TRS-80

[steve001]

wow that post office relay

Believe it or not they are still used in the substation industry - big is good

made a few PCB's with tape and acetate sheet in my time also - yes the transfer sheets with the lines curves and pads withe the plastic spatula thing to rub them down. Again from tandy. i used to etch mine by putting them in the back garden in the sun for several hours.to develop the photo resist
Trying to get a dual side to line up was a whole different ball game its so easy now

i make a wobble board out of wood with a wiper motor to rock the bag of ferric chloride to etch the boards

I wonder what percentage of computer users at the time interfaced their machines to something, to those that either enjoyed programming or just saw them as a way to play a game?

I can remember interfacing from the beeb user port to pin5 on a 555 i didn't get any meaningful notes just a horrible noise that annoyed my step sister at the time

[chipfryer27]

Hi

i didn't get any meaningful notes just a horrible noise that annoyed my step sister at the time

You were in UltraVox weren't you.... Of course to many "this means nothing to me..."

I knew of rumours about sunshine developing but never heard of any success until now. You certainly sound like a very resourceful "kid" and that wobble board... genius....

Regards

[steve001]

You certainly sound like a very resourceful "kid" and that wobble board... genius....

I cannot take all the credit, my dad was a big inspiration

[chipfryer27]

Hi

Back to a few weeks ago courtesy of "CE" (aka Chinese Export).

A colleague has an impressive amount of battery powered tools by a major, well respected brand. Unfortunately at some point he bought a non brand battery. I've no idea of the make, age or anything else and now impossible to tell. It apparently had all the necessary connections for the charger to operate but who knows the quality of anything inside...!

He put it on charge, in branded charger and all was good. Was...... a "kaboom" later and it's raining fiery shrapnel.... Nowhere in the Evil Lab are you more than a couple of metres from a fire extinguisher of appropriate type, so no real possibility of a fire starting and catching hold, but appropriate type for a Lithium battery is powder..... That is messy, but well, well worth it and I urge all to have one at hand.

As mentioned, they are messy so I will be continuing to clean up the mess for the next few days. My TRS-80 was near-ish and now looks like it was the star in a Head & Shoulders advert prior to use..... A multimeter looks like I rescued it from Pompeii.....

Needs a clean since you last saw it....

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As documented, the TRS-80 has open keys, so there is a strong chance that the dust is now inside the keys. I'm hoping the vacuum will pull most out, but it needs to be stripped to be sure. Same with the monitor once I dig it out. Good job I now know which screws go where.


Meter.... I think...

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This did serve as a harsh warning to my colleague, to never buy non brand Lithium from cheap sources. If you have never seen one go kaboom, keep hoping you never do. It is without any wonder that many electric vehicles such as scooters, hoverboards (stupid name) etc are banned on public transport. It's for a reason.

It is worth noting that you can now get an extinguisher tailored for Lithium from Screwfix (UK trade store, other stores will have them too) which has (I think) a suspended vermiculite which encapsulates the battery and cells inside, helping to prevent further thermal runaway and more kabooms.

Regards

[mnfisher]

A warning indeed.

Luckily no one hurt - but quite a mess. Hope it's not done any lasting damage to the TRS-80. Your friend should be on cleaning duty for the rest of the week.

Martin

[steve001]

Hi All

Can i add to this ...

never buy non brand Lithium from cheap sources. If you have never seen one go kaboom

never buy non brand components from cheap sources. At work we see quite a few MOV's and PTC's from "CE" go kaboom on customers PCB's

for those that have never seen a lion battery explosion - please see below

a test on a 6.3 Kwhr Lion Battery pack that is typically installed in a domestic BESS or an Ebike

The video shows the ignition of a vapour cloud explosion from a synthetic mixture of CO, CO2, hydrogen etc representing the vapour cloud released pre-ignition from lithium-ion batteries.

This was one of a series of tests conducted at the DNV site at RAF Spadeadam in the UK
The tests were conducted in a 26 m3 chamber – 80% of volume of 20’ shipping container - with 11 m3 partitioned off with a flimsy plastic sheet glued across the container to form a blast wall.
The video shows a 28.7% mix with air.
The video is awesome for several reasons: it shows the explosion front developing around the spark from the igniting fuse and expanding; it shows just how violent the explosion is from a small LiB (equivalent to a 0.6 - 6.3 kWh battery [500 - 6000 L/kWh]

finally-despite the plastic blast wall the max overpressure was 0.3 atm - more than enough to kill and sufficient to damage masonry buildings.

Detonation of lithium-ion battery vent gas

https://www.youtube.com/watch?v=vnMJu2- ... terysafety

Regards

Steve

[chipfryer27]

Wow.....

[chipfryer27]

Hi

It's taken a few weeks but Evil Lab is now no worse than it was before the kaboom. I spent the whole day after with a vacuum, then a few hours each day thereafter sucking up the dust (and wiping down too). Eventually the Ivory Tower was deemed clean and I moved downstairs to begin again.

Not perfect and I'm sure I'll be finding dust for a long while yet, and I still have the component drawers to do (deep joy) but I'm very happy that my TRS-80 is alive and well and seems to have survived the ordeal unscathed, just needing a bit of a freshen up

I'm impressed with work of Henry HEPA. I might just give him a new bag.......

Regards