Test Equipment Anonymous (TEA) group therapy thread

[Vince]

I received my vintage chip programmer the other day ! Last night I gave it a good clean and proceeded with a tear down of course, and played with it.

Too much to post on here, so I just spent 2 hours writing a dedicated thread for it :

https://www.eevblog.com/forum/repair/vintage-chip-programmer-micropross-rom-3000u/msg4494400/#msg4494400


In short : badly packed, damaged in shipping. Some cosmetic issues/battle scars, but otherwise great condition inside out. Not a speck of dust inside, it's immaculate in there.
It powers up, the line filter is not a Schaffner so it did not explode.
Power supply looks like an off the shelf module, all rails appear to be working and in good health/low ripple..  We have +/- 5V and +/- 12V.

The heart of the system is a stack of 5 boards + a back plane board.
It's got a CPU board with a 6502 chip and a 16KB EPROM.
A board for the floppy drive controller, and 3 boards to handle  the I/O for the programming fixture (ZIF 40 pin).
Looks like it can generate x5 different programming voltages.

It basically appears to be alive : at power up, PowerON LED on the front lights up, and the CPU is trying to boot from the floppy drive, for a minute. So the brain of the instrument clearly is alive.

As for a local user interface for a stand alone operation, forget it : that black rectangle on top of the instrument, which I thought with some luck was a smoked piece of perspex with LED displays underneath maybe.... nope. It's just a piece of ESD foam to let you put your delicate EPROM chips !

So despite the floppy drive and extensive local smarts of this device..... hence plenty capable of being standalone.... is definitely only meant for remote operation, connected to a desktop computer via the DB25 ports at the back, which are the only I/O for this thing.

[McBryce]

Don't forget to make a copy of the internal EPROM contents just in case the EPROM fails at some time in the future.

McBryce.

[TERRA Operative]

Good thing he has just the device for that!.... wait....

[McBryce]

Good thing he has just the device for that!.... wait....

Just like any other TE, one is never enough!

McBryce.

[Vince]

Yes it's a chicken and egg situation here ! 

I will buy that TL866 or something that everyone buys one, one day, but IIRC at 80+ Euros minimum it's still a pretty penny for me right now.

So... this gave me an idea !

Short term, why not try to make my own EPROM reader ? Just a simple reader, just for the most common old EPROM.

30 years ago when I was a boy and starting in the hobby, I remember the hype in the hobby electronics magazine was all about making all sorts of weird and wonderful gadgets that you could connect to your desktop computers // port ! All sorts of things... relay board, I/Os, MCU programmers, and EPROM programmers I am pretty sure !
You could even buy entire books solely dedicated to // port DIY projects !  Like  " 101 // port projects " or something. The electronics shop down town here is very old fashioned and the old guy running it since 1989 when he created the business, still has shelves full of these old '90s books, I am pretty sure he must have one such book !
The articles would give you the source code for a simple program in MS-DOS BASIC that you could type yourself, to get the gizmo going.
I remember they would use the control lines, unused, to draw some current via diodes to power the gizmo.

Back then, we had no computer at home so I could only dream of these projects. But now.... I have a vintage computer sitting here waiting just for that kind of projects ! Time to get my revenge, 30 years later !
We have a saying in French, I think it translates in English as well " Revenge is a meal best served cold ", or something like that...

Yeah, let's do my first  // port gizmo !  I have plenty of old printer cables I could use, cut the Centronics connector to get at the wires and solder that to a proto board.

What do I need ?

- Proto board... cheap enough, can get some.

- IC sockets...have plenty of.

- some TTL or CMOS logic chips, shift registers to write the address bus and read the data bus.
No shortage of TTL or HCT chips here.

Software ? NO CLUE ! 
Will have to get and install a copy of Basic for MSDOS, and read up on how to use the // port and writing a HEX file on disk.
I can just look online for old projects...

15 years ago I bought  DVD with all the archives / projects from the Elektor magazine, from their beginning I think. There has to be some such project in there somewhere...


Oh yeah that's fun, one more little project to play with ! 

OK maybe the Chinese sell a ready made one for 3 bucks delivered, but that's not as much fun as designing and building your own is it... 

[TERRA Operative]

I approve of this project. Actually, didn't Dave have a chip programmer design published years ago or something?
I'm sure there's a bunch of designs out there to choose from.

Also, when you are digging through your TTL chips, if you come across some 74HCT4518 chips, I needs them, I'll buy them from you immediately.

If Vince has none, if anyone else has any, please let me know!

[Vince]

Dear Terra,

Thanks to countless hours spent earlier this year sorting all my logic chips and many other components... I can now easily answer your question without even moving my butt from the computer chair, with only a couple mouse clicks ! Yeah, all that work sorting stuff is finally good for something, was worth it !! 

So... no sorry, I don't have what you want. the closest I have is a 4516 it's cloe cousin, but only vaniulla 4000 series form, no fancy 74HCT.
I just chceked on-line here and there, Farnell and Mouser, nope.. strange. Checked smaller outlets like Reichlets in Germany.. nope.
Checked a few French hobby tretailers... nope. Oh, finally found one :

https://www.e44.com/composants/composants-actifs/circuits-integres/circuits-integres-logiques-ttl/serie-74hct/ic-digital-bcd-up-counter-channels-2-dip16-74HCT4518.html

It's my "local" shop. Well, the one next town, 65 kms away from me. Too far to afford driving there, but I order stuff from them every now and then. They are fast by French small shops standard, shipped in 24 Hours usually !

Looks like they are aware of this strange shortage on the particular chip (do the Russians use it to make their rockets or what ?!  ), given they dare selling it for no less than 1.60 Euro a pop !! 

I see though, that the vanilla / 4000 series 4518 is plenty available though, for cents... can't you make that work in your situation ??

What do you need it for ? Fix some gear ? Working on a new design of your own ? Share schematics of the part of the circuit that uses this chip... maybe a vanilla 4518 could work, though I guess you have already investigated this route...

[m k]

Here's the other bugger from previous message.
After few hours of test it's still as accurate as ever, and eating the same 3.5 watts.

Seems that those grooved case edges at the back are not for power cables but for battery pack holders, option BP2, but after that my google was very uninformed.
3 pin DIN DC power connector has two + contacts and one bypasses the power switch, better that ways if battery pack blocks everything.

DC connector is also originally oriented, it's riveted.
I'm sure I saw flat top Phillips screws there.
(be noted that quiz difficulty can be affected if authority is very much disconnected)

Can't test the AC side right now, fuse is around 6.5 ohms without a visual wire and replacement is n/a, it's that very short glass tube.
Ready made adjustable AC overload thingy for low currents would be nice.

Inside is a tag indicating that the device is locally serviced '79, company is still alive and the tag has a number, maybe I can inquire what they did.
And were they also reading, like I did, that ACV selector is in 115V position, other one is 240V.
After a second thought the error should be eminent since there is only a single link.
Fuse was also still 250mA, when 115V version is 500mA.

Then last PSU hints.
It's named as a feed transformer, is from 70s and not from Soviets.

[capt bullshot]

Short term, why not try to make my own EPROM reader ? Just a simple reader, just for the most common old EPROM.

That reminds me of the good ol' days:
To save the time and effort to erase and program UV-EPROMs, I made this EPROM-Simulator (using some professional CAD and PCB manufacturing):



I don't have the specimen anymore, but old hardcopys of the layout and schematic, now scanned into an PDF. At the PC side, this thing was connected by a four core cable to the LPT, and used a simple program to shift the bits into its memory. I felt like a hero having this thing, as most other commercially available EPROM emulators were bulky and used a stiff 25 core cable. As a simple improvement, I've electrically isolated the unit from the PC by using three "high speed" optocouplers (6N136 or similar) to break nasty ground loops on the bench.

[capt bullshot]

Another memory from back then: This is a piece of "red" film they've used back in the days to expose the photosensitive coating of the PCBs during the manufacturing process.

[Vince]

I approve of this project. Actually, didn't Dave have a chip programmer design published years ago or something?

I remember that video of his, but I am pretty sure he designed a logic analyzer not a programmer.

[factory]

Here's the other bugger from previous message.
After few hours of test it's still as accurate as ever, and eating the same 3.5 watts.

Seems that those grooved case edges at the back are not for power cables but for battery pack holders, option BP2, but after that my google was very uninformed.
3 pin DIN DC power connector has two + contacts and one bypasses the power switch, better that ways if battery pack blocks everything.

DC connector is also originally oriented, it's riveted.
I'm sure I saw flat top Phillips screws there.
(be noted that quiz difficulty can be affected if authority is very much disconnected)

Can't test the AC side right now, fuse is around 6.5 ohms without a visual wire and replacement is n/a, it's that very short glass tube.
Ready made adjustable AC overload thingy for low currents would be nice.

Inside is a tag indicating that the device is locally serviced '79, company is still alive and the tag has a number, maybe I can inquire what they did.
And were they also reading, like I did, that ACV selector is in 115V position, other one is 240V.
After a second thought the error should be eminent since there is only a single link.
Fuse was also still 250mA, when 115V version is 500mA.

Then last PSU hints.
It's named as a feed transformer, is from 70s and not from Soviets.

That's a rare sight, a DMM2 that isn't broken. 
It explains why you mentioned the L1436 connector, they were still made back in 2009 and are the most fragile inside, tiny screws that can easily break off.

David

[Vince]

Short term, why not try to make my own EPROM reader ? Just a simple reader, just for the most common old EPROM.

That reminds me of the good ol' days:
To save the time and effort to erase and program UV-EPROMs, I made this EPROM-Simulator (using some professional CAD and PCB manufacturing):


I don't have the specimen anymore, but old hardcopys of the layout and schematic, now scanned into an PDF. At the PC side, this thing was connected by a four core cable to the LPT, and used a simple program to shift the bits into its memory. I felt like a hero having this thing, as most other commercially available EPROM emulators were bulky and used a stiff 25 core cable. As a simple improvement, I've electrically isolated the unit from the PC by using three "high speed" optocouplers (6N136 or similar) to break nasty ground loops on the bench.

Wow looks pretty neat Cap'tain, especially for such a long time ago ! Back then having access to CAD was not even in my wildest dreams. I could not even afford a UV eraser nor even just the UV tubes.
I remember all I could afford was a big UV "light bulb"... then I tried to cobble together a box for ti. Was a disaster, was not exactly good at making stuff with my hands...

My "CAD" was limited to a pen with special ink that you could use to draw tracks by hand directly onto a bare copper board, then etch it with that horrible chemical that I have no idea how to translate the name of in English. That horrible yellow brown stuff that eats your clothes instantly when you have even just a drip of the stuff on your T-shirt. Freaking scary stuff. I am glad these days are over. Really nasty stuff.

[factory]

I approve of this project. Actually, didn't Dave have a chip programmer design published years ago or something?
I'm sure there's a bunch of designs out there to choose from.

Also, when you are digging through your TTL chips, if you come across some 74HCT4518 chips, I needs them, I'll buy them from you immediately.

If Vince has none, if anyone else has any, please let me know!

None apparently, strange I found a regular CMOS (CD4518CN) version a few days ago, on that veroboard mod removed from the HP 5090B. 
Mouser only sell the 74HC version. 

David

[tautech]

My "CAD" was limited to a pen with special ink that you could use to draw tracks by hand directly onto a bare copper board, then etch it with that horrible chemical that I have no idea how to translate the name of in English. That horrible yellow brown stuff that eats your clothes instantly when you have even just a drip of the stuff on your T-shirt. Freaking scary stuff. I am glad these days are over. Really nasty stuff.

Ferric Chloride is what the memory cells seek from way back when we didn't really have anything else.

[Vince]

Yes must be that, looks very similar to the French name : " Perchlorure de fer "

[dl6lr]

Shot these two guys last year, when a real load was needed, not an electonic one.   
10Ohm/8A and 100Ohm 2A

"Im Winter glüh'n die Werkstattwände, hast Du Schiebewiderstände!"

[Vince]

J'comprends rien c'est normal ?? 

[vk6zgo]

J'comprends rien c'est normal ?? 

Είναι όλα ελληνικά για μένα!

[Zoli]

Értek amit értek, a többit hanyagolom; de nem kell sokat hanyagolnom.

And now, from the vault: my home built Willem(PCB3) programmer; I have the schematics, pdf PCB, dos/win programs; I've checked the timestamps, the newest is from 2002.
I will post them, once Vince present a working load on blue PCB 

[BU508A]

Also, when you are digging through your TTL chips, if you come across some 74HCT4518 chips, I needs them, I'll buy them from you immediately.

https://www.haje.nl/product_info.php/view/all/sort/3a/products_id/2202

HTH

[capt bullshot]

Wow looks pretty neat Cap'tain, especially for such a long time ago !

Thanks, I still wonder how I managed to make stuff that looked neat. Today I'm doing such (private projects) stuff more like "Jim Williams" style. While browsing through some old papers (where I found this one) I found another version of the same thing, with manual layout instead of autorouter layout (which this one is indeed). I guess I made it just because the manual layout looks better Can't remember if the manual layout PCB ever was fabricated.

Back then having access to CAD was not even in my wildest dreams. I could not even afford a UV eraser nor even just the UV tubes.
I remember all I could afford was a big UV "light bulb"... then I tried to cobble together a box for ti. Was a disaster, was not exactly good at making stuff with my hands...

I had an UV tube mounted on a wooden board, and a cardboard box to protect myself from the UV to erase EPROMs.

My "CAD" was limited to a pen with special ink that you could use to draw tracks by hand directly onto a bare copper board, then etch it with that horrible chemical that I have no idea how to translate the name of in English. That horrible yellow brown stuff that eats your clothes instantly when you have even just a drip of the stuff on your T-shirt. Freaking scary stuff. I am glad these days are over. Really nasty stuff.

I remember this technique well, and some bad experience (what a big mess this was) using ammonium persulfate. By some luck, I had access to said CAD and a professional PCB manufacturing facility through some generous person. Basically, I got PCBs manufactured for free in exchange for some computer and electronics related work I did for them.
Said CAD was a beast - it required a two monitor setup, one of them a standard "Hercules" text screen for the menus, and the other one a bigass Eizo Multisync with a purpose made ISA bus graphics card, running at 1024x768 pixels. The CAD software didn't work at all without this graphics card.

Once you had the schematics and layout done, you'd export either Gerber and S&M Drill, or (what was some kind of revolution back then) export PostScript, go to some printing shop (in the meaning of printing books and newspapers, not a copy shop), get a B/W film of your layout, the go to the PCB manufacturer, they'd make that "red film" from your prints to finally make the PCBs. One issue I've had is the absolute accuracy of the film printers that didn't match the absolute accuracy of the S&M drill data. The printers didn't understand that issue, said their films were correct though I could show the deviation using a ruler.

One of the projects I did for the PCB facility was a box that could read the drill data from a 3.5" floppy disk and send it through a serial port to the CNC drilling machine. It was planned to build some kind of network (no ethernet but rather kind of RS485) of a few of these boxes and a "server" (just a PC with a HDD)  that provided the data from a central repository to the CNC machines. That networked solution was never finished.

[Peter_O]

Shot these two guys last year, when a real load was needed, not an electonic one.   
10Ohm/8A and 100Ohm 2A

"Im Winter glüh'n die Werkstattwände, hast Du Schiebewiderstände!"

==>In winter the shop walls ar glowing in case you've got rheostats.

I just had an use case:
Wanted to change the selenium bridge rectifier in my Ruhstrat 25V transformer psu.




I had some used heat sinks at hand. But what size would be right for 8A max, which I consider a conservative limit for the old 10A transformers?

After some testing on the bench with an 400V 25A bridge at hand here we are:


After half an hour of 8A:


And back to the rheostat:


Its not glowing visibly but IR-wise at some 240°C.
Fortunally the limit of the rheostat is 8A too.  :-)

And btw. I'had tested the thermofuses. One didn't break the circuit at no current at all, the other was kind of very reluctant.
So I put in new ones for 8A and 4A for the small 6V output.

Maybe I will add some additional fuse holders to be able to put in fuses as needed in specific situations.

[TERRA Operative]

Dear Terra,

Thanks to countless hours spent earlier this year sorting all my logic chips and many other components... I can now easily answer your question without even moving my butt from the computer chair, with only a couple mouse clicks ! Yeah, all that work sorting stuff is finally good for something, was worth it !! 

So... no sorry, I don't have what you want. the closest I have is a 4516 it's cloe cousin, but only vaniulla 4000 series form, no fancy 74HCT.
I just chceked on-line here and there, Farnell and Mouser, nope.. strange. Checked smaller outlets like Reichlets in Germany.. nope.
Checked a few French hobby tretailers... nope. Oh, finally found one :

https://www.e44.com/composants/composants-actifs/circuits-integres/circuits-integres-logiques-ttl/serie-74hct/ic-digital-bcd-up-counter-channels-2-dip16-74HCT4518.html

It's my "local" shop. Well, the one next town, 65 kms away from me. Too far to afford driving there, but I order stuff from them every now and then. They are fast by French small shops standard, shipped in 24 Hours usually !

Looks like they are aware of this strange shortage on the particular chip (do the Russians use it to make their rockets or what ?!  ), given they dare selling it for no less than 1.60 Euro a pop !! 

I see though, that the vanilla / 4000 series 4518 is plenty available though, for cents... can't you make that work in your situation ??

What do you need it for ? Fix some gear ? Working on a new design of your own ? Share schematics of the part of the circuit that uses this chip... maybe a vanilla 4518 could work, though I guess you have already investigated this route...

I need them for the option board I'm building for my function generator (Schematic linked below), I can get HC versions, but they use CMOS voltage levels, not TTL that the HCT use, so I'm not sure if HC will work (I'll have to try them out).
Looks like your store only allows the purchase of two, but I need three!

I approve of this project. Actually, didn't Dave have a chip programmer design published years ago or something?

I remember that video of his, but I am pretty sure he designed a logic analyzer not a programmer.

Ah yeah, that was it. I knew it was something like that anyway.

Also, when you are digging through your TTL chips, if you come across some 74HCT4518 chips, I needs them, I'll buy them from you immediately.

https://www.haje.nl/product_info.php/view/all/sort/3a/products_id/2202

HTH

They got the stuff, but with 30euro shipping charge for international shipping.....

[Vince]

And now, from the vault: my home built Willem(PCB3) programmer; I have the schematics, pdf PCB, dos/win programs; I've checked the timestamps, the newest is from 2002.
I will post them, once Vince present a working load on blue PCB 

HMMMMM !!! Putting pressure on me I see !! I am up for a challenge !! 

However I am not sure I deserve this.... it's way too sophisticated, luxurious for me : can program rather than just read. Has fancy things like DIP switches, LEDs, even a ocal voltage regulator with cute tiny little heat sink...

I will use yours in the short term THEN later I will take some time to try to design my own as well for fun !