On 22 May 2011 at 16:38, Eric Smith wrote: The 465 (A/B) is a great reliable scope. But if you're used to using DSO's, it can take some time getting used to, particularly on low rep- rate traces. And storage-tube scopes (such as the 5441) require quite a bit of getting used to also. I've seen some early used DSOs on eBay (usually without probes), for under $200, but I don't know how well they work. --Chuck

John Robertson wrote: OK, the device was made by B&K and is a model 2501 Digital Storage Adapter. Two channels, from 20us up to 40 sec. time/div, and from 5mv to 5V/div amplitude. I've got a Tek 465 and have only used the 2501 once, but then I'm not fixing old computers usually, rather we service microprocessor controlled arcade games... John :-#)# -- John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames) www.flippers.com "Old pinballers never die, they just flip out"

On Sun, 22 May 2011, Keith Monahan wrote: I'm a satisfied owner of a "hacked" Rigol 50Mhz. DSO. Very nice gadget! I purchased mine from tequipment.com. --

Choices, choices...I would be straight on ebay. I dont recommend analog storage, they tentd to be difficult to keep working. Some of the old Tektronix just work, although the power supply capacitors may fail as in any device. Tektronix 7000 Y amp switches can be delicate when old and the mainframe socket for the plug-in. Telequipment used to be plentiful and cheap. Some of the Advance (Gould) can be cheap and cheerful. Do you want collectors age scope too. to go with the age of the computer, old Tek 500 series. For computer repair I would also want a logic analyser, you can get a combination scope/logic analyser these days although the idea is not new HP1630 logic analyser series started the trend and dont cost too much second hand. If you wish to verge on the older scope I may have manuals to suit http://www.collection.archivist.info/searchv13.php?searchstr=oscilloscope Dave Caroline

You will not do better than a Tektronix 465. That's the one a lot of DEC kit was developed on and serviced with. Regards ? Rod Smallwood (Digital Equipment Corporation 1975-1985) ? -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Rob Jarratt Sent: 23 May 2011 07:16 To: 'General Discussion: On-Topic and Off-Topic Posts' Subject: RE: Oscilloscope Recommendation In my original posting I said I wanted to use it to fix a PSU. Do you need to know more details? If so, what do you need to know? A couple of people have mentioned analog vs digital. I don't have strong feelings either way. When I was a student I used analog, I have never used a digital one, so I would be happy with whichever is going to be effective and not too expensive. as this is only for occasional use prefer computer Thanks Rob =

On 23 May 2011 at 6:19, dwight elvey wrote: As a 465 owner as well, I agree that it's one of the classic scopes. I'll add that if you do get one, get the manual as well. Tek scope manuals are wonderful and worth their weight in widgets. However, there are places where a DSO is far more valuable. As an example, suppose you need to look at a 20 microsecond string of pulses that are triggered every 300 milliseconds. It'll be close to impossible to see them with a regular analog scope, but a DSO will show them nicely. --Chuck

On 5/23/11 1:09 PM, Rob Jarratt wrote: Keep in mind that a DSO is substantially a different instrument, not simply a "more modern replacement for an analog oscilloscope". Many people, some of whom really should know better, assume this because that's the way things have generally worked with technology, with digital stuff being perceived as "new" and anything analog perceived as "old" or otherwise passe'. This is not completely so with DSOs. They have significant limitations that one MUST be aware of in order to use them effectively. If you don't know what you're doing with a DSO, it will give you incorrect information. That said, I strongly feel that any real electronics bench is incomplete without BOTH an analog oscilloscope and a DSO. -Dave -- Dave McGuire Port Charlotte, FL

On 5/23/11 3:16 PM, John Honniball wrote: Hey, that sounds like a neat scope! I will keep an eye open for one. I've been really impressed with the Philips test equipment that I've seen. My lab counter/timer is a Philips; it's wonderful. -Dave -- Dave McGuire Port Charlotte, FL

On 5/23/11 3:40 PM, Eric Smith wrote: Display update rates and vertical bandwidth limitations can be issues for high-speed stuff like laser hacking. Lack of vertical resolution (8 bits in many scopes) limits display of waveform detail. The "fade out" effects of CRT phosphor in a fast analog recurrent sweep is useful for some applications and tough to emulate, though Tek's "DPO" (Digital Phosphor Oscilloscope) line did make a good stab at addressing that. Ruggedness in extremely electrically unfriendly environments can also be an issue. My friend Jon Singer (noted laser guy) regularly sees trace curlicues, no joke, on his Tek 7104's display during test firings of his lasers...I'm not at all confident of modern digital scopes' ability to survive that sort of electrical pounding. Some of these things are now being addressed by very high-end digital scopes. So nowadays, you might be able to buy a digitizing scope for about the price of a Porsche 911 that might approach the performance in some of the above-mentioned areas of an analog scope that can be picked up for a few hundred bucks, along with a spare. ;) In that situation, it's pretty foolish to push for a digitizing oscilloscope just for the sake of "going digital". Note well that I'm not poo-pooing digitizing oscilloscopes. I have several (Tek TDS3012, HP 54111D, a few LeCroy high-resolution scopes) and I use them regularly. My intention here is to point out that they are not always viable replacements for analog oscilloscopes...they're fundamentally different pieces of test equipment, with different strengths, weaknesses, and applications. -Dave -- Dave McGuire Port Charlotte, FL

On 23 May 2011 at 18:09, Rob Jarratt wrote: Printers, disk drives, data acquisiton. Logic analyzers are useful beasts, but they don't tell you anything about the *quality* of the signal (e.g. ringing, edges, etc.), although some have "glitch" detection. But we don't live in an exclusively analog world. Before DSOs we had analog storage-tube scopes. --Chuck

On 5/23/2011 12:38 PM, Chuck Guzis wrote: Chuck, While not necessarily applicable to the OP, I've found my DSO and logic analyzers to be WAAAYY more useful for 90% of the electronic projects that I work on. I don't do much analog work, and as a result, don't end up breaking out my analog scope hardly at all. There are SOME things that would be better with an analog scope, I guess I just haven't had much a need for it. Keith

On 5/23/2011 1:30 PM, Dave McGuire wrote: I may have said that, but now that you mention it, this isn't at all what I wanted to say. :) Simply put, I find the storage capabilities of a DSO and the capabilities of a logic analyzer to be more useful to the type of tasks that I find myself working on. Luckily, I haven't found any problems with signal quality or integrity, in the digital circuits that I find myself creating/using. I normally play it safe, don't use unreasonably fast speeds, long cables, do RF designs, or create my own circuit boards (yet). I am often using evaluation boards which have eliminated most of the real bad design decisions that I could make. Or I'm probing circuits that have been designed, tested, and so on --- where I've been able to rely on the fact that the signal at the pin should be within tolerances.(if the device is working as it should be) While I'm by no means an expert in any of this stuff, when I work on non-repeating signals, it's my limited understanding that an analog scope does me little good --especially if it's a temporary condition, and only happens intermittently. I'd much rather have some capability to trigger and store the problem, so I can study it. My understanding with the new Agilent DSO scopes I mentioned, is that they have an update rate of 50,000 waveforms per second, which means that you can now view glitches occurring in real time which would be missed by other devices with much lower refresh rates. Keith

I have one of each. Unfortunately my 1741A has developed a horizontal deflection problem, but the 1740 works just fine (except for a dirty switch I need to clean). For the sort of stuff we do, a 100MHz delayed-trigger dual trace scope is pretty much the bomb. The 174x scopes are IMHO a great example of the genre. Of course, just for vintage warm fuzzies, little can challenge an old Tektronix scope. I recently acquired a Tek 561A from a friend locally. Mmmm, vacuum tubes.... Turn on the scope, go get a beer while it warms up, measure and test with confidence. -- Ian

Hi I thought I should note that I've used high speed sampling scopes several times but that was mostly with a 1GHz+ CPU and an expensive low loading FET probe. I've only used a logic analyzer twice in 30+ years of fixing all kinds of electronics. I find them time consuming and not much good for general debugging. In order to use one right, you need to have a rough idea as to what is wrong. By that time, I have been able to narrow it down, that far, I can quickly trace it with a normal scope. Not saying there were not times I needed a logic analyzer, it just that when I did use it, I knew what I was up against. Both times, it was related to tracing down a design bug and not just a bad part. I do beleive that if you are going to get an analog scope, there is no reason not to get a 100MHz one. They are not that much more expensive than a 50 or 20MHz one and there is no penalty in using one. I also recommend one with a delayed trace. As you get better you'll find it quite useful. I should also admit that I do use a DSO for analog work. I have an old Nicolet with a maximum sample rate of 2MHz. I use it because it has a 12 bit A/D and dual chanel. I use it for two reasons. Just right for my analog computer setups. One is that is has infinite persistance if I want and I can digitally increase the gain by 64X and watch for small amounts of drift when setting up intergrators. Something that would be difficult to do with either an analog scope or a regular 8 bit sample. Dwight

In article <4DDC989E.70703 at brouhaha.com>, Eric Smith <eric at brouhaha.com> writes: However, I'd think that exploring a well documented design with a logic analyzer would be fairly productive. Its one thing to look at schematics and "theory of operation" paragraphs; its another thing to look at the signals evolve over time. Particularly when the hardware is spread out over many schematics with connecting signal identifiers between sheets. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com>

I suspect this is going to come down to personal choice, tempered slightly by the sort of machines you're working on. If you ask a dozen hackers (in the true sense) to do soemthing, you'll get it done a dozen ways, using different tools. And all are equally good... I use a logic analyser a lot. Either a handheld one (which I use just about all the time), or an old Gould. Yes, I probably could dfo the same work with a DSO, but the LA is what I am used to. I think, for exmaple, tracing the microcode in a PERQ, PDP11 or HP9800 would be difficult with most DSOs (you need at least 8 or 12 channels), I do it all the time with the LA. For that matter, just hte other day I needed to trace the operation of a state machien with a 5 bit stat register, and various inputs and outputs. Withot an instruemtn with at least 8 input channels that would have been very difficult. It's certainly not the first instruemtn I reach for, but I find most of the itme a multimeter and a logic probe (or even better the handheld LA) will let me find the area that's malfunctioning and give me some clues as to what's wrong. And then I grab the LA... -tony

So do I, which is one reason I prefer a CPU + external program memory to having everything on one chip with no bus access... -tony

On 5/24/11 11:45 PM, Brent Hilpert wrote: Oh, I don't know what it's called, but I LOVE that phosphor! 500-series scopes are just amazing devices in so many ways. If you have the opportunity I strongly encourage you to bring them back to life. They pull a lot of power and generate a lot of heat, but properly maintained they'll behave just fine. -Dave -- Dave McGuire Port Charlotte, FL

On 5/25/11 2:45 AM, Brent Hilpert wrote: :-) My first oscilloscope was a Tektronix 543, followed by an Eico 460. Even though I didn't understand much about electronics at the time (the scopes helped that a lot) getting that Eico unit very quickly gave me an appreciation for Tektronix. (I do have a soft spot for Eico stuff though, but for other reasons.) Look around a bit more. The collectors' market for those scopes is very active, and some of them go for serious money if they haven't been stripped for tubes. The big obstacle those guys face is the shipping expenses...they cost a fortune to ship. -Dave -- Dave McGuire Port Charlotte, FL

In article <c032d669cd07ffc090e37b8e156f6979 at cs.ubc.ca>, Brent Hilpert <hilpert at cs.ubc.ca> writes: The one at the CHM was a gift from Aaron Insinga and was the one donated to the University of Delaware. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com>

In article <4DDD2B86.40108 at jwsss.com>, jim s <jws at jwsss.com> writes: Wouldn't it be better to emulate the disk at this point? Or are you saying you need the *contents* of the disk in order to make it funciton? -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com>

I would expect that the disk drive also has at least one pre-recorded timing track that provided some clocking signal(s) for the machine. It was very common in the bit serial disk/drum-based main memory computers to use one or more tracks with pre-recorded timing information on them to generate some or all of the clocking for the rest of the logic. This was a convenient source for clock pulses that were synchronized with the various other data recorded on the disk/drum, and also helped correct for the small rotational speed variations of the motor that spins the disk/drum, since the clock pulses governing the operation of the machine skewed along with the data. As such, there probably is some "content" on the disk that is required to get the machine running, in the form of clock pulses. Of course, if the characteristics of the clock signal(s) are known, it's not a complex matter to reproduce them with external logic. The high school I went to had a computer in the computer lab made by 3M (the same people that make Scotch Tape and tons of other stuff). It was a process control machine that was donated to the school by Natural Gas utility that used it to monitor and manage gas pipelines. It was a 24-bit, bit-serial architecture, with two main registers (A and B), and main memory was a magnetic drum that held 8K words. Opcode was 5 bits, and each instruction had both an operand and next instruction address. Disk was organized as block/track/sector, so addresses were formed this way. The drum provided a master clock signal that was used by the rest of the machine for timing. The motor that drove the drum was an inexpensive motor much like that that drives a sewing machine. There was some phase-lock circuitry on the clock signal to let the machine know when the drum was up to speed, which would then make the machine go "ready", but there was no active feedback to control the speed of the motor beyond that. If the clock rate from the drum fell outside a window of tolerance, then the machine would lose ready state, and freeze where it was at. The drum was belt driven and one time the belt broke, and the machine froze. I was able to remove power from the motor, put on a spare belt (looked a lot like a vacuum cleaner belt), re-apply power to the motor, and once the drum came up to speed, the machine resumed what it was doing without a hitch. -Rick

I have some photos of the disk unit from John B. It includes a photo of where the drive goes in the computer as well as the disk. Looks like head / track sort of technology, looking a lot like a drum in functionality. http://jimsoldtoys.blogspot.com/2011/05/minuteman-autonetics-d17-disk-drive… On 5/26/2011 12:32 PM, allison wrote:

On 2011 May 26, at 2:20 PM, leaknoil wrote: Hmmm, going from the pictures, isn't the actual disk and motor armature (the rotating-parts assembly) missing?

On 5/27/11 10:02 AM, Richard wrote: probably is the disk platter is missing

I talked to John, and he has a complete system, plus another that was disassembled preparing to be a still life for the art dept. Now both are safe. The photos I posted were ones he found on the web looking for the info. He has the same proceedings papers that Aron seems to be working with, and / or Al. I am encouraging him to get the documentation inventoried. Is the sense of this thread that there may only be three of these, two that may be complete enough to function? Jim On 5/27/2011 3:02 PM, Richard wrote:

On 5/27/11 4:21 PM, jim s wrote: Aron and I have two different proceedings his is TSL-3-71 second meeting nov 1970 the one i've borrowed from richard muller is mcug-2-73 fifth meeting apr 73 Somewhere I have the contents of all the proceedings. The first meeting had the most interesting technical information so it would be good to know which ones John has.

On Fri, 27 May 2011, William Donzelli wrote: All the more reason to make sure all three work. :D g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. http://www.simpits.org/geneb - The Me-109F/X Project ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://www.scarletdme.org - Get it _today_! Political correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

On 5/28/11 3:19 PM, Tony Duell wrote: *snicker* -- Dave McGuire Port Charlotte, FL

On 5/28/2011 2:46 PM, Christian Gauger-Cosgrove wrote: That is you have your Relay Launch Computer. Ben.

On 28 May 2011 17:52, Fred Cisin <cisin at xenosoft.com> wrote: Well, the major bundled peripherals are the LGM-30A (or LGM-30B) and the W56. The former might be found in a museum somewhere. The latter would probably have to have a work-alike unit built. Which can probably be found in <redacted>. Then again, I highly doubt <redacted> would give you one. Also I'm pretty sure using the D-17B with its original peripherals might irrevocably damage the D-17B. There's also the collateral damage of making a city disappear. But the major issue is losing the D-17B; there are only so many of them left!

It has been interesting to see how much awareness there is of the D17B. So what about the successor: the D37C? Built from TI's first(?) IC logic family: Minuteman Series DTL (SN3xx), and contemporaneous with the AGC. I haven't found as much info about it as there was for the D17B. There's a paper from 1974 discussing what to do with them once they were surplussed, as for the D17B: http://www.stormingmedia.us/44/4427/0442777.html How many, if any, remain? Known whereabouts? And then there is the D37D of the minuteman III. Or did the military belatedly decide it wasn't a good idea to release these, with software or without?

On Sat, May 28, 2011 at 02:52:31PM -0700, Fred Cisin wrote: One or more cans of instant sunshine. The task of the guidance computer and other associated peripherals was to ensure timely and precise delivery to whatever location was deemed to be in urgent need of ... enlightenment. Kind regards, Alex. -- "Opportunity is missed by most people because it is dressed in overalls and looks like work." -- Thomas A. Edison

Actually, I was kinda asking for some details of what kind of missile the "minuteman" was. But the answers so far have been much more entertaining than that!

--- On Sat, 5/28/11, Geoffrey Reed <geoffr at zipcon.net> wrote: The Minuteman was actually solid fueled, which allowed it to be easily stored in its silo in launch-ready status. It is for this reason that it's had such a long lifetime. Eariler ICBMs such as the Atlas and Titan I had to be fueled immediately prior to launch. The Titan II used storable liquid propellants, but they were highly corrosive, which led to problems. The Titan IIs had a reasonably long lifetime, into the 80s, but the others were only briefly. --Bill

A fellow I worked with who was in the Air Force in the early 60's then a hardware designer for Astrodata was babysitting Minutman 1's (I suspect) during the Cuban Missile Crisis, and the son of a friend now is a commander of a crew there now. The unit I have is just the electronics, with no software, so no more related to the mil uses than saying you have to destroy all 386s and so forth because some may be used in other machines. The D17's that are surviving w/o the disks are not useful anymore. Also I suspect that the programming may have been recorded on the disks such that it could not be erased, since thermally programming magnetic media for permanent retention of data is also something I saw with surplus Nike program tapes that were scrapped in the late 60's when I was trying to find recording tape for my tape recorder. In that way the guidance program could not be tampered with, and also would probably be more reliable. Jim On 5/28/2011 10:50 PM, Geoffrey Reed wrote:

On 5/28/11 10:36 PM, "Geoffrey Reed" <geoffr at zipcon.net> wrote: Sigh.. Did some checking and the Minuteman 1A carried a 1.2 megaton warhead.

On 2011 May 27, at 3:02 PM, Richard wrote: They ebay photos are different than the photos jim posted earlier in the thread, look at the surface the units are sitting on. Also, the stamped number on the top of the units is different: http://jimsoldtoys.blogspot.com/2011/05/minuteman-autonetics-d17-disk- drive.html http://cgi.ebay.com/ws/eBayISAPI.dll? ViewItem&_trksid=p4340.l2557&item=220784254926&nma=true&rt=nc&si=lahRCXi IK4mEFgVeuPTXT945NcY%253D If I were looking for a complete unit I wouldn't want to be bidding on it without more info. Too bad, as it would be nice to see stuff come together to complete another system.

On 05/25/2011 12:31 PM, Richard wrote: The machine is serial so you need the disk as it's both program store and it serves as "registers". It would be possible to simulate all that using shift registers of the correct length. Allison

On 5/25/11 1:29 PM, jim s wrote: I have slowly been working on one of the D17 users group proceedings. I also bought the D17 documents from NTIS on fiche that I need to scan Obviously I'm interested in finding more documentation, but I'm not too hopeful. It is a disk. Look at the docs on the Autonetics Recomp-II for hints on how the D17 works.

On 5/25/11 1:47 PM, Al Kossow wrote: looks like some more of the 2nd proceedings are up since the last time I looked http://www.insinga.com/aron/antique/d17b2/ also, one of the NTIS manuals was on line so I've put it up on bitsavers

On 05/25/2011 01:50 AM, Brent Hilpert wrote: Also a few escaped the unis to persons. I used to know someone that had one and helped him power it and try to program it. This was back around '71 and I have no clue where things got to. I do know it was bear to program and the logic was temperature sensitive. Can't se that I understood it then but it helped me learn. Allison

On 5/25/11 1:47 PM, Tony Duell wrote: Nice. ;) I currently have an RM547 and a 555. I lack the power supply umbilical cable for the 555 though. I had a 545A many years ago. Glorious. -Dave -- Dave McGuire Port Charlotte, FL