Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

    Free. Just pay for shipping.

So... is this a BUSTED scenario, or YAGI gone wrong? Or are you trying to mitigate JENGA reaching critical mass by applying a little BAIT THEORY to the TEA thread...? 

mnem

[mnementh]

Plus Floppies are more convenient to carry your files with you and then go to computer, or some body else's in another office, and load your files there. Portability.

Floppies are an electromechanical part that is unreliable.

Transfering one 1.4MiB floppy worth of data over 115200 serial is going to take 102 seconds, if my maths is less broken than usual. In 1 minute 42 seconds, the "convenience" of carrying the file via sneakernet (execute copy command, unmount floppy, get to instrument, retrieve disk, move disk, insert disk, mount disk, copy files out of it) is going to be beaten. For trivial things like a file in the 10s of KiB, serial is so much faster it's silly.

Besides, RS-232 is soo archaic today (except where it isn't; I use serial console at work every week, at least) that it carries its own aura de cool with it.

I don't understand the hate for floppies, what else did you want scopes to use back then ? USB ? There was no USB.
Serial link faster ? That's irrelevant, that implies that by some magic wherever you decide / need to put your scope, somehow there will be a computer right there on the bench next to the scope, and that it will have a serial cable and the S/W to go with it... didn't work like that in real life at my school at least. There were no computers in the class room in physics, so the teacher would grab the scope (only had one, was so expensive), bring it to a particular bench in the class, put stuff on the floppy then grab the floppy back to his office, that might a few meters away, or on another floor or even another building altogether.
You need a portable media, and one that's easily usable by the desktop computers of the day. So it was either3.5" floppy or nothing. Simple.

Hell even if by some magic there WAS a computer with a serial cable available right next to the scope, then what ? You transfer your file to that PC, then what ? How do you transfer that file to your computer in your office so you can create your report / Word document with it ? You get it from the network ? There was no network back then in my school, to speak of. So used floppies to transfer files from one computer to another.  And let's say that OK, there was ONE computer in the class room... class room is very large, scope might requires a 10 or 20 meter serial cable to get to the computer... you don't get  silly fast speeds of R232 at that sort of distance, no you just crawl... quite possibly even much slower than a floppy drive would write the file.
So take the scope to the computer at the other side of the room ? Silly, no practical. Once you have setup your scope / experiment, it stays there until not needed anymore. But writing the file to a floppy and grabbing that and taking it to any place to any computer.. yes, that, is  practical.

I don't see, back then, how you could offer the same practically in any other way. Surely all TE manufacturers thought like me that ",5" floppies were the obvious choice, and surely all the customers that paid extra to tick the " FDD " option though that too.

The main reason is we can't be arsed.

I'm probably one of the last holdouts on every major form of media evolution, and even I haven't deliberately put a floppy drive in a PC for close to 20 years. Close to a decade for optical. I have a couple USB DVD/R drives... might even still have a 1.44 USB floppy drive in one of the gazillion boxes of crap that hasn't seen light of day since I left San Damntonio after mum died... I say might have... but as that would suggest, if I do have such it has not seen light of day in over a decade.

So sure... the floppy is right there on these prehistoric scopes... but that's worthless for most people  (even us weirdos in this thread) who might have one old WinXP laptop lying around you can copy files from it with. By the time you dust it off, find the power brick, wait for it to boot and finally lay hands on a USB that prehistoric machine will recognize, or find a free ethernet port and get it talking over your home network, you could literally have hand-drawn the waveform in PAINT.

Even if you have a machine in daily use that can read the floppy... it's still more assache than it's worth.

mnem
 

[Vince]

Yeah but that's still missing 100% my point, everything I said ?! 

[mnementh]

The point is it's not the 1980s anymore; floppy is no longer "the convenient choice".

There are literally a dozen better ways to do it than floppy, and many of them are still compatible with these old machines. While none of the choices available on these machines are great, floppy is still the worst one possible. And in here, everybody knows about those better ways.

mnem
*puts on best Rain Man voice* "Floppy drives suck... yes, definitely... definitely suck..."

[BU508A]

Convert a 1.44MByte Floppy to 256GByte:

[bd139]

Ok some quick lunch time debuggery today. I have located the 465B failure and for once it's not a tantalum capacitor. Well that's not true, there is one shorted tant but that's not what is killing the 5V rail. It's much much worse!

I eventually chased it around and found out that it only borked the power supply if channel 1 was selected. So I traced that down to the channel switch. And yep, it's a tek ASIC has gone short. But it's not an ASIC! Part is labelled Tektronix 160-0204-00 which is actually a 63S141J fuse programmable 256x4 PROM. Manual confirms this.



Fortunately it's documented!



Now the IC is available for £23 which is a bit much so I am considering what other options I can use here to replace it. The actual original blank PROM is fairly unobtainable and I'd probably fuck it up programming it.

Will mull on it for a few days...

[mansaxel]

Again it's about the relevance of it back in the day, not today...

In something of a break with some of the TEA strains, I don't wish for everything to remain as it was. I've lost lots of time and data to floppies. They always were the bad option. I don't miss them.

And what about that scope ? Still waiting for piccies of the boards, have you looked closely to spot signs of corrosion ?

Heh, no chance to fix that until I get back from vacation. It'll have to wait.

[TERRA Operative]

I find taking .BMP screenshots on my TDS784D scope super simple with the floppy. Stick the disk in, press a button, wait a moment and then stick the floppy into my USB floppy drive and copy the file to my desktop to be poked in Photoshop. And sometimes it even does it without errors!
Easier than setting up cables as the scope doesn't live on the bench, as it's too big for my current setup, and sometimes I use it sitting vertically on the floor in which case I physically can't plug stuff in the back.

For my AWG510, I needed the floppy drive to run Pocket Linux to enable me to upgrade the SSD and HDD to CF cards, but it has Ethernet for comms and sits in my rack, so that will be easier once I get it set up.

Plus, I'm a masochist for old, user unfriendly, unreliably flakey and obsolete tech, so pffttppfffppt.   

[Ice-Tea]

    Free. Just pay for shipping.

So... is this a BUSTED scenario, or YAGI gone wrong? Or are you trying to mitigate JENGA reaching critical mass by applying a little BAIT THEORY to the TEA thread...? 

mnem

I... I don't even undertand half of what you just said but it's pretty simply. I don't have the gear to test these, they don't seem to be worth all that much, I can't be arsed to put them on eBay so I figured one of you lot might want to have them for free 

[m k]

I don't see, back then, how you could offer the same practically in any other way. Surely all TE manufacturers thought like me that ",5" floppies were the obvious choice, and surely all the customers that paid extra to tick the " FDD " option though that too.

If I want something impractical, I would sign up to work for a heritage railway. Today, one hangs a serial-to-TCP dongle, driven by the DTR voltage perhaps, on the scope and are done with it. My TDS520 has serial and parallel option, as well as GPIB. That will be useful. Once I get it to run again.

Again it's about the relevance of it back in the day, not today...
As for practicality well the TDS 520 scope itself could therefore be deemed just as impractical as the floppy, and therefore be replaced as well... I mean who wants to carry around a boat anchor and have it take so much space on the bench, when you can have today a compact and light portable scope ?

And what about that scope ? Still waiting for piccies of the boards, have you looked closely to spot signs of corrosion ?

It's impractical here when you use word floppies and mean crackers.
But anyway, floppies, big and small, were de facto media back then.
Everything after that and before networking were actually more or less fragmented and mainly for backups.
Then when USB-stick came it was too small.
So nowadays an overall situation is pretty good, you can even emulate old hardware quite easily.

BTW,
earlier midnight wasn't me, it was a teaser from daughter, who was also visiting there.
But north from Måns I still am, no matter what.

BTW2,
seems that glue gun(8996681780404) is still available.
Maybe it was a resend from me.
Anyway, can't believe how close to electrocuting our selves we actually are.

[m k]

Ok some quick lunch time debuggery today. I have located the 465B failure and for once it's not a tantalum capacitor. Well that's not true, there is one shorted tant but that's not what is killing the 5V rail. It's much much worse!

I eventually chased it around and found out that it only borked the power supply if channel 1 was selected. So I traced that down to the channel switch. And yep, it's a tek ASIC has gone short. But it's not an ASIC! Part is labelled Tektronix 160-0204-00 which is actually a 63S141J fuse programmable 256x4 PROM. Manual confirms this.



Fortunately it's documented!



Now the IC is available for £23 which is a bit much so I am considering what other options I can use here to replace it. The actual original blank PROM is fairly unobtainable and I'd probably fuck it up programming it.

Will mull on it for a few days...

Can't you use regular 74-series stuff?

[Vince]

The point is it's not the 1980s anymore; floppy is no longer "the convenient choice".

There are literally a dozen better ways to do it than floppy, and many of them are still compatible with these old machines. While none of the choices available on these machines are great, floppy is still the worst one possible. And in here, everybody knows about those better ways.

mnem
*puts on best Rain Man voice* "Floppy drives suck... yes, definitely... definitely suck..."

Yes, I am not stupid, I get that. That was you and Mansaxel's point. But that was not MY original point (it all started from my first remark, remember...), and you were both replying to me as if it was the point to begin with, which it never was. Hence it was completely irrelevant, hence I failed to see the insistence on hammering that point 

It is exactly as if I had said for example "I find Nixie displays cool ! ", and then people vehemently  writing essais on how Nixies are crap and colour graphical LCD touch screens are so much better.
Eh ?! What's the point of replying that ? 

Or say, you saying how cool a Dragon avatar and people saying no it's stupid grow up, Dragons don't exist, read up !    If you find Dragons cool there is no need to justify, what's the point of even discussing the reality of Dragons ?! 

I could go on and on...

Maybe you both misunderstood what I mean when I said I found FDD equiped TE "cool"... I thought it was obvious I meant it in an irrational / vintage interest kind of "cool", like we find our old glowing Tek scopes "cool"... 

That said, in Dragon's style, I would like to stir it a little and have a bit of fun, and say that... sorry, but for me, right now....  a scope with a floppy is what makes most sense to me ! 

I am tired of taking 20 pictures of scope screens hoping one them would be half usable, then go back to my computer desk and download the pics, adjust compression ratio etc.
I don't want to have cables running across the floor on my living room either to go from the bench/scope, to my computer/desk., be it serial or GPIB or Ethernet or anything cable. Don't have these cables anyway. No all I want, sorry, just like in the '90s when these scopes were current is.... shove a freaking floppy inside the scope, put my screen capture on it, grab the floppy and take it to where ever in the house my desk/computer might be, then read that freaking screen capture, and call it a day ! A portable medium, any medium, don't care, but a portable one. USB would more practical, but not by much. file sizes are small so even on a floppy it doesn't take too long too write, I don't care one bit.  OK my computer, even though it's 15 years old, doesn't have a floppy drive ? I can add one, must have one somewhere. Worse case I just get a cheap old used external floppy drive that you plug into a USB port, and that's all, big deal !! 

See ? I can stir it too when I want ! Hey I might morph into a Dragon one day who knows !

[bd139]

Ok some quick lunch time debuggery today. I have located the 465B failure and for once it's not a tantalum capacitor. Well that's not true, there is one shorted tant but that's not what is killing the 5V rail. It's much much worse!

I eventually chased it around and found out that it only borked the power supply if channel 1 was selected. So I traced that down to the channel switch. And yep, it's a tek ASIC has gone short. But it's not an ASIC! Part is labelled Tektronix 160-0204-00 which is actually a 63S141J fuse programmable 256x4 PROM. Manual confirms this.



Fortunately it's documented!



Now the IC is available for £23 which is a bit much so I am considering what other options I can use here to replace it. The actual original blank PROM is fairly unobtainable and I'd probably fuck it up programming it.

Will mull on it for a few days...

Can't you use regular 74-series stuff?

Nope - no matching parts 

[xrunner]

Maybe you both misunderstood what I mean when I said I found FDD equiped TE "cool"... I thought it was obvious I meant it in an irrational / vintage interest kind of "cool", like we find our old glowing Tek scopes "cool"... 

I understood you Vince. 

[bd139]

More 465B shenanigans. So I figured I'd just do a short check on the IC and see if it was pin specific. Well it was.  Only the A3 line pin 4 was short to ground which is the CH1 select line.



Figured the best option here would be to just bend that pin out and see if the rest of the scope works. So here it is giving me the finger:



Of course I pulled the shorted tant out of the HV supply as well just to see if that would come up, but without a suitable fuse I'm not willing to power it the HT up in case I blow out the inverter transformer.



So next step is to find a suitably priced fuse and stick it in and see what else is broken and if it's worth spending £23 on an IC for 

The scope does power up now but without HT. Progress!

[Vince]

Ok some quick lunch time debuggery today. I have located the 465B failure and for once it's not a tantalum capacitor. Well that's not true, there is one shorted tant but that's not what is killing the 5V rail. It's much much worse!

I eventually chased it around and found out that it only borked the power supply if channel 1 was selected. So I traced that down to the channel switch. And yep, it's a tek ASIC has gone short. But it's not an ASIC! Part is labelled Tektronix 160-0204-00 which is actually a 63S141J fuse programmable 256x4 PROM. Manual confirms this.



Fortunately it's documented!



Now the IC is available for £23 which is a bit much so I am considering what other options I can use here to replace it. The actual original blank PROM is fairly unobtainable and I'd probably fuck it up programming it.

Will mull on it for a few days...

Wow this scope is not an easy one it looks like, but it found its master it seems ! 

I guess you could just use any (as old as possible) easier to get, cheap 8 bit PROM or EPROM instead, and just not use the upper 4 data bits that's all.
But that means having to make a little adapter board of course, so more work and expense... bugt more worryingly, given how compact/crammed these portable scopes are... is there sufficient space to fit an adapter board to begin with... you tell us ! 
Maybe instead use a more modern low profile surface mount flash or EEPROM memory, but then it means it will probably have faster rise times and maybe that will cause problems in the scope, not working at all, or introducing noise that might be problematic in the most sensitive attenuator settings ?! 

Regardless, didn't know these scopes used good old lookup-table PROM trick, pretty neat... I find it cool (nice CERDIP package to boot  ), like floppies ! Stirring the shit again ! 

[bd139]

Think I might just buy the replacement. Seems less painful 

Well serendipitous thing happened. I was chucking the case back in the cupboard of doom and I hadn't looked in the pouch on it. Guess what fell out:



Yes a a spare graticule, manual and some fuses. The correct HV fuses!!! So I chucked one in and it comes up and seems to work.



The HT intensity is really jumpy because the feedback network filter capacitor has been removed (the shorted tant) but it's working.

I have capacitors arriving in the next couple of days so I will sub them in and chuck the case on and do a full retest. Once everything is confirmed mostly OK I will buy the replacement IC 

At the moment channel 1 doesn't exist so I can only do limited tests.

[Vince]

Ah cool, it's worth tackling the PROM issue then now, isn't it ! 

[Ice-Tea]

Spark gap.

https://youtube.com/watch?v=tTaRLzKjoHM

https://youtube.com/watch?v=tTaRLzKjoHM

[TERRA Operative]

Ok some quick lunch time debuggery today. I have located the 465B failure and for once it's not a tantalum capacitor. Well that's not true, there is one shorted tant but that's not what is killing the 5V rail. It's much much worse!

I eventually chased it around and found out that it only borked the power supply if channel 1 was selected. So I traced that down to the channel switch. And yep, it's a tek ASIC has gone short. But it's not an ASIC! Part is labelled Tektronix 160-0204-00 which is actually a 63S141J fuse programmable 256x4 PROM. Manual confirms this.



Fortunately it's documented!



Now the IC is available for £23 which is a bit much so I am considering what other options I can use here to replace it. The actual original blank PROM is fairly unobtainable and I'd probably fuck it up programming it.

Will mull on it for a few days...

Can't you use regular 74-series stuff?

Nope - no matching parts 

Ooh, maybe a microcontroller on a little adapter board?

Oh yeah, chip shortage...

Got a spare Arduino Nano clone laying around? 

[TERRA Operative]

Me and Vince will sit over here with our huge TDS scopes and our cool floppy drives because we are the cool kids.

[bd139]

USB sticks is where it's at 

As for a Nano, don't think I could sub one in there. PROM has 30ns turnaround. Even a simple C LUT can't touch that I don't think.

[Vince]

Exactly.

And floppies are still way cheaper and faster and more convenient to move data around, than HAM radios data links or smoke signals. I will have a floppy any day thanks !

[Vince]

USB sticks is where it's at 

As for a Nano, don't think I could sub one in there. PROM has 30ns turnaround. Even a simple C LUT can't touch that I don't think.

Yes why bother programming a micro when you can just program a ROM instead and be done with it, anyway ?!

I guess as an exercise for kids why not, but as a practical and efficient solution not really 

[tggzzz]

Floppies are an electromechanical part that is unreliable.

My Apple Smalltalk floppies from the 1980s still work.

I'm not sure that flash drives won't leak electrons over that time interval. ISTR I've seen statements of "years" rather than "decades", which is enough for me to want to keep multiple copies of backups.

The core concept to keep in mind here is that if you are relying on one single instance of <anything> to safekeep bitstreams regardless of content, you're doing it wrong. Because <anything> will break. At the most inconvenient point in time, at that.

Edited to add: I dislike floppies for their lack of speed and them forcing me to be present to execute the sneakernet transport, and that is in addition to GENERAL ERROR READING A:

(Who the fuck is General Error and why is he reading my drive? )

Just so, but the options were (and are) rather limited for these:



Smalltalk was glacial, partly because it didn't even have L Peter Deutsch's seminal JITter.