@@kakurerud7516 . Lol yeah i found it a little odd. Normally it's all complaining about stuff that is bodged (especially with cheaper products) and all of a sudden it's a nice looking mod?
Never mind mod boards, what's coming up in the old arcade game scene is custom ICs. Well, not _really_ ICs. They're little boards that replicate the functionality of failed custom so-called hybrid chips. Usually SIP, ceramic substrate, always encapsulated. The two I've got was a video DAC/buffer and the other did audio mixing for music and sound effects. It was once thought that once these custom components are gone, that's it. Fortunately there's guys out making replacements.
urdnal I’ve bought similar boards for old synthesisers. There’s a guy in Belgium makes replacement VCF and VCO boards for the Roland Juno 106 that basically keep these things alive when the resin on the originals goes conductive and kills it.
@@cozzm0AU Correct. I have a Xexex board, which has the same hybrid, the Konami 054544. I think these require transferring the 054321 ASIC from an original, since I don't think that's been reverse engineered yet. I haven't needed this one yet, the audio module I needed is on a Raiden II board. For my Xexex I have a repro 054573 RGB DAC.
I know what you mean about repairs/replacements for military and defence. Also some backwards compatibility had to be part of the design of some sub-assemblies. The company I worked for had to include (as part of the purchase agreement and contract) an assurance that we could repair, supply, maintain or replace everything down to component level for 10 years after date of installation. Bodge wires and mod boards would be used regularly to overcome very real obselesence issues out in the field.
I love these "how to do it" videos, Dave. One thing to note - some products such as wifi and bluetooth interfaces are designed from the start to be used like mod boards, placed down on your design from trays. Vendor gives pad layout for castellations, etc. I dont know how common it is, but we use one that way! We can use that mod board on a number of different designs, making changes to it independently of the main board.
I used to work at Philips electronic in Montreal. We built PCs, and did our own board assembly. Being a high volume shop (~500K motherboards a year, and a similar quantity of VGA graphics card), the standing rule was that one mod wire would force a board re-spin. We would use up existing inventory of PCBs, and the next order would have the new artwork. Somebody internally did the math, and figured out that the manual labour to add a mod wire, and the bottlenecking of the production lines was always a higher cost than the re-spin cost. Also, after about a year, MELF packages were banned. In our case, they were used for diodes and a few capacitors, and sue to their shape, gave the pick and place equipment (Fuji CP III and CP IV) a lot of problems, and they tended to roll off of their pads when moving down the conveyor line.
@@xenonram We called it a board re-spin. Any time the board layout changed, for whatever reason, it was called a re-spin. We kept track of the artwork changes by changing the board revision number, but the act of changing the artwork was called a re-spin. I don't know if this was industry wide terminology, but those were the terms we used internally.
Thanks Dave, this is super useful! I recently created a PCB in my last video and the problem I had was getting the PCB fab to cut the castlated edges - what I was missing was the idea of panelising it, and I had no v-scores. That would have helped I think. I will do this in the revision.
I would think you could put plated through holes down, laying halfway over the dimension outline, select tab routing, and leave a note in additional comments that it is on purpose?
For panelised thin PCBs undergoing pick and place, it can be easiest/cheapest to break out the circuits from a number of sacrifical panels and glue the panels together until thick enough to be stiff and act as the back support for a panel being populated.
In the UK electronics industry (HP), we used the terms 'kluge' or 'kludge' for an add-on mod like this. Wikipedia gives lots of possible sources for these words dating back even as far as WW1. If a mod is a bit 'kludgy', it generally means it's a bit of a bodge, but it works. The Scottish slang for toilet is 'cludgie' :o) OTOH, a kluge pcb can be a valid way to a nice result, as with Dave's 121GW meter mod here, imho. Thumbs up !
Nice video - very important subject! When you were showing the game mod boards, I remembered a design by Koichi Nishida of a Apple II disk drive emulator for the IIc: it fits inside the case perfectly!
This what great! If you ever do a follow up, I'd love to see the actual attachment to the original board (I know its just soldering ... but I've learned the hard way about how important technique is, so I'd love to see an example from someplace I trust). Thanks for the great content!
I noticed that with the new background, you get to use those shelves for ephemera you like, while using the library layout shelves off-screen for actual Mailbag items!
at a previous employer we we building 40 small detectors for a large company who has to remain nameless, anyway on a really tight deadline when we went to start assembly the supplier had sent sot23 versions of a particular part, not having a substitute part and not enough time to re order we just used those little adapter boards, in the end it worked out better since battery life improved and sensitivity increased, not mega amounts but noticeable, in fact the "bodge"board became a service replacement when refurb and service was done on older units.
the copper filling external of the actual pcb also helps for stability in the flexibility of the pcb, for some non standard sizes, sub 1mm boards, you need copper as much as possible to have some rigidity in your board, else it becomes some kind of flexible plate where pick and place becomes a nightmare
Since you have not mentioned it: Are these two transistors in a voltage-clamp configuration just like you explained in the previous video? It really seems so. Was the previous clamp part too expensive, has it produced problems in the circuit, or why was that mod neccessary?
Yes, it's just for improved performance on the high resistance ranges, and yes it's cheaper. And will eventually be rolled out onto a new board design. New stock meters come with this board fitted. And no, existing users cannot retrofit it, as it would require complete re-calibration on certain ranges, and there is no reason to do so anyway. Designs often get tweaked like this and slight improvements made with time.
@@EEVblog Were you using a TVS on that spot and had leakage problems? It´s the only thing, I that I can think of, being more expensive than this solution and still have this problems. Also package seems to be around that range.
@@warrenmasters3036 What? Own more than one of a brand of meter? That's ridiculous! (for those that don't know me, this remark is a big "tongue in cheek" joke. I'm all for buying duplicate test equipment)
@excited box Bought a $10 v/ohm meter for learning electronics and later that day saved myself $70 in unnecessary repair costs. Hard to argue against having some tool over having no tool.
I don't want to sound critical, I'm just bringing this to your attention, this video gives me the "green screen" feeling for the background in the intro, I think there is too much light on you Dave.
Hi Dave, I am doing an obsolescence job at the moment for a obscure SO8 watchdog chip. I have found an SO8 AVR microcontroller that has power supply pins in the right place. It has onboard rc oscillator, programmable voltage detector, so with software for watchdog emulation so its going to be the replacement, no mod board required!
Honestly, I've only watched a minute or two and have no idea what you're talking about, well, some things, but stuck a like as I dig your vids man. Keep up the good work!
3:45 spotted Tim "Viletim" Worthington's N64 RGB flex PCB. Should have included a pic of UltraHDMI. My brother and I have installed hundreds of those upgrades for N64. :)
The pick n place machines I've worked with have had magnetic support pegs you place under the board during setup to help support it. Same with the solder paste dispense machine
@@andrewwhite1793 The machine indexed each board into the same place when loaded, and the pins underneath never move, aside from when it pulls them away to eject the board
@@EEVblog I was talking about all the blown away passives around the former mod PCB ;). But yeah, that happens. Had to replace some TQFP uCs on prototypes once and just put new blocking caps around them afterwards.
Any general rules to follow when making a castellated design, like the hole diameter/pad size/plating specs to look for? Obviously the trace width and location need a bit of attention. I still haven't ordered anything from a board house yet but am learning a lot of fun stuff from etching a my own circuits from scratch. This looks like a valuable thing to bank for later use. From my experience thus far, it would seem quite easy to have a pad lift while soldering a badly designed or badly executed castellated pad. Thanks for the upload :) -Jake
Re: Console mods -- there are a lot of bad mod chips that make you run wires everywhere, but the cool convoluted shaped ones that fit the exact foot print and just get soldered in place, like you mentioned, are freaking slick! -- Voultar has some videos on his channel of repairing poorly modded ebay consoles with such chips -- this one is pretty cool: ua-cam.com/video/TDwroVnXFH4/v-deo.html -- he does still have to add a few stray wires for some of the chips -- but the before and after on the hucard slot is amazing; and he's got lots of little boards like that featured in his various videos. 😊
Great useful idea. Never thought about that.. :D But used it to.. One time, when i created prototype PCB, i didn't spot mistake - in software database was component pin mismatch for voltage regulator in sot223 case.. after soldering and joins verification, aplied power and tested with multimeter, voltage regulator not regulating as it should.. ok, first idea, replace regulator, same result.. then i started verifying schematic, all ok and when i manually start to compare pinout, datasheet and board, i find out that pins in database are opposite.. :D First idea, new board with error correction, second idea - create new mini board to hold regulator and to match existing board.. And finally i create it in quick'n'dirty method manually with permanent marker on a small board 10x10mm, etched and soldered it in the place of old version's regulator.. All worked and i soldered in all chips.. (I love to use steps when creating something from scratch and that's why i didn't fried any chip - first step is power rail check).. Second time when i use this method, board was bigger and with more part's - i replaced unknown, dead smd chip for backlight driver in GPS navigator.. That was comlex project because space in enclosure was limited, lot of research with scope to understand what exactly this chip originally was doing, pcb examination, some reverse engineering.. But at the end all worked as it should with brightness regulation and power control from mainboard.. GPS was alive again and i had a fun.. :) Thumbs up, as always, for great video with good, useful points and for reminding this method.. :)
• They're also called adapters. • Not all game-console mods are for piracy; they also allow homebrew (dev consoles are expensive), but also more common mods like HDMI outputs and such for old consoles. (Voultar has lots on his channel.) • For a moment there, I thought that board you held up was transparent because of green-screen?
If you moved the mini-boards closer together and just used V-Scoring rather than routing between cards, you could get many more cards side by side, and then use V scoring between the top of one row and the bottom of the next row, which could gain you a few more rows of usable cards. You could castellate a via so the top half goes to one card, and the bottom half to another card. Why reduce your output? I assume there are real reasons.
I wonder how big the market is for mod boards. There are plenty of obsolete parts still used for hobbyists and common repairs. Is there a database where you can search for an (obsolete) part and find the buy link for the replacement? It does not need to only offer mod boards, but all kind of items you could replace a given part with.
L3 P3 Really good question. In the old days there used to be entire books of equivalent component numbers for ready look up. Not sure about these days.
For example I recently saw this www.leobodnar.com/shop/index.php?main_page=product_info&cPath=125_127&products_id=324 board to replace an unobtanium prescaler IC in a HP/Agilent signal generator. Useful if you have a need for exactly that IC (which apparently fails quite often).
why is the no mask zone of the fiducial square and round on the other one? does it help for orientation? ( thought that having 3 fiducials was enough to avoid problems)
In the 80s a mate used to improve output stages on synthesizers by replacing the nasty factory OpAmps in TO99 metal cans with a daughter board with a higher spec OpAmp and some magic, including shielding (shielded signal path), and a little heater circuit because thermal instability was a problem. He used to make good beer money once word got around.
I don't understand how the pick-and-place machine uses the mod boards in production. Does the machine break them off the larger board you showed and then place them? Or, does someone have to break them off manually and then put the little mod boards into some kind of a magazine? Thanx
Someone has to break them and place them in custom trays. If you weer serious you would do this, but most likely easier to simply hand solder the part.
@@henryD9363 I was confused at first. When he was talking about putting that board into the P&P machine, he was talking about putting the components onto the mod board (populating the mod boards with components), not putting the mod boards onto a main board.
In the defence industry, finding replacements for obsolete parts can be a real challenge. Especially for older systems where there's not enough documentation. Legacy platforms and systems are a real pain.
@@EEVblog Especially because there is a whole business model catering to defence industry that will try to sell you that shitty jellybean germanium transistor at ridiculous price because they bought out all the stock from the parts market.
@@EEVblogthere was one recent example I know of where an engineer was asked if a particular power resistor could be used to replace an obsolete one but there was only an assembly instruction for the equipment, no dimensions or anything. It was considered finding the platform that this equipment was fitted to and finding out that way but it really was not worth the engineer's time to do that. Shame really... the defence industry (at least where I live) is really behind the times in terms of obsolescence management and legacy management.
I did this job for a few years and it was a right royal pain in the neck. I had bosses expecting pin for pin replacements on tech which was completely obsolete. Gallium transistor type obsolete in some cases. With simple stuff like op-amps there was often a similar device but rarely in automotive grade (-40 to +125C temp range) never mind full military (-55C to +125C) and rarely in ceramic packaging (the ceramic package helps match the coefficients of expansion between the chip and everything else). Then try getting one to MIL-STD-883/B.
Will there be a video talking about the mod you made to the 121GW? I made a mod board for a Motorola D2 Evaluation kit a few decades ago. The board allowed me to plug a 6809 CPU in to the 6800 CPU socket on the main board.
Thoughout the video, you can see all the layers on the PCB, is it still financially more practical to make it wil that many layers over just having a single, thick board?
It's really an "add board", because it can only add wires/components. But sometimes you want to remove traces, and switch where they go. What can you do? Cut traces and then "add board"?
Like when people hear that america spends 750 billion on defence. They assume its like buying weapons or something. What they miss, is that a large percentage of this is just maintenance. It cost alot to keep military equipment going. Spare parts in that 750 billion, is a massive chunk of this. People always seem to assume, america is spending all there budget just on buying or building new weapons. When probably a massive chunk of there budget is just spare parts. So its not surprising to hear about a lesser military having techs that keep older military gear going longer. So in real world, america is spending a small percentage on rnd, and actually buying new weapons. But people assume when they hear these massive numbers, america must be doing massive amounts of research, and developing weapons, when a large percentage of there budget is just like spare parts, and maintenance.
I needed a mod board to replace an obsolete SOP8 with a SOT 23-5. My first problem was finding a board house that did castellations. Then they would not get small enough, so I have grind one side on a grinder to get the other side castellations. This was a couple years ago, but I ended up going with OSHPark. It's a high side switch. Pic of it here: imgur.com/a/u41l9bp
Yes and no. There are some standards for some specific systems like VME, and the PC104 format (which I think is now obsolete), and for PC motherboards of course like ATX size etc. However for a lot of applications there is no standard. EG in the automotive industry I did not design any two boards the same size. Even boards doing the same job for different customers were different shapes often due to connectors. The only place I know of with standard sizes (sort of) is panel size for the PCB's to be etched on. One of the sizes is roughly A4 size and often the PCB design is fiddled with to get the maximum number of PCB's per panel. Basically it's one long session of jiggery pokery start to finish.
Interesting and timely. I want to do a board that is about that size. Its to replace an SMD crystal in an HC-49/S SMD package. I was wondering how I can get a board that is only 12x4mm made.
Same as any other. Just make sure you have it populated before it is depanelized. I.e., if your pcb manufacfurer and your assembly house are not the same company, be sure you order your pcb as complete panels!
Cool video. With our customers it's rare to see them making an extra board for a mod, most of the time it's just a bunch of bodge wires ;^) Also Dave, how are you planning to roll the 121GW mod boards to those that already have the DMM?
I'm guessing the modboard is to make up for a supply deficiency (the part went out of production?), not a design flaw, so there should be no problem for existing units
He mentioned in another comment it is only for new builds and not for those already in customer's possession, as if you do the mod on your tool it will require recalibration on multiple circuits. And the mod is an upgrade, not something your tool necessarily needs.
Was it actually economical to pick and place a board like this? It doesn't seem like you needed them in quantity really so the setup costs alone seem like they would have been excessive per board.
@@EEVblog Ah sorry I wasn't very clear. I mean in this example with the board you were handling for most of the video, the one which only contains the clamping transistor pairs. I was curious how many of those you actually needed populated by pick and place and if that was economical. After all how many of those sheets did you ultimately have populated compared to the tooling and setup costs?
Illegal console mod boards? Mate, you live in Australia. Those things were ruled to be legal here due to consumer protection laws. XD Then again, we DID sign the DMCA after that point, so who even knows anymore. These kind of boards remind me of the kinds of things you need to make/buy to be able to use certain kinds of parts for hobbyist or experimental purposes. It can be pretty difficult for many components to still find through hole DIP packages - especially for more complex parts such as say, a CPU or FPGA. Sure the reasons aren't a huge surprise, since the pin count can quickly explode. (consider if you had a 4 gigabyte RAM chip with a full old-school parallel address bus - that's at least 8 data pins, a minimum of one power and ground pin, a read and write pin, probably a chip select pin, and 32 address lines - that's at least 44 pins, which strains against the limits of practicality for a DIP package, and of course is huge in such a package for good measure.) So... To deal with BGA or even a typical QFP in a hobbyist, one-off or experimental context almost REQUIRES the use of mod boards to bring it to a more reasonable form factor.. Sure it depends on what, exactly you're doing, but more often than not, this is the only way to reasonably use such parts in that kind of context...
Another great video, thanks Dave. I'm wondering if there's such thing, similar to the through hole matrix breadboard prototype type PCBs you solder to, but for surface mount.. I seem to be accumulating loads of surface mount things but.. not really sure what I'm doing with them!
There is a few options on ebay, but, for the most part seem to be outrageously priced.. ..speaking of which, digikey also has a vast stock of proto boards, i wasnt looking for surface mount in particular, but, they would probably be your best bet as they are a reputable source.
@@topherteardowns4679 thanks, I'll keep my eyes open then! I have various proto boards, the strip and matrix ones anyway. Perhaps I can figure out another way to use them with surface mount.. I trying to avoid buying a bunch of breakout boards and such for something I'll inevitably mess up 🤣 I bet I can repurpose small pieces of strip board or so and make little pieces like Dave or something ☺️
@@ollieb9875 yeah, I always buy cheap proto boards when I see them, just because they are cheap and can be used for a limitless number of projects -I even use smd chips on the standard .1 hole proto boards.. Sometimes its a pain in the ass, other times it is much much much more beneficial than either trying to find the niché adapter or making a board and spinning it in FR4 pcb. If I comr across the seller/order i recently got of the smd proto, I will reply here with the keywords to search
@@topherteardowns4679 I think I saw some on mouser.co.uk (being in the UK) SMT proto or breadboard, something like that, but never really looked properly.. I'm making some things for Christmas so will look tomorrow, but I may just do as you say and use what I have if they're too expensive ☺️ Cheers!
I've been working on a handheld gaming machine using a SBC (Lattepanda), and I found that there's a ton of nice 2K LCD modules on aliexpress that come with this generic MIPI to HDMI driver board. Some chatter about people trying to design these boards on the forums, and on GitHub, but all abandoned. I was originally thinking of designing some sort of FFC to connect the HDMI from the driver board to the SBC (perhaps with a "repurposed" HDMI switch in between so I can still have an HDMI connector somewhere on the thing). I've never designed an FFC one, and they seem expensive. Do you think it might be possible to create a modboard to replace the connector instead, or am I going to destroy it when attempting to solder onto the HDMI connector pads? Maybe there's a better technique?
Do you need the processing power of the Latte Panda? The R Pi has some really nice touch screens available and they are really low power. Also what do you mean by FCC? Flat Conductor Cable? There are that I know of at least 12 uses of that acronym in the electronics industry. I'm presuming the LCD screens have MIPI interfaces? One of the reasons they might be so cheap is that HDMI to MIPI interfaces cost a fortune relatively speaking. IE the cheapest I know of is £50+. I have a Pi with one of these www.raspberrypi.org/blog/the-eagerly-awaited-raspberry-pi-display/ and it cost about £80 a while back. Not 2k but it works well.
@@gordonlawrence4749 I really need an x86 processor. The pi 3b+ is a brilliant board without a doubt but I'd really like to be able to run windows x86 apps. The 2 lane MIPI connector on the pi is also a real drag. It just can't push out as many pixels as HDMI, but what's the alternative if not these relatively expensive driver boards? It seems only proprietary drivers and driver boards exist in both the pi ecosystem and elsewhere when it comes to MIPI.
@@gordonlawrence4749 and yeah, I was talking about designing a flex connector like Dave was talking about in the video, but while they're great on space they seem to be an expensive pain in the ass.
If you want some examples of what these are used for in the console space, other than the old piracy chips, this site has a good selection of the video quality upgrade kits, generally used to get a decent RGB signal out of old consoles that used composite/RF; www.oldskoolconsoles.com/shop-2 Not associated, just first link that showed up for me :)
some larger parts can, small components simply sit and stay in the solder paste which is applied to a board before placing all the parts. the surface tension holds them ok. this kind of stuff is usually on machines and conveyors so they aren't moving far and people (generally) can bump them and stuff.
Copper is reflective and highly thermally conductive, so it takes a huge amount of laser power to cut. The fiberglass substrate probably could, though! I'll have to try that.
Maybe, maybe not... The way PCB manufacturing was explained to me was you started with really thin copper then plated extra copper onto the parts that were going to be used, then masked that and etched away the unwanted parts. Excess copper fill would be a waste as it would need plating even if it was not used. Obviously this doesn't apply to DIY jobs.
@@boristheengineer5160 I have never heard of PCB plating copper onto the board. I was under the impression the boards come with a laminated sheet of copper already glued on.
@@MyuFoxable The laminate would have a reduced thickness of cu compared to the final PCB. To get through-plating the PCB would be drilled right at the beginning then would be treated somehow to make the insides of the holes conductive. The resist would be applied in reverse, exposing the places where copper was required. Then plating would thicken the tracks to the required thickness and coat the holes. It would still need a conventional etch at the end to remove the unwanted thin copper. It stuck in my mind because it was almost the reverse of the classic etching process I'd always read about and used a bit for prototypes.
Your videos are awesome .. This one is no exception. However, it would be very kind of you to tell me what is that device in the background, on the left side of the screen, under the registration plate saying: "OUTATIME". The one with the keyboard on it ... The device keeps distracting my attention.
You managed to do whole video about this topic without using the word "bodge", I'm really impressed :D
.. its not a bodge when he does it. ; )
@@kakurerud7516 . Lol yeah i found it a little odd. Normally it's all complaining about stuff that is bodged (especially with cheaper products) and all of a sudden it's a nice looking mod?
I'm pretty sure he did say the word "bodge" once
Ahh our favorite eevblog words: bodge and dodgy.
@@BillAnt a thing of beauty is a joy forever! ;)
Only five minutes in & we've got MELF on MELF action! This is going to be good!
Xy Zi - Melf Porno :-)
Never mind mod boards, what's coming up in the old arcade game scene is custom ICs. Well, not _really_ ICs. They're little boards that replicate the functionality of failed custom so-called hybrid chips. Usually SIP, ceramic substrate, always encapsulated. The two I've got was a video DAC/buffer and the other did audio mixing for music and sound effects.
It was once thought that once these custom components are gone, that's it. Fortunately there's guys out making replacements.
NVRAM! nvram.weebly.com =D
Replacing the audio hybrids on boards like Xmen ??
urdnal I’ve bought similar boards for old synthesisers. There’s a guy in Belgium makes replacement VCF and VCO boards for the Roland Juno 106 that basically keep these things alive when the resin on the originals goes conductive and kills it.
@@cozzm0AU Correct. I have a Xexex board, which has the same hybrid, the Konami 054544. I think these require transferring the 054321 ASIC from an original, since I don't think that's been reverse engineered yet. I haven't needed this one yet, the audio module I needed is on a Raiden II board. For my Xexex I have a repro 054573 RGB DAC.
There should be more people repairing good old stuff like that.
Call it what it is Dave. It's a bodge, plain and simple ;)
Yes, but its an M&S bodge
I know what you mean about repairs/replacements for military and defence. Also some backwards compatibility had to be part of the design of some sub-assemblies.
The company I worked for had to include (as part of the purchase agreement and contract) an assurance that we could repair, supply, maintain or replace everything down to component level for 10 years after date of installation.
Bodge wires and mod boards would be used regularly to overcome very real obselesence issues out in the field.
I love these "how to do it" videos, Dave. One thing to note - some products such as wifi and bluetooth interfaces are designed from the start to be used like mod boards, placed down on your design from trays. Vendor gives pad layout for castellations, etc. I dont know how common it is, but we use one that way! We can use that mod board on a number of different designs, making changes to it independently of the main board.
I used to work at Philips electronic in Montreal. We built PCs, and did our own board assembly. Being a high volume shop (~500K motherboards a year, and a similar quantity of VGA graphics card), the standing rule was that one mod wire would force a board re-spin. We would use up existing inventory of PCBs, and the next order would have the new artwork. Somebody internally did the math, and figured out that the manual labour to add a mod wire, and the bottlenecking of the production lines was always a higher cost than the re-spin cost.
Also, after about a year, MELF packages were banned. In our case, they were used for diodes and a few capacitors, and sue to their shape, gave the pick and place equipment (Fuji CP III and CP IV) a lot of problems, and they tended to roll off of their pads when moving down the conveyor line.
That's not really re spinning, if you used up the stock. It's more of an upgrade or revision.
I don't think they ever made a VCR without at least one mod wire
Yep MELF stands for MEtal film Leadless Ferfacksakeitrolledoffagain.
@@xenonram We called it a board re-spin. Any time the board layout changed, for whatever reason, it was called a re-spin. We kept track of the artwork changes by changing the board revision number, but the act of changing the artwork was called a re-spin. I don't know if this was industry wide terminology, but those were the terms we used internally.
Thanks Dave, this is super useful! I recently created a PCB in my last video and the problem I had was getting the PCB fab to cut the castlated edges - what I was missing was the idea of panelising it, and I had no v-scores. That would have helped I think. I will do this in the revision.
I would think you could put plated through holes down, laying halfway over the dimension outline, select tab routing, and leave a note in additional comments that it is on purpose?
how can one single human being have so much professional knowledge
For panelised thin PCBs undergoing pick and place, it can be easiest/cheapest to break out the circuits from a number of sacrifical panels and glue the panels together until thick enough to be stiff and act as the back support for a panel being populated.
"Board" - the fine line between "Bodge" and "Mod"
In the UK electronics industry (HP), we used the terms 'kluge' or 'kludge' for an add-on mod like this. Wikipedia gives lots of possible sources for these words dating back even as far as WW1. If a mod is a bit 'kludgy', it generally means it's a bit of a bodge, but it works. The Scottish slang for toilet is 'cludgie' :o) OTOH, a kluge pcb can be a valid way to a nice result, as with Dave's 121GW meter mod here, imho. Thumbs up !
Nice video - very important subject! When you were showing the game mod boards, I remembered a design by Koichi Nishida of a Apple II disk drive emulator for the IIc: it fits inside the case perfectly!
Never heard of this outside of a daughter board as part of the initial design for space/layout constraints. Very cool!
These kinds of videos are the reason I still watch UA-cam, and pay for it, hope I'm not an unnoticed minority from the parent company perspective.
Thanks I hope so too!
This what great! If you ever do a follow up, I'd love to see the actual attachment to the original board (I know its just soldering ... but I've learned the hard way about how important technique is, so I'd love to see an example from someplace I trust).
Thanks for the great content!
Hey Dave(s)
8:48
Upload referenced:
ua-cam.com/video/VXE_dh38HjU/v-deo.html
(And for good measure)
Dave's "PCB Design & Manufacture" playlist:
ua-cam.com/play/PL8D3B363139B67FF3.html
I noticed that with the new background, you get to use those shelves for ephemera you like, while using the library layout shelves off-screen for actual Mailbag items!
at a previous employer we we building 40 small detectors for a large company who has to remain nameless, anyway on a really tight deadline when we went to start assembly the supplier had sent sot23 versions of a particular part, not having a substitute part and not enough time to re order we just used those little adapter boards, in the end it worked out better since battery life improved and sensitivity increased, not mega amounts but noticeable, in fact the "bodge"board became a service replacement when refurb and service was done on older units.
Been there!
the copper filling external of the actual pcb also helps for stability in the flexibility of the pcb, for some non standard sizes, sub 1mm boards, you need copper as much as possible to have some rigidity in your board, else it becomes some kind of flexible plate where pick and place becomes a nightmare
Since you have not mentioned it: Are these two transistors in a voltage-clamp configuration just like you explained in the previous video? It really seems so.
Was the previous clamp part too expensive, has it produced problems in the circuit, or why was that mod neccessary?
Yes, it's just for improved performance on the high resistance ranges, and yes it's cheaper. And will eventually be rolled out onto a new board design. New stock meters come with this board fitted.
And no, existing users cannot retrofit it, as it would require complete re-calibration on certain ranges, and there is no reason to do so anyway.
Designs often get tweaked like this and slight improvements made with time.
@@EEVblog GREAT! Now I have an excuse to buy a new one!
@@EEVblog Were you using a TVS on that spot and had leakage problems? It´s the only thing, I that I can think of, being more expensive than this solution and still have this problems. Also package seems to be around that range.
@@warrenmasters3036 What? Own more than one of a brand of meter? That's ridiculous!
(for those that don't know me, this remark is a big "tongue in cheek" joke. I'm all for buying duplicate test equipment)
@excited box Bought a $10 v/ohm meter for learning electronics and later that day saved myself $70 in unnecessary repair costs. Hard to argue against having some tool over having no tool.
I don't want to sound critical, I'm just bringing this to your attention, this video gives me the "green screen" feeling for the background in the intro, I think there is too much light on you Dave.
Hi Dave, I am doing an obsolescence job at the moment for a obscure SO8 watchdog chip. I have found an SO8 AVR microcontroller that has power supply pins in the right place. It has onboard rc oscillator, programmable voltage detector, so with software for watchdog emulation so its going to be the replacement, no mod board required!
Honestly, I've only watched a minute or two and have no idea what you're talking about, well, some things, but stuck a like as I dig your vids man. Keep up the good work!
An improvement would be to route the half holes and have the v-scoring on the other side. Less risk of tearing up the holes.
The Altium "funky board design" on the back!
Nicely spotted
Somebody had to sneeze in the reflow oven
Just bought my first osciloscope... Love your videos! You´re awesome ahah
3:45 spotted Tim "Viletim" Worthington's N64 RGB flex PCB. Should have included a pic of UltraHDMI. My brother and I have installed hundreds of those upgrades for N64. :)
The pick n place machines I've worked with have had magnetic support pegs you place under the board during setup to help support it. Same with the solder paste dispense machine
Hi, how did you make sure the pins were put in the same place for each run of the same PCB?
@@andrewwhite1793 The machine indexed each board into the same place when loaded, and the pins underneath never move, aside from when it pulls them away to eject the board
You didn't really save on the hot air while removing on of these boards on the scope board, or did you?
The mod PCB actually *crumbled* when it came off, it was a mess! Must have been some horrible quality non-woven fibreglass.
I was staring at those for a minute thinking, damn that is a horrible botch job, before realizing it was just from him removing the mod board.
@@EEVblog I was talking about all the blown away passives around the former mod PCB ;). But yeah, that happens. Had to replace some TQFP uCs on prototypes once and just put new blocking caps around them afterwards.
Looks like a crime scene 6:36
Yeah, shit happens. No worries.
Any general rules to follow when making a castellated design, like the hole diameter/pad size/plating specs to look for? Obviously the trace width and location need a bit of attention. I still haven't ordered anything from a board house yet but am learning a lot of fun stuff from etching a my own circuits from scratch. This looks like a valuable thing to bank for later use. From my experience thus far, it would seem quite easy to have a pad lift while soldering a badly designed or badly executed castellated pad.
Thanks for the upload :)
-Jake
Re: Console mods -- there are a lot of bad mod chips that make you run wires everywhere, but the cool convoluted shaped ones that fit the exact foot print and just get soldered in place, like you mentioned, are freaking slick! -- Voultar has some videos on his channel of repairing poorly modded ebay consoles with such chips -- this one is pretty cool: ua-cam.com/video/TDwroVnXFH4/v-deo.html -- he does still have to add a few stray wires for some of the chips -- but the before and after on the hucard slot is amazing; and he's got lots of little boards like that featured in his various videos. 😊
I like the new studio. Nice!
6:20 it looks like they just threw some capacitors just above your stylus :-O
Crash soldering ? :)
Dave ripped up one of the pads next to the marking TC1000. Hopefully it wasnt needed.
@@mrlithium69 It was a scrap PCB...
@@mrnmrn1 Yes, it's a scap PCB, zero care factor. The mod board *crumbled* when it was removed, it was a mess.
I thought this was the ugly style mod, before the mod board
Coincidentally, I’m in the process of exactly that in an old through hole design. Luckily, there’s plenty of room for the 1” x 1.5” mod board.
Great useful idea. Never thought about that.. :D
But used it to.. One time, when i created prototype PCB, i didn't spot mistake - in software database was component pin mismatch for voltage regulator in sot223 case.. after soldering and joins verification, aplied power and tested with multimeter, voltage regulator not regulating as it should.. ok, first idea, replace regulator, same result.. then i started verifying schematic, all ok and when i manually start to compare pinout, datasheet and board, i find out that pins in database are opposite.. :D First idea, new board with error correction, second idea - create new mini board to hold regulator and to match existing board.. And finally i create it in quick'n'dirty method manually with permanent marker on a small board 10x10mm, etched and soldered it in the place of old version's regulator.. All worked and i soldered in all chips.. (I love to use steps when creating something from scratch and that's why i didn't fried any chip - first step is power rail check)..
Second time when i use this method, board was bigger and with more part's - i replaced unknown, dead smd chip for backlight driver in GPS navigator.. That was comlex project because space in enclosure was limited, lot of research with scope to understand what exactly this chip originally was doing, pcb examination, some reverse engineering.. But at the end all worked as it should with brightness regulation and power control from mainboard.. GPS was alive again and i had a fun.. :)
Thumbs up, as always, for great video with good, useful points and for reminding this method.. :)
I have it on reliable authority that MELF stands for MEtal film Leadless Ferfacksakesitrolledoffagain.
• They're also called adapters.
• Not all game-console mods are for piracy; they also allow homebrew (dev consoles are expensive), but also more common mods like HDMI outputs and such for old consoles. (Voultar has lots on his channel.)
• For a moment there, I thought that board you held up was transparent because of green-screen?
If you moved the mini-boards closer together and just used V-Scoring rather than routing between cards, you could get many more cards side by side, and then use V scoring between the top of one row and the bottom of the next row, which could gain you a few more rows of usable cards. You could castellate a via so the top half goes to one card, and the bottom half to another card. Why reduce your output? I assume there are real reasons.
I have very vivid memories of sitting on my couch with a beer and a soldering iron modding 1200 PCBs with mod boards and mod wire
Only one beer?
well by the time i was done i had 6, and you could see the gradient of solder work getting progressively worse
Only noticeable with hindsight I'm sure ...
checking my work the next morning by grabbing random samples it was clear ... functional but we all know the shame of an ugly solder joint
it would be just my luck someone like you would take apart one of the later jobs on youtube
I wonder how big the market is for mod boards. There are plenty of obsolete parts still used for hobbyists and common repairs. Is there a database where you can search for an (obsolete) part and find the buy link for the replacement? It does not need to only offer mod boards, but all kind of items you could replace a given part with.
People have used them to get around security on game consoles.
L3 P3 Really good question. In the old days there used to be entire books of equivalent component numbers for ready look up. Not sure about these days.
Plenty, guitar effect pedals are a perfect example.
For example I recently saw this www.leobodnar.com/shop/index.php?main_page=product_info&cPath=125_127&products_id=324 board to replace an unobtanium prescaler IC in a HP/Agilent signal generator.
Useful if you have a need for exactly that IC (which apparently fails quite often).
NVRAM! nvram.weebly.com.
Can somebody help me? In which video does Dave unpack the complex board from the beginning and some others of the same type ?
you're in terrible pain. you convinced yourself not to use the word BODGE
We call them Bonus Boards
I like that
Absolutely FREE, if you call NOW before the next board revision!
Interesting video - and cool shirt!
Nice concepts
why is the no mask zone of the fiducial square and round on the other one? does it help for orientation? ( thought that having 3 fiducials was enough to avoid problems)
In the 80s a mate used to improve output stages on synthesizers by replacing the nasty factory OpAmps in TO99 metal cans with a daughter board with a higher spec OpAmp and some magic, including shielding (shielded signal path), and a little heater circuit because thermal instability was a problem. He used to make good beer money once word got around.
I don't understand how the pick-and-place machine uses the mod boards in production. Does the machine break them off the larger board you showed and then place them? Or, does someone have to break them off manually and then put the little mod boards into some kind of a magazine? Thanx
Someone has to break them and place them in custom trays. If you weer serious you would do this, but most likely easier to simply hand solder the part.
@@EEVblog Ok, thank you. This makes sense. Otherwise the pick-and-place machinery would have to be quite complex. I guess that's obvious
@@henryD9363 I was confused at first. When he was talking about putting that board into the P&P machine, he was talking about putting the components onto the mod board (populating the mod boards with components), not putting the mod boards onto a main board.
We hand place these after pick place and before reflow. Too much trouble to program and make trays!
Just a fancy name for a bodge.
New mailbag setup is working, looks good, color is a little off, lighting temperture?
In the defence industry, finding replacements for obsolete parts can be a real challenge. Especially for older systems where there's not enough documentation. Legacy platforms and systems are a real pain.
I can imagine: Remove good part, characterise, implement old part with new tech on same footprint, re-qualify part, install.
That why we had a full time engineer just devoted to that role
@@EEVblog Especially because there is a whole business model catering to defence industry that will try to sell you that shitty jellybean germanium transistor at ridiculous price because they bought out all the stock from the parts market.
@@EEVblogthere was one recent example I know of where an engineer was asked if a particular power resistor could be used to replace an obsolete one but there was only an assembly instruction for the equipment, no dimensions or anything. It was considered finding the platform that this equipment was fitted to and finding out that way but it really was not worth the engineer's time to do that. Shame really... the defence industry (at least where I live) is really behind the times in terms of obsolescence management and legacy management.
I did this job for a few years and it was a right royal pain in the neck. I had bosses expecting pin for pin replacements on tech which was completely obsolete. Gallium transistor type obsolete in some cases. With simple stuff like op-amps there was often a similar device but rarely in automotive grade (-40 to +125C temp range) never mind full military (-55C to +125C) and rarely in ceramic packaging (the ceramic package helps match the coefficients of expansion between the chip and everything else). Then try getting one to MIL-STD-883/B.
Will there be a video talking about the mod you made to the 121GW? I made a mod board for a Motorola D2 Evaluation kit a few decades ago. The board allowed me to plug a 6809 CPU in to the 6800 CPU socket on the main board.
5:00 Apparently Dave and I got something in common. We both enjoy Milf double stacking!
Reckon you can ever do a video on how mod chips on the old games consoles worked? Some interesting semi basic stuff going on there.
SMBT3904 if i am not mistaken that is that transistor snuber circuit
Good video.
at 16:00, isn't the component on the left of your mod board (marked D6 on the underneath board) blown up? It has a bubble on it...
Thoughout the video, you can see all the layers on the PCB, is it still financially more practical to make it wil that many layers over just having a single, thick board?
It would be nice to see what this mod board is replacing
Please share the video link on panelisation
It's really an "add board", because it can only add wires/components. But sometimes you want to remove traces, and switch where they go. What can you do? Cut traces and then "add board"?
Have fitted many of those to game consoles
Like when people hear that america spends 750 billion on defence. They assume its like buying weapons or something. What they miss, is that a large percentage of this is just maintenance. It cost alot to keep military equipment going. Spare parts in that 750 billion, is a massive chunk of this.
People always seem to assume, america is spending all there budget just on buying or building new weapons. When probably a massive chunk of there budget is just spare parts.
So its not surprising to hear about a lesser military having techs that keep older military gear going longer.
So in real world, america is spending a small percentage on rnd, and actually buying new weapons.
But people assume when they hear these massive numbers, america must be doing massive amounts of research, and developing weapons, when a large percentage of there budget is just like spare parts, and maintenance.
and $20k an hour to fly just an F-16. It's something nuts like $70k/hr for an F-22.
I needed a mod board to replace an obsolete SOP8 with a SOT 23-5.
My first problem was finding a board house that did castellations.
Then they would not get small enough, so I have grind one side on a grinder to
get the other side castellations. This was a couple years ago, but I ended up
going with OSHPark. It's a high side switch. Pic of it here: imgur.com/a/u41l9bp
Woah, that outro!
Whats a commun radius for the half-moon vias?
Are there industry standard PCB sizes?
Yes and no. There are some standards for some specific systems like VME, and the PC104 format (which I think is now obsolete), and for PC motherboards of course like ATX size etc. However for a lot of applications there is no standard. EG in the automotive industry I did not design any two boards the same size. Even boards doing the same job for different customers were different shapes often due to connectors. The only place I know of with standard sizes (sort of) is panel size for the PCB's to be etched on. One of the sizes is roughly A4 size and often the PCB design is fiddled with to get the maximum number of PCB's per panel. Basically it's one long session of jiggery pokery start to finish.
Interesting and timely. I want to do a board that is about that size. Its to replace an SMD crystal in an HC-49/S SMD package. I was wondering how I can get a board that is only 12x4mm made.
Same as any other. Just make sure you have it populated before it is depanelized. I.e., if your pcb manufacfurer and your assembly house are not the same company, be sure you order your pcb as complete panels!
Cool video. With our customers it's rare to see them making an extra board for a mod, most of the time it's just a bunch of bodge wires ;^)
Also Dave, how are you planning to roll the 121GW mod boards to those that already have the DMM?
I'm guessing the modboard is to make up for a supply deficiency (the part went out of production?), not a design flaw, so there should be no problem for existing units
He mentioned in another comment it is only for new builds and not for those already in customer's possession, as if you do the mod on your tool it will require recalibration on multiple circuits. And the mod is an upgrade, not something your tool necessarily needs.
No need for the mod board for existing customers.
What does SMB stand for?
To sum it up... posh bodge :)
Was it actually economical to pick and place a board like this? It doesn't seem like you needed them in quantity really so the setup costs alone seem like they would have been excessive per board.
When you are a company that does this stuff daily, it would be cheap and easy
@@EEVblog Ah sorry I wasn't very clear. I mean in this example with the board you were handling for most of the video, the one which only contains the clamping transistor pairs. I was curious how many of those you actually needed populated by pick and place and if that was economical. After all how many of those sheets did you ultimately have populated compared to the tooling and setup costs?
The board I showed was not pick and placed. I was just mentioning that it would actually be possible if required.
Link to the paneliziation video - ua-cam.com/video/VXE_dh38HjU/v-deo.html
TL431 FUNDAMENTALS FRIDAY!
I remember my first mod board. it was a simple PCB to upgrade my 8088 to a V20 with a RTC clock. Ah good times.
That must have been a while ago. I had forgotten about the V20.
Professional bodge.
Illegal console mod boards? Mate, you live in Australia.
Those things were ruled to be legal here due to consumer protection laws. XD
Then again, we DID sign the DMCA after that point, so who even knows anymore.
These kind of boards remind me of the kinds of things you need to make/buy to be able to use certain kinds of parts for hobbyist or experimental purposes.
It can be pretty difficult for many components to still find through hole DIP packages - especially for more complex parts such as say, a CPU or FPGA.
Sure the reasons aren't a huge surprise, since the pin count can quickly explode. (consider if you had a 4 gigabyte RAM chip with a full old-school parallel address bus - that's at least 8 data pins, a minimum of one power and ground pin, a read and write pin, probably a chip select pin, and 32 address lines - that's at least 44 pins, which strains against the limits of practicality for a DIP package, and of course is huge in such a package for good measure.)
So... To deal with BGA or even a typical QFP in a hobbyist, one-off or experimental context almost REQUIRES the use of mod boards to bring it to a more reasonable form factor..
Sure it depends on what, exactly you're doing, but more often than not, this is the only way to reasonably use such parts in that kind of context...
Boards that facilitate in the pirating of software are legal? Real nice.
@@xenonram Please, lookup the homebrew scene. There are people coding games and tools for systems like the PS3.
Bit of a bodge in removing that mod board Dave :-D
Another great video, thanks Dave.
I'm wondering if there's such thing, similar to the through hole matrix breadboard prototype type PCBs you solder to, but for surface mount.. I seem to be accumulating loads of surface mount things but.. not really sure what I'm doing with them!
There is a few options on ebay, but, for the most part seem to be outrageously priced.. ..speaking of which, digikey also has a vast stock of proto boards, i wasnt looking for surface mount in particular, but, they would probably be your best bet as they are a reputable source.
@@topherteardowns4679 thanks, I'll keep my eyes open then! I have various proto boards, the strip and matrix ones anyway. Perhaps I can figure out another way to use them with surface mount.. I trying to avoid buying a bunch of breakout boards and such for something I'll inevitably mess up 🤣 I bet I can repurpose small pieces of strip board or so and make little pieces like Dave or something ☺️
@@ollieb9875 yeah, I always buy cheap proto boards when I see them, just because they are cheap and can be used for a limitless number of projects -I even use smd chips on the standard .1 hole proto boards.. Sometimes its a pain in the ass, other times it is much much much more beneficial than either trying to find the niché adapter or making a board and spinning it in FR4 pcb. If I comr across the seller/order i recently got of the smd proto, I will reply here with the keywords to search
@@topherteardowns4679 I think I saw some on mouser.co.uk (being in the UK) SMT proto or breadboard, something like that, but never really looked properly.. I'm making some things for Christmas so will look tomorrow, but I may just do as you say and use what I have if they're too expensive ☺️ Cheers!
I use a BFH to modify outdated PCB’s.
When your panel is so floppy because of the many cutouts, why don't you leave some wider edges and spokes to make it easier to handle during assembly?
You could, especially if you had heavy parts. In this case it's not needed.
Sub assembly, I think I've heard it called that before.
I've been working on a handheld gaming machine using a SBC (Lattepanda), and I found that there's a ton of nice 2K LCD modules on aliexpress that come with this generic MIPI to HDMI driver board. Some chatter about people trying to design these boards on the forums, and on GitHub, but all abandoned. I was originally thinking of designing some sort of FFC to connect the HDMI from the driver board to the SBC (perhaps with a "repurposed" HDMI switch in between so I can still have an HDMI connector somewhere on the thing). I've never designed an FFC one, and they seem expensive. Do you think it might be possible to create a modboard to replace the connector instead, or am I going to destroy it when attempting to solder onto the HDMI connector pads? Maybe there's a better technique?
Do you need the processing power of the Latte Panda? The R Pi has some really nice touch screens available and they are really low power. Also what do you mean by FCC? Flat Conductor Cable? There are that I know of at least 12 uses of that acronym in the electronics industry. I'm presuming the LCD screens have MIPI interfaces? One of the reasons they might be so cheap is that HDMI to MIPI interfaces cost a fortune relatively speaking. IE the cheapest I know of is £50+. I have a Pi with one of these www.raspberrypi.org/blog/the-eagerly-awaited-raspberry-pi-display/ and it cost about £80 a while back. Not 2k but it works well.
@@gordonlawrence4749 I really need an x86 processor. The pi 3b+ is a brilliant board without a doubt but I'd really like to be able to run windows x86 apps. The 2 lane MIPI connector on the pi is also a real drag. It just can't push out as many pixels as HDMI, but what's the alternative if not these relatively expensive driver boards? It seems only proprietary drivers and driver boards exist in both the pi ecosystem and elsewhere when it comes to MIPI.
@@gordonlawrence4749 and yeah, I was talking about designing a flex connector like Dave was talking about in the video, but while they're great on space they seem to be an expensive pain in the ass.
You took 3 minutes to explain why they are done :) that was funny.
Because there are many reasons why they are done.
They are done to hack Consoles.. I mean.. uh.. replace obsolete parts
Could have gone dead bug style for this mod. Why go for the mod board approach? Cost perhaps?
Repeatability, and ease of assembly
Super!
whatever happened to your C5 Sinclair that you had
If you want some examples of what these are used for in the console space, other than the old piracy chips, this site has a good selection of the video quality upgrade kits, generally used to get a decent RGB signal out of old consoles that used composite/RF; www.oldskoolconsoles.com/shop-2
Not associated, just first link that showed up for me :)
I heard them referred to a 'kludge' boards before.
A great solution to do anything,great explanation of this please do not read this status thank you for information
5:57 Did you just blow all the components to and fro with the hotair rework tool? :D
The board crumbled when taking it off, it was a mess
pcb manuf have minimum board size requirements.
Do smt components have like glue on the bottom?
some larger parts can, small components simply sit and stay in the solder paste which is applied to a board before placing all the parts. the surface tension holds them ok. this kind of stuff is usually on machines and conveyors so they aren't moving far and people (generally) can bump them and stuff.
The assemble can apply glue if needed
the word you are looking for is "BODGE"
Can pcb's be laser cut or would it make a lot of smoke
Copper is reflective and highly thermally conductive, so it takes a huge amount of laser power to cut.
The fiberglass substrate probably could, though! I'll have to try that.
_Bodge Board_ ?
- Eddy
Guess leaving the copper on the board is cheaper than to try and recycle the copper later by precipitating the copper out of the etching solution.
Maybe, maybe not... The way PCB manufacturing was explained to me was you started with really thin copper then plated extra copper onto the parts that were going to be used, then masked that and etched away the unwanted parts. Excess copper fill would be a waste as it would need plating even if it was not used.
Obviously this doesn't apply to DIY jobs.
@@boristheengineer5160 I have never heard of PCB plating copper onto the board. I was under the impression the boards come with a laminated sheet of copper already glued on.
@@MyuFoxable I think they plate as part of the via plating process
@@MyuFoxable The laminate would have a reduced thickness of cu compared to the final PCB. To get through-plating the PCB would be drilled right at the beginning then would be treated somehow to make the insides of the holes conductive. The resist would be applied in reverse, exposing the places where copper was required. Then plating would thicken the tracks to the required thickness and coat the holes. It would still need a conventional etch at the end to remove the unwanted thin copper.
It stuck in my mind because it was almost the reverse of the classic etching process I'd always read about and used a bit for prototypes.
@@boristheengineer5160 It is making more sense now, particularly with the conductive holes example.
Your videos are awesome .. This one is no exception. However, it would be very kind of you to tell me what is that device in the background, on the left side of the screen, under the registration plate saying: "OUTATIME". The one with the keyboard on it ... The device keeps distracting my attention.
A kit from Intel to build an 8085 development system.