EEVblog #561 - Mailbag

[Kjetil]

Huh, throwing away stuff like this is a sin imho, those obsolete stuff does not have real value, but to try it out, learn something, or just hack for fun, it is fantastic. If you do not need it, somebody would be glad to get it, or even pay for it, or at least shipping.

Yes I know it's a sin, but we also had way too many of them. We did keep the best examples. Shipping is expensive here in Norway (sending a small letter to US/AU costs US$6.50 or thereabouts), and packages even more, so we decided it wasn't worth the time. I do love vintage stuff, but not when you inherit a electronics club full of it (from roof to ceiling), with no room to put modern, more interesting gear

[RobB]

There is a reason they are called aluminium cans Dave  and the sample was clearly machined not etched.

[RobB]

I think you should pass it on to Mike. He has access to weird and interesting stuff, so this fits his style and knowledge I think.

+1 Mike is the king of reverse engineering and fundemental physics

[Macbeth]

I think we just threw out heaps of those old bubble-displays while tidying, didn't know they'd be of any interest to anyone 

Nooooooooooo! My first calc (a Texet IIRC) had a bubble display. Indeed, the first Sinclair digital watch used them I think.

Mark my words - they will become the next Nixie or VFD when the hipsters re-discover them 

[Kjetil]

Nooooooooooo! My first calc (a Texet IIRC) had a bubble display. Indeed, the first Sinclair digital watch used them I think.

Mark my words - they will become the next Nixie or VFD when the hipsters re-discover them 

Maybe I should try to dig them up then :-P

[calexanian]

An older gentleman I knew who just recently passed used to make basically 7 segment displays with neons in them, and later they switched to LED's. It was a nice aluminum cube with flat lenses and sectioned off areas inside and backfilled with clear resin. They looked very nice and durable, but when genuine 7 segment displays became affordable they stopped making them.

[Steffen]

Have seen the scene with the power cord. Totally out of spec. even with contact resistance about 1.x Ohms for all three wires it's out of VDE regulations. Device and wiretests for VDE 0701/0702 test the PE path with up to 25A for a standard safetyclass I 3,6 kVA Device and the PE connection has to be below 0,3 Ohms below 5m length. Add 0,1 Ohm per additional 7,5m for specified boundaries (Max. 1 Ohms). Sorry, I don't know the origin of this cord, but the EU has to be more strict about this. Theses power cords can cause real problems like fire or injuries. The EU or the Federal Republic of Germany has to insure that thoes wires can never pass our borders. The saftety logos are fake as usual.

[Len]

robrenz should be the last person to get the LVDC board, so he can restore it to pristine condition.

[VK3DRB]

Very interesting mailbag.

I suspect the PCB may have been made by IBM. It looks similar to some boards that also had DTL in them in that era. IBM created the computer used in Apollo 11, so maybe the one in the mailbag an IBM developed board. That same Apollo 11 computer technology was used in the IBM Series/1, a system I really  enjoyed working on in the early 1980's.

The Series/1 was an incredibly flexible machine employing open ended architecture. The applications were extremely varied - overnight money market communications interface at the major banks, Telecom directory assistance, hotel management, and processing for the oil industry to name a few.

The smelliest application was a big laundry company in Melbourne that washed hospital bed linen. The Series/1 was used to count dirty bedsheets as that were thrown down a shute. I have to literally run holding my breath to get the the machine to work on it, especially in the summer.

The strangest (and second smelliest) application was at the Howard Florey Institute at Melbourne University. The Series/1 was connected up to a number of sheep to measure hypertension via the salt content in their flesh.

[VK3DRB]

The LED with 20mA through it is probably not defective. The early ones from before about 1973 were very inefficient compared to today. Remember back to the late 70's... your standard off the shelf red LED needed 15-20mA to glow decently. I am surprised the bubble LEDs used so little current though. Those LED digital watches using bubble LED's chewed though batteries.

Recently I was experimenting with an ultra high brightness blue LED. I found that even 50uA still made the thing glow dimly! These days, 1mA is usually enough for a debug indicator on a PCB.

[steves]

How about a countdown timer using a Nixie and with the Saturn chips in the control logic?

[wilheldp]

My suggestion for the LVDC board is:

Fran - Originator
Dave - Further deconstruction
Mike - Xray, further deconstruction
Ben Krasnow - SEM, further deconstruction
PhotonicInduction - See how it handles 10kV

[JoannaK]

Hey Dave,

yes, the wire is too thin. But I have a suspicion that it isn't even copper. Did you notice the springy-ness of the leads? And the resistance is way too high as well.

Might be fun to put 16A through it to see what happens....
or at least measure the resistance

220v/16A on a skimpy wire like that... I'd expect to see something more in line with Photoninduction's videos.. Aka smokin and burn carpet.

PS: what's the idea with those floor-sized carpets Brits seem to love? Ain't those hard to keep clean etc?

[99tito99]

Hi Dave,

How about pulling the wires from that One Hung Low plug and send 250V at 16A and see if you get some Chinese smoke.

Cheers,
Science-Mark
**************************

[chickenHeadKnob]

PS: what's the idea with those floor-sized carpets Brits seem to love? Ain't those hard to keep clean etc?

Joanna in the English speaking world we call those "floor sized" carpets wall-to-wall carpets. Yes they are very popular, and yes they are very filthy. You started to see them become very common in North America in the mid 1960's. It was a way for poor and low middle class people to feel they were living the luxous, and for builders of cheap commodity tract housing to equip the new housing supply with the tacky look their tasteless moron customers demanded. Every house in Canada built    in the seventies came with shag carpet in the living room, and sometimes in all the other rooms except the kitchen. Think about shag bathrooms with men and boys pissing and dribbling all over! 

They are not only hard to clean they are impossible to keep clean. Oh sure there are an endless number of fly by night carpet cleaning companies which will hound and pester you with unsolicited advertising and the do it your-selfer can rent steam cleaners at any home-depot type place, but these cleaners are just a fiction. Once you steam clean, and you need to do it over and over, you get to the point were the rinse water sucked out of the carpet is a pale brown. That is as good as it gets, the remainder of the dirt is permanently bonded in the fibers and now you have a layer of detergent residue which means new dirt clings that much better/faster than before.

Once your dog does this: http://youtu.be/gFvkr6GBWLw on your new carpet, its all over for that one.

[warp_foo]

My suggestion for the LVDC board is:

Fran - Originator
Dave - Further deconstruction
Mike - Xray, further deconstruction
Ben Krasnow - SEM, further deconstruction
PhotonicInduction - See how it handles 10kV

I'd vote for this!

[RupertGo]

The story of Monsanto and LEDs is fascinating. The company was the first to mass-produce LEDs, mostly because it was really interested in selling phosphorous-compound materials (still is, as phosphates) and wanted to grow the market. It got into bed with HP, as test equipment was the obvious market for data displays back then, but it didn't really work out.

Here's a good take http://datamath.org/Display/Monsanto.htm on the story, including stuff on Nick Holonyak, father of the LED and much more besides.

Monsanto got out of LEDs in 1979; it just didn't fit with its business and competition by then was fierce.

[steves]

My suggestion for the LVDC board is:

Fran - Originator
Dave - Further deconstruction
Mike - Xray, further deconstruction
Ben Krasnow - SEM, further deconstruction
PhotonicInduction - See how it handles 10kV

I'd vote for this!

Yeah, and then Jeri could make replacements for the popped ones.

[Kjetil]

My suggestion for the LVDC board is:

Fran - Originator
Dave - Further deconstruction
Mike - Xray, further deconstruction
Ben Krasnow - SEM, further deconstruction
PhotonicInduction - See how it handles 10kV

You should have Laina in there too, to talk about all the brilliant people who have worked on this 

[VK3DRB]

Hey Dave,

yes, the wire is too thin. But I have a suspicion that it isn't even copper. Did you notice the springy-ness of the leads? And the resistance is way too high as well.

Might be fun to put 16A through it to see what happens....
or at least measure the resistance

A friend once bought an el-cheapo soldering/desoldering station on eBay from Hoo Flung Dung.

It appears Dave's cable was made of the same crap (excuse the pun) as that in my friend's soldering station. My friend had cut the mains plug to put an Aussie mains 3-pin plug on the end. It was not copper wire but some cheap alloy that you could not solder to. Very flimsy. I replaced the cable... and had to overhaul the machine. It was full of dry joints and the mains active wire inside almost touched the frame, which had a dodgy earth terminal!!!!

No compliance labelling.
No quality control.
No common sense.
No brains.

Who checks these goods coming in?

The Australian government has lost control in stopping such dangerous and shoddy goods coming here from third world countries like communist China via eBay. I dare say other developed countries might have the same problem with the importation of this type of crap from eBay.




 

[tusisma]

I just found the maintenance manual for the LVDC boards:

Part 1:
http://www.ibiblio.org/apollo/Documents/LaboratoryMaintenanceInstructionsForLVDC-Volume1-GeneralDescriptionAndTheory.pdf

http://www.ibiblio.org/apollo/Documents/LaboratoryMaintenanceInstructionsForLVDC-Volume2-MaintenanceData.pdf

More docs for the Saturn Project.
http://www.ibiblio.org/apollo/Documents/

[VK3DRB]

For a run down memory lane, have a look at this Burroughs promo for logic modules.



look at the logic modules around 1.36 minutes - a valve based logic one then a plug in transistor logic module then ICs. And the "huge" disk storage.

Brilliant. Thanks for the post! In those days every man wore a suit and a tie in the computing industry in Australia. Today, suits and ties have been replaced by largely casual dress codes... a sign of the times I guess.

The video reminded me a triode-pentode valve with resistors and capacitors integrated into the glass envelope that I have around here somewhere. It was used (if I recall correctly) in an either an old IBM 557 Alphabetic Interpreting Machine or maybe an 082 card sorter as one bit memory.

I would argue integrating the passives into the valve was the world's first integrated circuit, probably invented by IBM (it was an IBM brand valve), without any silicon except that in the glass.

If find it, I'll post it to Dave Jones for his mailbag.

[mikeselectricstuff]

Passives inside glass valve envelopes date back to the 1920s
http://electricstuff.co.uk/loewe.html

Later, there were also all-glass memory and A-D converters
http://electricstuff.co.uk/glassadc.html

[Kjetil]

Huh, throwing away stuff like this is a sin imho, those obsolete stuff does not have real value, but to try it out, learn something, or just hack for fun, it is fantastic. If you do not need it, somebody would be glad to get it, or even pay for it, or at least shipping.

I managed to save two of them from the trashbin, two Itron fg410e2 Vacuum fluorescent tubes, originally specced in 1978. I haven't been able to test if they work yet.

[VK3DRB]

I just found the maintenance manual for the LVDC boards:

Part 1:
http://www.ibiblio.org/apollo/Documents/LaboratoryMaintenanceInstructionsForLVDC-Volume1-GeneralDescriptionAndTheory.pdf

http://www.ibiblio.org/apollo/Documents/LaboratoryMaintenanceInstructionsForLVDC-Volume2-MaintenanceData.pdf

More docs for the Saturn Project.
http://www.ibiblio.org/apollo/Documents/

THANKS!!!!!! What a find. I was right... it was an IBM card. They never used industry standard numbers on their chips until they produced the  PC came along.

As you can see, it was very well documented. The technical description is excellent.

IBM documented their mainframes really well. They never used standard logic symbols. Everything was a block and the libraries of technical manuals were huge.