRZI-encoded tape drives. However, all these controllers seem to be very
>> rare in the public out there. Not too surprising considering that DEC TU
>> and TS tape drives themselves are rare and that 7-track tape drives were
>> soon replaced by 9-track tape technology in the early days.
>>
>> With best regards,
>> Pierre
>
>
The TC58 Magnetic Tape Controller for the PDP-8 and the TC59 for the PDP-9
can be connected to both 7-track and 9-track drives. The TU20 drive on the
PDP-9 at the RICM is a 7-track drive. The only difference between the
7-track and 9-track versions of the TU20 is the tape head. All of the tape
drive electronics is the same for both versions.

-- 
Michael Thompson

Re: IBM Series/1 (Kevin Bowling)

[Michael Thompson via cctalk]

>
> Date: Fri, 2 Aug 2019 12:40:58 -0700
> From: Kevin Bowling 
> Subject: IBM Series/1
>
> Anyone have one of these?  I'd like to find a system, but images of
> the OS media would be interesting.
>
> Regards,
> Kevin
>

The RICM has lots of Series/1 systems. They haven't been powered on for
decades.
You are welcome to explore what we have.

http://www.ricomputermuseum.org/Home/equipment/ibm-series1
-- 
Michael Thompson

Re: How to format Dectape (TC08 + TU56)

[Michael Thompson via cctalk]

>
> Date: Tue, 28 May 2019 21:21:43 -0700
> From: Marc Howard 
> Subject: How to format Dectape (TC08 + TU56)
>
> Hi,
>
> I fired up the 8/A tonight and the TU56's are failing diags.  I want to
> format a tape for scratch use but I can't find the MAINDEC that does this
> (along with flipping up the backplane switch.
>
> Can someone refresh me on the proceedure?
>
> Thanks,
>
> Marc Howard


MAINDEC-08-EUFB should work on both TC01 and TC08 controllers.

-- 
Michael Thompson

Re: sun model 47. code 4/40 does it have the nvram with battery?

[Michael Thompson via cctalk]

>
> Date: Sun, 2 Dec 2018 16:49:37 -0800
> From: Alan Perry 
> Subject: Re: sun model 47. code 4/40 does it have the nvram with
> battery?
>
> The RDI Britelite (laptop) is a SPARCstation IPX system board in a
> laptop chassis.
>

I have IPC, IPX, and LX versions of the RDI Britelite.

-- 
Michael Thompson

Re: Removing PVA from a CRT

[Michael Thompson via cctalk]

>
> Date: Mon, 19 Nov 2018 10:41:36 -0800
> From: Alan Perry 
> Subject: Removing PVA from a CRT
>
> I recently picked up a Rainbow 100. The PVA between the safety glass and
> the CRT on VR201 that came with it has broken down and failed badly.
>
> I have seen videos and read about removing the safety glass, cleaning out
> the PVA, and reattaching and resealing the safety glass.
>
> All that I have seen basically sticks the safety glass on at its edges and
> leaves a void where the PVA had been. It seems to me that the PVA was
> providing some implosion protection. Would it work to replace the PVA and
> attach the safety glass to the tube with an optically clear adhesive sheet?
> I have seen that this exists, but have never used it before.
>
> alan
>

When we fixed the VR14 at the RICM, we were concerned about the safety
aspects of removing the PVA and just using double-sided tape to hold the
outer glass in place. We bought a thin sheet of Lexan at Home Depot, put
the outer glass on a cookie sheet with the outside surface down, put the
sheet of Lexan on top, and put it in an oven. When the temperature hit 420F
(if I remember correctly) the Lexan softened and conformed to the inside of
the glass. We trimmed the Lexan to size, reassembled the Lexan and glass to
the front of the CRT, and glued the steel mounting band in place. It looks
great, and is probably a lot safer than just leaving the PVA out.

-- 
Michael Thompson

Re: PDP8/a Initial Power Up

[Michael Thompson via cctalk]

>
> Date: Fri, 02 Nov 2018 08:56:08 -0700
> From: Columbia Valley Maker Space 
> Subject: PDP8/a Initial Power Up
>
> Hello everyone - my first post, so be easy on me!
>
> I have just acquired a PDP8/a and a Remex punch tape reader. The unit
> starts up and displays some data on the displays, and that is about all
> I can tell you.
>
> I am going to do some googling about this, but I am looking for basic
> initial tests  something I can enter via the keypad.
>
> I learnt some basic programming in 1978 on a PDP8, but that was the last
> time I touched one, so if you are going to suggest some tests, I need
> complete instructions. I don't know how to modify a memory location, let
> alone enter and check a program. I will pick all this back up very
> quickly and I do use computers in my work a lot - I am also an
> electronic hobby guy and have been for years. My point is I am OK with
> component level measurements, I have a scope and probes, etc.
>
> So there you go - hope to hear back form you guys.
>
> Cheers,
>
> Brian
>
> --
> Brian McIntosh
> Columbia Valley Maker Space Communications Guy
> i...@cvmakerspace.ca
> 250 270 0689
>

Try the toggle-in tests that are here:
https://www.pdp8online.com/pdp8cgi/query_docs/tifftopdf.pl/pdp8docs/toggle_in_programs.pdf

-- 
Michael Thompson

Re: i860: Re: modern stuff

[Michael Thompson via cctalk]

>
> Date: Wed, 31 Oct 2018 14:29:18 -0700
> From: Eric Korpela 
> Subject: Re: i860: Re: modern stuff
>
> A Google search on Skybolt i860 produces interesting results.
> >Additional realtime signal processing
> > capability is provided by four Skybolt i860-based VMEbus single-board
> > computers with 240 MFLOPS peak combined capacity.
> > --
> > Remember when 240 MFLOPS was a lot?
>

That's the board that I have.

Quad i860 on a 9Ux400 VME board.

Its in a Sun 4/280 development system.


-- 
Michael Thompson

Re: PDP, Data General & more (TV show Maniac)

[Michael Thompson via cctalk]

>
> Date: Wed, 31 Oct 2018 19:00:15 -0400
> From: Ethan Dicks 
> Subject: Re: PDP, Data General & more (TV show Maniac)
>
> Looks like a PDP-8/L to me, with a PC04 high-speed paper tape
> punch/reader below it.
>
> -ethan
>

Like this 8/L?
http://www.ricomputermuseum.org/Home/equipment/pdp-8-l

And the 11/05 above it?
http://www.ricomputermuseum.org/Home/equipment/dec-pdp-1105

And the 11/35 above it?
http://www.ricomputermuseum.org/Home/equipment/dec-pdp-11-35

And the 11/04 below it?
http://www.ricomputermuseum.org/Home/equipment/dec-pdp-1103-analogic

And the DG S/130 to the right of it?
http://www.ricomputermuseum.org/Home/equipment/data-general-eclipse-s-130


Michael Thompson

Re: i860: Re: modern stuff

[Michael Thompson via cctalk]

>
> From: Ken Seefried 
> Subject: i860: Re: modern stuff
> >the i860 found at least a little niche on graphics boards, so somehow
> >not a complete failure ;-)
>
>
I have a Quad-i860 VME board in one of my Sun systems.

Michael Thompson

Re: SPACEWAR! Switch Boxes for a PDP-12 (Bob Rosenbloom)

[Michael Thompson via cctalk]

>
> From: Bob Rosenbloom 
> Subject: Re: SPACEWAR! Switch Boxes for a PDP-12
>
> How about these? They look close, but are still a bit expensive.
>
>
> https://www.ebay.com/itm/VINTAGE-SWITCHCRAFT-60312DL-MOMENTARY-SWITCH/253586118419?epid=27018592158=item3b0ae91713:g:NvcAAOSwqMRa4hGS:sc:USPSFirstClass!95051!US!-1
>
> Bob
>

I bought 5x of them. They are the locking style that we don't want, but I
think that we can bend the angled part to make them momentary.

Thanks for the help!
-- 
Michael Thompson

SPACEWAR! Switch Boxes for a PDP-12

[Michael Thompson via cctalk]

Visitors to the RICM like to play SPACEWAR! in the PDP-12. Unfortunately
using the console switches is uncomfortable, not intuitive, and is tough on
the switches. We would like to recreate the switch boxes used on the PDP-1
to make playing a better experience.

We modified the source

from D.E. WREGE

to use the LINC SXL instruction to read the PDP-12 GPIO signals, and
prototyped two switch boxes using recycled toggle switches. This works
great, so now we need to make better switch boxes.

This CHM article shows what we want to recreate.

This article shows a sketch of the switch boxes.

A generous donor made these boxes for us.


The lever switches are turning our to be difficult to find at a reasonable
price. We found some NOS SwitchCraft lever switches that looked like the
sketch and the PDP-1 pictures and were a reasonable price, but our order
was rejected because they only had one in stock. eBay has Mossman and
SwitchCraft, but they are either very expensive (more than $50 each), or
they only have one available.

The switches that we are looking for need to be SPDT, three-position,
non-locking, center off. (If the switches have more than one pole we can
remove the extra poles to keep the operational force low.) Before we cave
in and buy some modern C toggle switches, does anyone have a source for
Mossman or SwitchCraft switches at a reasonable price?

-- 
Michael Thompson

Re: SPARCstation Voyager - Any history?

[Michael Thompson via cctalk]

>
> From: Steve Algernon 
> Subject: SPARCstation Voyager - Any history?
>
> Cleaning up a non-post?ing SPARCStation voyager 146 (are there others?)
> and found a crude cat drawing on the silkscreen:
>
> https://twitter.com/salgernon/status/1029474524100616192?s=21
>
> Just curious if anyone knows any backstory for this kitty. (I was at sunw
> from ?90 to ?92 and this machine is a little after my time!)
>
> ?sma
>

The Sun 386i, Roadrunner, had the roadrunner and the developers names
molded into the case. There are pictures of some of the developers here:
https://sites.google.com/site/mthompsonorg/Home/sun-microsystems/sun-386i-developers

-- 
Michael Thompson

Re: I ran across this strange modernistic? Data General ...odd?

[Michael Thompson via cctalk]

It could be the Intel 8086 version. I need to look at the serial/model number 
tags.

Sent from my iPhone

> On May 23, 2018, at 1:46 AM, Lars Brinkhoff  wrote:
> 
> Michael Thompson wrote:
>> I put a picture of the one at RICM here:
>> http://www.ricomputermuseum.org/Home/equipment/data-general-desktop-generation/DG_Desktop_Generation.jpg
>> 
>> Going from left to right: QIC tape drive, dual floppies, disk drive,
>> card expansion, CPU, and power supply. We have the monitor, keyboard,
>> and printer for it too.
> 
> This is with a microEclipse CPU, right?
> 
> I'm surprised the Nova/Eclipse architecture doesn't get more love.
> It seems quite pleasant.

Re: I ran across this strange modernistic? Data General ...odd?

[Michael Thompson via cctalk]

>
> Date: Mon, 21 May 2018 21:01:59 -0400
> From: Michael Thompson 
> Subject: Re: I ran across this strange modernistic? Data General
> ...odd? computer?
> The RICM has one, but it is not on the WWW site.
>
> Michael Thompson
>
>

I put a picture of the one at RICM here:
http://www.ricomputermuseum.org/Home/equipment/data-general-desktop-generation/DG_Desktop_Generation.jpg

Going from left to right: QIC tape drive, dual floppies, disk drive, card
expansion, CPU, and power supply. We have the monitor, keyboard, and
printer for it too.

Next time I am in the warehouse I will take pictures of the serial/model
number tags of everything.

-- 
Michael Thompson

Re: I ran across this strange modernistic? Data General ...odd? computer?

[Michael Thompson via cctalk]

>
> Date: Sun, 20 May 2018 18:04:00 -0400
> From: Ed Sharpe 
> To: cctalk@classiccmp.org
> Subject: I ran across this strange modernistic? Data General ...odd?
> computer?
>
> While? in the warehouse I ran across this strange modernistic? Data
> General ...odd? computer?
>  I do not remember buying it!? ?Ed#
> ?
> ?
> "https://www.smythretail.com/wp-content/uploads/2012/05/DG10_1-300x227.jpg
> "
>
>
The RICM has one, but it is not on the WWW site.

Michael Thompson

Re: Sparc Laptops

[Michael Thompson via cctalk]

> Date: Fri, 11 May 2018 23:11:57 -0500
> From: "Sam O'nella" 
> Subject: Re: Sparc Laptops
>
> Yes the IBMs are worth tracking down.  I always keep my eye out but rarely
> see them come up for sale but it'd be fun to have an RS/6000 that doesn't
> cause a hernia to move. My only similar one is a tadpole but I don't recall
> the version.  I used a universal power supply to get it to run for a little
> while but then I'm pretty sure the backlight on the lcd popped and went
> out. So I'm also a member of the almost but not quite functioning owners
> club. :-)  Would gladly get rid of some Ultras if I could upgrade to a
> portable.
>

The Tadpole with the 50MHz PowerPC processor was sold as an IBM N40.
I have one of those too.

-- 
Michael Thompson

Re: Sparc Laptops

[Michael Thompson via cctalk]

>
> Date: Wed, 9 May 2018 13:08:51 -0400
> Subject: Re: Sparc Laptops
>
> I have a pretty cool DEC 486 laptop.  I am unsure if they made a Pentium
> laptop before they were bought out.
> http://www.vintagecomputer.net/digital/DECpc_433SLC/
> DECpc_433SLC_Premium_open2.jpg
> b
>
> On Wed, May 9, 2018 at 11:46 AM, Zane Healy via cctalk <
> cctalk@classiccmp.org> wrote:
>
> > I dream of owning an Alphabook.  It?s a silly dream, but it?s one I dream
> > anyway.
> >
> > I have a Sparcbook 3GS (I think that?s the model) somewhere.
> >
> > Zane
>

I have about 15 SPARC based lugables and laptops. Some are TRIgem/RDI
Britelites that have an IPC/IPX/LX motherboard inside, three Voyagers, the
rest are Tadpole SB2, SB3, SB3GX, and Ultrabooks.

  Michael Thompson

Re: Visiting Boston - Classic computer recommendations (Huw Davies)

[Michael Thompson via cctalk]

The KS10 is at my house, along with my DEC, SGI, and Sun collection.

I have a DEUNA and another Unibus Ethernet board, but have not installed them.

At the Lab, we have a PDP-12, and a PDP-8/I that are running. 

Sent from my iPhone

> On Apr 27, 2018, at 1:30 AM, Lars Brinkhoff  wrote:
> 
> Michael Thompson wrote:
>> Please visit us at the Rhode Island Computer Museum. About 60 miles south
>> of boaton.
>> http://www.ricomputermuseum.org/
> 
> If I do, I'd expect ITS to be up and running before I left.
> 
> Do you have anything for KS10 networking?  IMP, Chaos, Ethernet?

Re: Visiting Boston - Classic computer recommendations (Huw Davies)

[Michael Thompson via cctalk]

>
> Date: Thu, 26 Apr 2018 19:17:18 +1000
> From: Huw Davies 
> Subject: Visiting Boston - Classic computer recommendations
>
> I?m in Boston MA (technically Canton) for the next three weeks (April 29
> to May 19). Looking for recommendations on classic computer/classic
> car/sailing things of interest to do on the weekends.
>
> Huw Davies   | e-mail: huw.dav...@kerberos.davies.net.au
> Melbourne| "If soccer was meant to be played in the
> Australia| air, the sky would be painted green"
>
>
Please visit us at the Rhode Island Computer Museum. About 60 miles south
of boaton.
http://www.ricomputermuseum.org/

We will be working in the Learning Lab on Saturdays, and can take you to
the warehouse for a tour of the static storage.

There are classic car museums not far away in Newport and Middletown, and
lots of sail boats in Newport.

-- 
Michael Thompson

Re: PDP8 ALGOL

[Michael Thompson via cctalk]

>
> From: Charles Dickman 
> Subject: PDP8 ALGOL
>
> I have been looking at the available software for the PDP8,
> particularly languages. I see there was an ALGOL. The source is
> archived on Bitsavers and dbit.
>
> There is some information here:
> http://www.softwarepreservation.org/projects/ALGOL/algol60impl/
>
> Has anyone played with this before? Is there any additional
> information on how to use it?
>
> -chuck
>

I have looked at the 4k ALGOL described here:
http://www.bitsavers.org/pdf/dec/decus/pdp8/8-213_4K_ALGOL.pdf

The paper tape images are here:
http://www.bitsavers.org/bits/DEC/pdp8/papertapeImages/set3/

The RICM also has an original set of the DECUS 8-213 ALGOL paper tapes, but
they are different from the ones on Bitsavers. I need to make images of
these tapes.

Students at the UMN are trying to get ALGOL to run on their PDP-12 so they
can run some benchmarking software.

We haven't been able to get DECUS 8-213 ALGOL working. Any help would be
appreciated.

-- 
Michael Thompson

Re: Slightly Meta: Travel tips for people traveling internationally with vintage equipment

[Michael Thompson via cctalk]

>
>
> From: Michael Brutman 
> To: "General Discussion: On-Topic and Off-Topic Posts"
> 
> Subject: Slightly Meta: Travel tips for people traveling
> internationally with vintage equipment?
> Message-ID:
>  mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> I'm actively working on show planning for VCF PNW and I'm noticing that we
> have a few international travelers planning to attend and exhibit their
> machines/projects.  I'd like to put together a FAQ for the logistics of
> traveling with vintage equipment across the US border.  If you have ideas
> please let me know.
>
> For example: Should I plan on providing letters in advance stating that a
> person is a registered exhibitor at our show, including details like the
> show location, dates, times, and contact information in case there is a
> question about why somebody is carrying strange looking equipment into the
> US?  Is there any sort of paperwork or customs form needed even if nothing
> is being sold or left in the US?  Any other gotchas to look for?
>
>
> Thanks,
> Mike
>

I often travel internationally with strange looking electronics. If I am
questioned, I say that it is for my personal use during travel.

If you are bringing things that are very valuable, you can get a Carnet to
temporarily import items to the US and then export them without paying
duty. It is sometimes a painful process to find the right person at the
airport to stamp the Carnet on the way in and out, and often the customs
people have no idea what a Carnet is. The Carnet also costs more than $200
and requires a security deposit based on the value of the item.

https://www.export.gov/article?id=ATA-Carnet
http://www.uscib.org/ata-carnet-faqs-ud-1675/



-- 
Michael Thompson

Joe Rigdon

[Michael Thompson via cctalk]

I see that Joe Rigdon's old WWW pages are still on
http://www.classiccmp.org/hp/joespage.htm, but the email address doesn't
work.

The RICM is interested in the ECRM Omnibus boards that he had.
Anyone have current contact information?

-- 
Michael Thompson

Re: Importing a PDP-8 from Canada

[Michael Thompson via cctalk]

Thanks to everyone who offered advice and recommendations about
re-importing equipment to the US from Canada.
What follows is our experience and does not represent advice or
recommendations from the RICM.

We sent an email to DHS asking about the re-importing procedure and what
paperwork we would need, but never received a reply.

I called the customs office in Highgate Springs, VT where we planned to
re-enter the US. The customs officer said that they were most concerned
about proof of ownership. I asked about not paying any duty because
everything we brought back was of US manufacture. The officer said that
even though it was made in the US if it was purchased in Canada you still
might owe duty when bringing it back to the US.

The RICM has an accession form that all donors sign that deeds the
equipment to the RICM. We added a list of the donated equipment, including
serial numbers, to the accession document. Just in case, we made a
pro-forma (commercial) invoice listing the equipment and an estimated
value. We also found a Form 3311, DECLARATION FOR FREE ENTRY OF RETURNED
AMERICAN PRODUCTS. We filled that out even though it is most likely only
used for getting items back into the US that were sent out for repair.

The customs officer asked if we purchased the equipment, and if it was for
or personal use. Since the equipment was donated we didn't buy it, and
since it was going into the museum's collection it was not for our personal
use. He seemed satisfied and within a few minutes we were on our way home.

The most interesting item that we brought back was an ECRM model 5902
document scanner from 1977 that is powered by a PDP-8/m. It looks like we
have all of the documentation for it, including the software on paper tape.
We will post pictures of it on our WWW page in a day or so.

Thanks again for everyone's help with this project.


> On Mon, Jul 31, 2017 at 8:15 PM, Michael Thompson <
> michael.99.thomp...@gmail.com> wrote:
> >
> > The RICM has an opportunity to get a PDP-8/M (built in Maynard, MA) that
> is in Canada. I remember that there was a discussion on the procedure here,
> but I can't find it with Google.
> >
> > Can you either point me to the discussion, or tell me what the procedure
> is?
>
> --
> Michael Thompson
>

-- 
Michael Thompson

Re: Searching for a Sequent (Ian Finder)

[Michael Thompson via cctalk]

>
> From: Ian Finder 
> Subject: Searching for a Sequent
>
> Reiterating my yearly wanted post for a Sequent Symmetry of any kind. This
> is the first system I ever got root on- I'd love to find one some day.
>
> If you have any leads, please let me know.
>
> Thanks,
>
> - Ian
>
> --
>Ian Finder
>(206) 395-MIPS
>ian.fin...@gmail.com
>

I had to move two Sequent Symmetry 5000s last week so we could assemble
some new pallet racking in the RICM warehouse. I have another RAID for them
in my garage. We only need one for show. What do you have to trade for it?
DEC equipment?

http://www.ricomputermuseum.org/Home/equipment/sequent-5000

--
Michael Thompson

Re: pdp-8/e restoration update.

[Michael Thompson via cctalk]

>
> Date: Fri, 11 Aug 2017 17:22:58 +0100
> From: Rod Smallwood 
> Subject: pdp-8/e restoration update.
>
> Hi List
>
> Well I think I've found why the RX01 is not responding.
>
> The device address (75) is not getting decoded on the controller because
> the CPU does not assert BUS I/O PAUSE L
>
> Which it should do I think when it sees an IO instruction.
>
> Do I have this right?
>
> Rod Smallwood
>

Yes, you have it right. Take a look at E7 pin 6 in the M8330 Timing
Generator. It is in section C2 on the prints. It decodes the instruction
6xxx, USER MODE H, and I/O TIME (1) and drives I/O PAUSE low.

-- 
Michael Thompson

Re: Importing a PDP-8 from Canada

[Michael Thompson via cctalk]

Thanks to everyone for comments and suggestions. It sounds like our normal
accession paperwork would work for a bill of sale and would show the
devices as a donation with no value. Getting the accession paperwork
notarized in Canada might make it look more official.

On Mon, Jul 31, 2017 at 8:15 PM, Michael Thompson <
michael.99.thomp...@gmail.com> wrote:

> The RICM has an opportunity to get a PDP-8/M (built in Maynard, MA) that
> is in Canada. I remember that there was a discussion on the procedure here,
> but I can't find it with Google.
>
> Can you either point me to the discussion, or tell me what the procedure
> is?
>
> --
> Michael Thompson
>



-- 
Michael Thompson

Importing a PDP-8 from Canada

[Michael Thompson via cctalk]

The RICM has an opportunity to get a PDP-8/M (built in Maynard, MA) that is
in Canada. I remember that there was a discussion on the procedure here,
but I can't find it with Google.

Can you either point me to the discussion, or tell me what the procedure is?

-- 
Michael Thompson

Re: tape baking (Rob Jarratt)

[Michael Thompson via cctalk]

>
> Date: Fri, 7 Jul 2017 21:19:03 +0100
> From: "Rob Jarratt" 
> Subject: RE: tape baking
>
> > I long to hear again the sound of the line printer that was attached to
> the
> > DECSYSTEM-20 I used to use. I think it was a drum printer but I don't
> know
> the
> > model (I may have some materials around that mention the model, not sure
> > where they are now though). I could never house one of these though, if
> any
> > still exist.
> >
>
>
> I looked it up, it was a DEC LP20H that they had. I'd love to hear one of
> those running again. Do any still exist?
>
> Regards
>
> Rob
>

A while ago the Living Computers: Museum + Labs borrowed my LP20 controller
so they could clone the boards for one of their PDP-10s. Since they went
through that effort they must have a big line printer.

-- 
Michael Thompson

Motorola SDA7 Dual Transistor

[Michael Thompson via cctalk]

I am trying to LTSpice simulate a DEC H-724 power supply from a PDP-12. It
includes a Motorola SDA7 dual transistor. I can find any information on
this part. Anyone have any info?

-- 
Michael Thompson

RICM Data General Rescue

[Michael Thompson via cctalk]

Dan and I did a rescue run yesterday and came back with four Data General
systems; a Nova/3, a Nova/4, an Eclipse S/20, an Eclipse MV/4000, and a
large assortment of test equipment and spares. All of the systems are in
very nice condition. The Eclipse S/20 is mounted in a cabinet with a model
6125 1/2" tape drive and a fixed disk drive.

In the next week or so I will add them to the RICM WWW page.

-- 
Michael Thompson

Re: Oscilloscope Recommendation

[Michael Thompson via cctalk]

We have lots of dual-trace Hitachi 25MHz analog 'scopes that were donated
by BMI. They are fine for the low speed work that typically do, and don't
have some of the interesting problems that digital 'scopes have. We can get
a deep discount on any of the 'scopes that BMI has:
https://www.bmisurplus.com/products/category/oscilloscopes.

I was looking at some of the mixed-signal 'scopes like the Rigol MSO1104Z.
Having a 'scope and a logic analyzer in the same instrument, with both
'scope and logic analyzer triggering would be very nice.

On Sat, Apr 29, 2017 at 10:07 PM, dwight  wrote:

> If it is your only scope I recommend an analog scope of at least 100 MHz,
> with dual trace and delayed sweep.
>
> If you already have an analog scope, I recommend a logic analyzer instead
> of a digital scope.
>
> If you already have both above, I recommend a digital scope.
>
> Dwight
>
>
> --
> *From:* cctech  on behalf of Michael
> Thompson via cctech 
> *Sent:* Saturday, April 29, 2017 4:15:33 PM
> *To:* allison
> *Cc:* General Discussion: On-Topic Posts
> *Subject:* Re: Oscilloscope Recommendation
>
> Thanks for the recommendation
>
> Sent from my iPhone
>
> > On Apr 29, 2017, at 4:30 PM, allison  wrote:
> >
> >> On 04/29/2017 01:28 PM, Michael Thompson via cctech wrote:
> >> The RICM just received $1,000 to buy a new oscilloscope. I would like a
> >> four channel. and color would also be nice. The bandwidth doesn't need
> to
> >> be high because we usually work on ancient equipment.
> >>
> >> What would you suggest?
> >>
> > I use a RIgol DSO at work to replace a 200mhz Tek with power issues.
> Far better scope.
> > For the money we paid, 4 channels and wide band its very decent.  Being
> able to get
> > screen grabs to a USB stick is a big plus.
> >
> > I personally have a Rigol DS815T spec analyser with tracking generator
> and its a good performer.
> > Not up to the standards of a R FSH6 but about 1/15th the price.
> >
> >
> > Allison
>



-- 
Michael Thompson

Re: Oscilloscope Recommendation

[Michael Thompson via cctalk]

Great idea about looking for a non-profit discount. That might not work for
the Chinese 'scopes, but it could make the US 'scopes prices more
competitive.


On Sat, Apr 29, 2017 at 11:53 PM, Paul Anderson  wrote:

> I've almost always used TEK scopes, and liked them. What ever you choose,
> see if they will cut you a good deal for being a educational or non-profit.
> A lot of companies will, especially on a discontinued model.
>
> On Sat, Apr 29, 2017 at 6:15 PM, Michael Thompson via cctech <
> cct...@classiccmp.org> wrote:
>
>> Thanks for the recommendation
>>
>> Sent from my iPhone
>>
>> > On Apr 29, 2017, at 4:30 PM, allison  wrote:
>> >
>> >> On 04/29/2017 01:28 PM, Michael Thompson via cctech wrote:
>> >> The RICM just received $1,000 to buy a new oscilloscope. I would like a
>> >> four channel. and color would also be nice. The bandwidth doesn't need
>> to
>> >> be high because we usually work on ancient equipment.
>> >>
>> >> What would you suggest?
>> >>
>> > I use a RIgol DSO at work to replace a 200mhz Tek with power issues.
>> Far better scope.
>> > For the money we paid, 4 channels and wide band its very decent.  Being
>> able to get
>> > screen grabs to a USB stick is a big plus.
>> >
>> > I personally have a Rigol DS815T spec analyser with tracking generator
>> and its a good performer.
>> > Not up to the standards of a R FSH6 but about 1/15th the price.
>> >
>> >
>> > Allison
>>
>
>


-- 
Michael Thompson

Re: Oscilloscope Recommendation

[Michael Thompson via cctalk]

Thanks for the recommendation 

Sent from my iPhone

> On Apr 29, 2017, at 4:30 PM, allison  wrote:
> 
>> On 04/29/2017 01:28 PM, Michael Thompson via cctech wrote:
>> The RICM just received $1,000 to buy a new oscilloscope. I would like a
>> four channel. and color would also be nice. The bandwidth doesn't need to
>> be high because we usually work on ancient equipment.
>> 
>> What would you suggest?
>> 
> I use a RIgol DSO at work to replace a 200mhz Tek with power issues.  Far 
> better scope.
> For the money we paid, 4 channels and wide band its very decent.  Being able 
> to get 
> screen grabs to a USB stick is a big plus.
> 
> I personally have a Rigol DS815T spec analyser with tracking generator and 
> its a good performer.
> Not up to the standards of a R FSH6 but about 1/15th the price.
> 
> 
> Allison

Oscilloscope Recommendation

[Michael Thompson via cctalk]

The RICM just received $1,000 to buy a new oscilloscope. I would like a
four channel. and color would also be nice. The bandwidth doesn't need to
be high because we usually work on ancient equipment.

What would you suggest?

-- 
Michael Thompson

Re: LINCtape/DECtape Head Alignment

[Michael Thompson via cctalk]

>
> Date: Sat, 18 Mar 2017 21:46:21 -0500
> From: Jay Jaeger 
> Subject: Re: LINCtape/DECtape Head Alignment
>
> Curious:  How are you measuring the signal from the head?  Do you have
> an honest to gosh differential probe, or are you using some other
> technique?  (If you have a differential probe, then the TU56 manual
> indicates that you should see 10mv-12mv (the addition of the two paired
> heads together), so as a first guess I am guessing you are looking at
> the coils one at a time.
>
> The reason I ask is that the TU56 that I use most often has gotten a bit
> cranky over the years.  Generally I can read and write, but I do
> typically see some errors - unacceptably many, and it *seems* that the
> longer the machine is on, it seems the more mark track errors I get when
> running the ZTCC?? diagnostic (test 3).
>
> I don't have a differential probe, and the A-B math function on my Rigol
> DS2072 scope is not anywhere near fast enough (though maybe a firmware
> patch which I have downloaded will help, but I doubt it will help
> because their is a lot of HF noise on the signals when measuring
> voltages this low).  However, if I apply a 50KHz low pass filter on the
> signal on the scope, then sometimes I can see a 5mv per coil signal
> using an ordinary probe.  I say sometimes because the scope seems to
> have some firmware problems so it isn't consistent in its behavior.  (I
> have downloaded a firmware update that *might* help).
>
> I don't really doubt my heads at this point - certainly nothing is open
> - I can measure each coil at about 1.5 ohms (3.0 ohms across both), but
> it is something I would like to make sure I know how to do.
>
> Also, have you degaussed your heads?  If so, how?  I ask because some of
> my symptoms could point that way (I have yet, for example, to test with
> a tape, have it get worse, then go back with the machine "cold" and see
> if it gets better - and if it doesn't, that could point to demagnetized
> heads.)
>
> Thanks.
>
> JRJ
>

We used the procedure in the TU56 maintenance manual, and used two G888
modules to make the equivalent of the G500 described in the manual. The
G888 modules really cleanup the high frequency noise mixed with the head
signals.

-- 
Michael Thompson