I just did some searching and it looks like you can replace the key switches with Cherry MX switches then 3d print a adapter to connect key cap to the cherry key. Thingiverse: Cherry MX to Datanetics DC-51 Keyboard Switch Adapter. Hope this helps for a future video and gets the keyboard back to full function. Keep this old keyboard going hopefully. Keep your head high Adrian and thanks for another great video.
Yes, that would be the best bet. It is Thing #5780203, and should be good enough in filament for keyboard purposes. Maybe JCM could make a keyswitch kit with all the key switches and adapters, so it would just be an exercise in soldering. Cheers!
Designer of that adapter kit here: I recommend you print in PETG over PLA and to try to adjust your settings for good inter layer adhesion. I had written a longer comment earlier but I suspect some auto moderator system ate it since I had put a link to my write up on Applefritter with more background info than the Thingiverse page. I have licensed the models under CC-BY-NC-SA, but if someone like Joe's Computer Museum or ReactiveMicro wants to make kits using them I am very much open to proposals.
Was about to suggest something along these lines, glad to see someone has already created a suitable mod. Would love to see a video with this upgrade done.
@@LouisCYUL YT only allows links for accounts with a very high rank. The three best ways to _reduce_ the rank are to reply to other people, make negative comments about leftist politicians, or talk about computer-related topics. Foul language doesn't reduce the rank nearly as much as those three factors. I've figured this out by reducing my rank to the borderline and then testing which words or actions get my post hidden. I don't know what terms are best for raising the rank, sorry. However, I do know that posting 20 comments in a row on the same video raises the rank a lot.
@@Mavendow posting 20 times in a row works, wow. I wonder if the author 'hearting' your comments would also boost it. stating that. if it does not look like a bot and does not inject urls all the time, it may improve. sadly we all don't know since the yt algo is fickle and always changing and people reporting comments may help or massively hinder your hidden metric
That’s a great original bodge to get the original L key working. I can imagine being in a place with no spare parts available and someone coming up with that repair. It worked for someone many years ago. Thank you for the video Adrian. Long time watcher first time poster.
I recall that the official service routine by 1980 was to r/r the whole mechanism as Datanetics turned into TKC and was absorbed by Apple. I have never seen a DC51 switch hacked like that before in my entire career, but by around 80 or 81 the DC51 switch was deemed obsolete, and replacements were no longer being manufactured.
The power light is actually one of the same keyswitches, except the stem was hit with a soldering iron to immobilize it, and the light bulb was placed under the cap. If you worked on the plastic a bit, you might be able to make it work as a keyswitch again. The reset switch has a modified spring, so it requires more force to push. Even so, a common measure to make it even harder to push was to put an O-ring around the key stem. That make it very difficult to depress with your pinky, but you could still use press it with enough determination.
You can actually split those keys in half. They are plastic-sonic-welded together, but a sharp knife will split the seam if done carefully. You can then disassemble the guts and clean the contacts, and super-glue the key back together. It’s very tricky to do and even after doing many of them, I am only successfully about 80% of the time. Also, if you were to take the key apart, you will see that the contacts are virtually sealed in between 2 layers of plastic film, so spraying đeoxit from the outside does not penetrate to where the contacts are located. Basically these keys are notoriously a PITA to service. I’ve had pretty good luck resurrecting non-functioning keys with a ultrasonic bath of isopropyl alcohol (done safely with a beaker!).
I've done lots of them as well, and 80% is amazing - I'm lucky to get half of them working correctly. About 3/4 work to a limited extent, but not reliably enough to put into a machine I'd use.
I have also worked on a great number of those DC51 switches. Are you on any forums, as I would like to communicate with you. If you want to reply with your forum ID on say, Fritter, or your email, we can have an interesting chat.
@@MistahMatzah Aye, my success rate is roughly 50 to 60%, although I do have a source for good switches that comes in now and then. I have a bag of known good spares, but they are reserved for a B&H Datanetics machine and a few for my '77 machine that have split open (on their own). As with my reply above, if you want to chat about this, reply with Fritter/AtariAge forum ID or an email that you can use as a tossaway and we can discuss our methods.
Thanks for all the great videos! Just for everyone's benefit: --- WHEN IN DOUBT, PIN IT OUT! --- Those cables for the keyboard can be crimped in different orientations. Therefore, it's possible to have what seems like a compatible pin-out but maybe it's not. When building my Apple-1 replica and case, I had several similar cables I took from some old HP equipment, and I found that some of them were crimped out in different directions. The cable and red strip were flipped around on some, and flipped inversely on others. The result is that I took the time to tone-out and test the connections with a multi-meter and made sure I wasn't plugging something in reversed. I have actually destroyed some chips on my Apple II by doing this, because it's so easy to do, and although I only had to replace one 7400-series IC, it still sucks to blow out these old chips. Thankfully the controller chip in my Apple-II keyboard controller board wasn't damaged, although I think I remember that another 7400-series chip was.
11:42 “mask programmable” means it is programmed during manufacturing of the die, the IC itself. The mask is a lithography mask (or rather a set probably) that allows the traces to be etched that comfigure the correct wiring to the logic in the IC.
As someone who was fortunate to grow up with a color monitor for my Apple IIc there’s so much about the Apple II that gets lost with monochrome displays. I realize that most people are more nostalgic for them as that’s the way they experienced Apple software back in the day but I can’t help but feel sad that one of the big selling points of the design was how it could do color with minimal circuitry. Part of the big reason the Apple Logo featured a rainbow for the Apple II in the first place.
As you now have a programmable microcontroller in there, you could ask Joe if he can filter at least the worst of the multiple key presses in software. As you have no repeat function on the keys without pressing the repeat key, that could be used to switch the filter on and off.
I would think some or all of those double key presses could be eliminated by better debounce logic in the encoder IC. I’d talk to Joe about that. Or possible solder a 100 pF cap or something across the contacts of the problematic keys.
Wow... bummer. I came to watch before starting my own repair and now I'm not very optimistic. I have a mix of dead and double-striking keys. I thought it was just going to be a deoxit job, but it looks like not. Thanks for documenting this so carefully. It saved me a bunch of time and frustration.
For repeating keys, did you notice there is a debounce variable capacitor to adjust that? Pin 17 in the datasheet. (Is that used on Joe's replacement board?)
With all the mechanical keyboard projects being developed for other computers that suffer from crap keyboards, I'd have thought by now that someone would have taken this project on to create a standardised keyboard for these comptuers too, given they already have the basis for them given a lot of them are switch-based already, and now with that controller PCB being available, it opens the possibility of the new keyboards being an actual thing... :)
I remember my first time using an Apple ][, the whole having to hit reset to do anything on power up blew my mind. Every computer i had used prior had a power on reset function.
These crap quality key switches are what made after market keyboard vendors so successful in those times. A friend of mine had keyboard problems with his Apple and they wanted way too much money to replace it so he went with one of those after market designs. That eliminated his keyboard problems permanently.
The big differences with the plus model were the revision 7 motherboard which no longer supported 4K DRAM and removed that capability along with the cost of the memory select jumpers, the switch from the original PMOS 2513 character generator to an NMOS ROM with a standard EPROM pinout and control polarity to enable international character sets or lowercase, the switch to the 2-piece keyboard again for international capability or the option to introduce lowercase, and finally standardizing on the autostart ROM with Applesoft. Random fact: if you load integer basic into the language card, the Programmer's Aid #1 was included in the ROM image included and contained a virtual 16 bit processor written by Woz called SWEET16.
The early ][+ machine differed only in the following: AppleSoft BASIC was standard; 16K min RAM; soldered in RAM jumper blocks; different badge; green part labell with different model number. Otherwise, they had an electrically identical Rev 4 mainboard. The R7 was early 81 and beyond IIRC, perhaps late 1980. In '79, it was still Rev 4 with a raised lamp Datanetics.
@@orbitalgolem91 The color killer was improved a bit on the rev 7 board, but it's present on all the revisions except rev 0 and it worked perfectly well on the rev 1. I had a rev 1 in 1978 with a 13" Sony Trinitron for a monitor.
Awesome attempt to fix the keyboard. It’s a shame that there aren’t aftermarket switches you could use or someone who had a bad keyboard with some working switches you could use.
Thanks for another excellent video, a frustrating outcome for you. Unhappily for such a notoriously unreliable key mechanism I guess if there was a good replacement it would have been found by now. Still, I'm surprised there isn't a 'near enough is good enough' option even if that would require replacing every key.
I recall trying to find some of those 16-pin DIP to ribbon cable adapters a year or two ago, and could only find 14-pin versions. But if you're really careful you may be able to pry apart the old ones from the bad ribbon cable without damaging the latch-y bit. As for the bad keys, I notice they seem to have a + stem, so it would be great if the pins were in the same orientation as modern mechanical keys and you could just replace the whole set of them, but I bet they aren't because everyone would have been doing that already.
Another commenter says you can put Cherry MX (compatible) switches in there and 3D print a stem adapter for the keys, so it’s probably just more involved than most people are willing to do :)
Oh no the DC 51s😧😧 Those switches are horrible. The plastic piece inside either breaks and causes a short or it wears into the mylar contact pad and breaks it. Glad Apple went to Alps and SMK for the II e. Good luck brother👍👍
My friend has been playing with designing and 3D printing her own key switches, and she's made a surprisingly good progress considering she's only got a cheap FDM printer. She's successfully made a sliding mechanism that has a nice detent, although it doesn't have any contacts yet. I'm not suggesting making a whole key switch from scratch, but perhaps you could find a key switch that has a low enough profile that would allow you to 3D print a bracket to adapt it to fit into the holes on that keyboard, and also an adapter to fit the key caps to the stems.
>I'm not suggesting making a whole key switch from scratch Why not? It was my first thought when I watched this video "why not 3d print freakin' key?" Resin printers make high precision prints, are they still not enough for the key?
I spent a lot of time playing Drol, but I never managed to finish the third level. I learned a lot, and had a lot of fun with my Apple ][+ (clone) systems, in the '82 to '85 timeframe. I had it tricked out with every slot occupied: integer BASIC card, serial card, Hayes Micromodem card, 80-column card, realtime clock/calendar card, Z80 CP/M card, disk controller card, EPROM programmer card. I wrote a high-resolution Game of Life program in assembly language, which ran pretty fast. I regret that I gave it away to my nieces as a Christmas present.
Why not take a couple of general keyboard switches which you can take apart and make them fit using a 3d printed key stamps? Should be a relatively simple way to make the keyboard work like new.
Bought a II+ a few years back and the only sticking point is the sticky or non-working keys becoming an issue again. Silas Werner made some great games like ABM and Robotwar for it, and Apple Panic is an amazing time waster. Some games like Sneakers are really hard games. I got interested in it because I did a high school course as work experience in Grade 9 in 1979 at an Apple computer dealer in Sechelt, British Columbia. I think he was the second one after the Byte Shop in Vancouver. Our computer lab used PETs until the Apple 2 plus came around but I ended up getting a PET for $200 from the district, but I ended up going to a Commodore 64 to keep some compatibility.
It’s unfortunate that so many keys have issues. If it were just the arrow keys, the Escape key, and the Return key, you’d have Control+key equivalents to use as a backup.
Never touch lead metal or solder without hand protection. Lead and its salts can enter the body through the pores of the skin. Set an example for young enthusiasts of vintage electronics and computing to observe prescient precautions when enjoying the hobby.
Drol was such a strange game. I played it quite a bit on my C64. Brøderbund made so many good games. I love the key caps on that keyboard. Hopefully someone will make a modern switch that fits both the circuit board and key caps.
28:22 - OK, lets go backward 46 years, with maybe not so much keyboards on stock. I think we should salute to dodgy repair man who tried to do this. Maybe machine was not used so often so one key could work like this. If it works, it works! You just examined repair job from 45 years ago.
ehm, wait a minute, the keyboard encoder is a programable microcontroller, it should be possible to filter out the double presses in code. Specially considering this is a expected problem in those old keyboards im suprised this is not already in.
Oooh, I'll have to keep an eye on Joe - I have a dead Mac Plus keyboard that needs a replacement. Somehow I lost my original keyboard and got this one on eBay but it was dead and I'm betting it was an incorrect cable used at some point. (Good grief Apple, why on earth did they use a cable that could be mistaken for a handset cable but be fatally incompatible!) I've toyed with the idea of using a Pi Pico to replace it but never really did any work toward that. I did find a listing of the code for the original controller, which was a mask programmed version of the Intel 8748 microcontroller. Found some on ebay, but would need a programmer and an assembler. A modern replacement would be awesome tho!
So for me the question would be which is better a machine that is as close to factory as possible or one that works well. I'd say stick with the 2 plus keyboard and if the esthetic difference the power light being flush rather than raised it should be possible to bodge together a way to move the taller power light to the other keyboard. Machines from this era always had a number of mix and match components. My first computer was a Tandy 16K machine, but by the time I retired it it had 64K, I don't remember how and an external hard drive that was connected through the cartridge slot using an adapter from a company out of Syracuse, NY. My next machine was an IBM Portable. IBM had no hard drive available so I found a half height Tandon, it would fit without its face place, I soon realized if I cut the sides off the Faceplate it would fit so I remember cutting them off with an exacto knife. At least to my way of thinking creative ways of changing them to make them keep working is equally a part of what they were and are. Just my two cents.
I've bought 2 from Joe for my //e and //c, they works great! The new replacemnt consume much less power than the original, already changed my //e and //e with WDC65c02, it consume incredible low power, means CPU stay cold all the time.
Adrian, you probably found quite a number of posts from me in your research. :) This video made me very sad though, as you can indeed repair the switches; and still source them, albeit not inexpensively.
I had a bad flat cable on my Apple //e - floppy cables. When I opened the crimping bit I saw corrosion on the bits which penetrate the cable. I just cut 1cm and re-crimped them and it's been working since. It was such a pain to identify, the floppies were working intermittently!!
I don't suppose any modern mechanisms can be adapted to fit the board and keycaps? I mean, those keycaps looks great, so I think they deserve the effort :)
I'm betting the fact that the keyboard converts keypresses to ASCII characters is a holdover from the terminal days. The earliest microcomputer displays and keyboards were essentially dumb terminals attached internally to their host computers using the same signaling technologies that mainframes and minis were using. The Heathkit H89, a very Fallout looking all-in-one computer from the late 70s, had a toggle key on the keyboard labelled 'offline.' When it was down, the monitor and keyboard were physically disconnected from the internal CPU, and their IO was redirected to the serial port on the back of the machine. This allowed the H89 to switch between dumb terminal and computer mode on the fly. I've always wondered if anyone actually used that functionality.
If you want a plastic safe contact cleaner, I highly recommend BW-100! It's nontoxic, non-flammable, quick to dry, and works extremely well. Only thing is that it's only available on Amazon and more expensive than most contact cleaners, plus the only available can size is rather small, so definitely get 2 or 3. It worked wonders on one of my parts keyboards. It's pretty much the only option for delicate electronics.
In the UK, we don't have JB Weld... our dominant 2-part epoxy is "Araldite"... I've often wondered, if you did a big in-depth chemical analysis, would you come out the other side and say "Yup! They're exactly... EXACTLY the same stuff!".... sorry.... back to the Apple ][ ... I love how control-G is still labelled as "BELL" although none of the other keys have their ASCII CONTROL name on them... Trying to work out what "bell" meant got me on the road, as a kid, to working out how the control key worked - I used to love to show off the fact that I could press CONTROL-[ and it would do the same thing as pressing Escape or Control-M was Enter/Return....... the simple joys of childhood.
These old key switch models that use basically hybrid membrane mechanical switches should be thrown in the bin where they belong. The only real key switch they should be replaced with, is a mechanical spring-snap switch like what is produced in modern mechanical keyboards. Trying to cut costs on keyboard designs in the late 70s, early 80s made these terrible design choices come to fruition. I'd take a rubber dome membrane keyboard from the 1990s with carbon contacts, over one of these abominations of materials engineering.
Modern rubber dome keyboards are pretty okay. They are plenty durable and incredibly cheap. Mechanical boards feel better of course, but the rubber domes work just fine.
One of the biggest issues home microcomputer manufacturers had to solve with early micros was that certain components like good keyboards, memory, disk storage, etc all were very expensive and at the time there was a built-in market for home micros as there is today. If you were going to sell a home micro to a family or individual that wasn’t sure they really needed a computer in their lives yet or was on a very tight budget then you needed to get the price as far down as you could while still having a usable computer. They manage this in several ways. First, they cut down on the amount of built-in memory, at least for base models. They’d get around the limited memory issue by offering an option plug-in RAM cartridge or RAM board to expand the memory or they include unpopulated RAM sockets for optional additional RAM chips. With graphics, they cut cost with offering either monochrome-only output or limited colors and using poor quality RF TV output as standard so budget users didn’t have to buy a stand-alone computer monitor. With the keyboards, they went with cheaper designs like these hybrid keyboards, chicklet keyboards, membrane keyboards, etc over better quality but much more expansive proper mechanical keyboards. The use of membrane keyboard party explains how Sinclair got the Z80 & 81 (Z81 was sold as the Timex-Sinclair 1000 in U.S.) under £100 ($100 for the TS-1000). The Atari 400 did the same with its membrane keyboard choice. Another common choice in early microcomputer keyboard design was to only include uppercase letters in the built-in ASCI character set. The Apple II and II+ lacked lower case characters built-in with IIe being the first to properly support both upper and lower-case characters. The choice to use audio cassettes for data storage over then expensive floppy disks in the late 70’s and early 80’s (and longer in the UK) was about cost cutting. Yes, some of the early design choices dictated by the need to cut costs seem stupid today with our decent rubber dome keyboards and cheap RAM and such but back then the manufacturers had to make trade-offs. Maybe they could have picked better trade-offs in some areas but sometimes early home computer users just had to learn to accept that until the costs of certain complements come down, they would have to work with whatever the manufacturers could provide the buyer at the price they were willing to pay. Some did better then others at this balancing act but every home micro was compromised in some way. The Apple Lisa didn’t cut corners the way the later Apple Macintosh 128k did but sold for $10,0000 ($30,000 today) in ‘83 and was a flop while the Mac 128k (1984) sold for $2500 ($6000 today) and was much more successful.
They’re not all great. I picked up a generic dome PS/2 keyboard from CompUSA in the mid 2000s and I’ve managed to wear out the right shift. The dome isn’t springy anymore so pressing the key just lodges it in the stem guides at an angle. This is a pretty cheap keyboard, so it’s not unexpected, but I think we’ll see more of those kinds of failures as low-cost 90s and 2000s keyboard get to be 30+ years old.
Can I be honest.. as a serious Apple II collector.. I actually hate the single PCB A2 keyboards. They look great, but even when they're working they feel like you're typing on a Coffee Crisp. And of course 40+ years later, they're often not. I have found the alcohol + 100 keypresses trick works for a while.. but they often go back to trouble. The later II+ keyboards, before the foil tab (yuck), are the best.
It depended on what slot the floppy disk controller card was in. Slot #6 was the standard. The monitor's 6^P command re-directed the system's output to whatever card was in slot #6. It was a way to give control to the disk ][ card, which would boot the system if necessary, and start watching for disk I/O commands in the output stream. It's pretty amazing how they shoehorned that functionality into the system.
@@williamgraham2468 Oh I understand the logic behind it, I am a child of the 80s after all. Just that to a novice user it could be confusing. And I am not just bashing the Apple ][, most micros of the era were horribly designed in regard to the user experience. Disk commands on the c64 are also dumb and counterintuitive. Like destroying your basic program if you wanted to peek at your disk's content.
I've been fooled before by a completely non-working keyboard (except for the RESET key) on an Apple ///. I thought the encoder must be bad, but it was in fact the power supply - the encoder needed the negative -12V voltage, and it was missing. Worked fine the moment I fixed the PSU. If the encoder is completely bad, first check the negative supply voltage :)
00:04:38 I have found that a rigid adhesive is almost never the right call. Imagine a cookie sheet covered with a 1 inch thick coating of burned to carbon caramel. If you tried to lift the mess up out of the cookie sheet, It would take 8 million pound of force. However if you twisted each end of the cookie sheet even slightly, about 72 trillion tons of sheer force is generated and the mess pops out as a big chunk. This is why ice cube trays work. Ice is a great glue until sheer is introduced. Since the part you show is subject to flexing, there is the issue of sheer. In these situations, a flexible adhesive is best. Better yet is a Vulcanizing sealant used in a manner inconsistent with labeling. (as a glue) RTV sealant is absolutely wicked to remove off of anything. A part like that would break if you tried to pry it off after RTV, but you could remove it by sliding a razor knife between the parts. Not only that, its Vulcanizing so you don't have to remove the old RTV to re-glue. Like retreading a tire the stuff will fuse again with itself using a a bit of new sealant between them. RTV is different than silicone sealant. There are wild variations among RTV. Like grey RTV is generally more brittle and not a good thing for misusing as glue. Black RTV is amazingly stretchy. You want the stuff without the vinegar smell in this application. Permatex # 7651939 almost has a nice smell if you like a good new car interior off gassing. Leave a good bit hanging out of the applicator in storage. The product will slowly cure down the tip after 6 months of not use. This can usually be removed repeatedly, allowing the whole can to be enjoyed. Discard first quarter size glob from the tube and don't use the very very last bit out of the can either. (it will start coming out excruciatingly slow at the end, but will seemingly do this forever)
That connector from the encoder PCB to the keyboard is a common failure point. The sweeps on the sockets corrode and break off. I have not found any modern replacement that's anywhere close.
I (kinda) recently bought those connectors. I've gone over all sites I could think of, and couldn't find where I ordered them from. I remember it was Ali Express, but I can't find it in my orders history.
I added a reply to the actual place I bought it, but it appears that putting a link will get the reply erased. They are available, new, if you search the correct site for the name "DIP flat cable plug".
There was a difference between the ][ and ][ Plus motherboards - the Plus boards had a "color killer" circuit enabled in text mode, eliminating color fringing around characters that was present on older boards.
I can’t believe there wasn’t a class action lawsuit for Apple intentionally destroying keyboards if you tried to use them without their “official” cable. Can you imagine if they tried something like that nowadays?
I disliked the original keyboard for a couple of reasons, though I only had my Apple II for about 3 years. That raised power light got _hot_ and was easy to accidentally roll the heel of your hand into and get an uncomfortable "sear". The lowered one was relatively safe. And if you did not have the "Ctrl-Reset" modification, as mentioned it was too easy to accidentally slip and hit "Reset" at inopportune times. It was common practice to pop loose the lower half of a clamshell cassette box and lay the corner over (around) the "Reset" key so that you had to actually move the box to depress the key.
I wonder if you could make some sort of 3D print that would take the space of those long switches so you could replace them with say cherry switches. Recycle legs from components you snip on another project. Probably would be very involved but needed eventually.
@@JeffTiberend Absolutely. I was just thinking to replace the part that is broken. PCB works fine. So making cherry switches the form factor of those switches is probably the most original fix possible.
Suppose that tape was to prevent grounding pins against the nearby metal frame? Huh, wow, I'd put that bodged key in a display-case! XD What a creative way to fix a key. Somebody should print adaptors to mount these key-caps on different switches. With a shorter switch it'd be possible to have it look stock, or nearly so depending oh heights. Maybe a mounting frame to hold the switches in place as an alternate to the screws could be printed too?
anything digital that requires a negative voltage like a DRAM, or some very old NMOS logic devices will be damaged NOT ONLY if a bias voltage is missing, but also if the voltages come up in the wrong order. Many old devices sized the filter caps to ensure startup in the correct order, some better commercial computers like min-computers form DEC actually had circuitry interlocks to grantee correct startup of power supply voltages
Awesome channel have same Apple II same keyboard same issues. I have three keys not working Y,2, and 4 and some double type keys. I was going to buy that encoder you showed but think that may not fix my keys because every other key works correctly(IE they are not ALL out) I have two extra new keys switches may buy a few more. But to change them I have to know how to solder right? My double entry keys should I buy new key switches for those too? I am guessing, yes... anyways really enjoy your channel learning a bit about chips and how they work on that board cool!
I feel like this is one of those cases where you have to choose between "make it work" and "keep it original", and the "make it work" option would require a modern replacement of the keyboard pcb with one made brand new using off-the-shelf switches. But "keep it original" that you seem to have gone with is also an option, it just won't be working very well as a keyboard.
Holy cow! Looking at that bodged key, i am both inspired and disgusted. Somebody did amazing work to get a switch that works, but on the other hand, just replace the switch!
Too bad there aren't replacement switches. I'm thinking there may be, but would require quite a bit of modifications to the PCB as the pins may not fully line up. It would be interesting to see if anyone starts a side-project on restoration of these keyboards, even if the onboard chips need to be transferred to the new PCB and replacement key switches.
You know not a bad idea -- also though, since the microcontroller is laos aftermarket, it could theoretically be programmed to ignore such quick keypresses -- faster than a human might push them
I just did some searching and it looks like you can replace the key switches with Cherry MX switches then 3d print a adapter to connect key cap to the cherry key. Thingiverse: Cherry MX to Datanetics DC-51 Keyboard Switch Adapter. Hope this helps for a future video and gets the keyboard back to full function. Keep this old keyboard going hopefully. Keep your head high Adrian and thanks for another great video.
Yes, that would be the best bet. It is Thing #5780203, and should be good enough in filament for keyboard purposes. Maybe JCM could make a keyswitch kit with all the key switches and adapters, so it would just be an exercise in soldering. Cheers!
Designer of that adapter kit here: I recommend you print in PETG over PLA and to try to adjust your settings for good inter layer adhesion.
I had written a longer comment earlier but I suspect some auto moderator system ate it since I had put a link to my write up on Applefritter with more background info than the Thingiverse page.
I have licensed the models under CC-BY-NC-SA, but if someone like Joe's Computer Museum or ReactiveMicro wants to make kits using them I am very much open to proposals.
Was about to suggest something along these lines, glad to see someone has already created a suitable mod. Would love to see a video with this upgrade done.
@@LouisCYUL YT only allows links for accounts with a very high rank. The three best ways to _reduce_ the rank are to reply to other people, make negative comments about leftist politicians, or talk about computer-related topics. Foul language doesn't reduce the rank nearly as much as those three factors. I've figured this out by reducing my rank to the borderline and then testing which words or actions get my post hidden. I don't know what terms are best for raising the rank, sorry. However, I do know that posting 20 comments in a row on the same video raises the rank a lot.
@@Mavendow posting 20 times in a row works, wow. I wonder if the author 'hearting' your comments would also boost it. stating that. if it does not look like a bot and does not inject urls all the time, it may improve. sadly we all don't know since the yt algo is fickle and always changing and people reporting comments may help or massively hinder your hidden metric
That’s a great original bodge to get the original L key working. I can imagine being in a place with no spare parts available and someone coming up with that repair. It worked for someone many years ago.
Thank you for the video Adrian. Long time watcher first time poster.
I recall that the official service routine by 1980 was to r/r the whole mechanism as Datanetics turned into TKC and was absorbed by Apple. I have never seen a DC51 switch hacked like that before in my entire career, but by around 80 or 81 the DC51 switch was deemed obsolete, and replacements were no longer being manufactured.
The power light is actually one of the same keyswitches, except the stem was hit with a soldering iron to immobilize it, and the light bulb was placed under the cap. If you worked on the plastic a bit, you might be able to make it work as a keyswitch again. The reset switch has a modified spring, so it requires more force to push. Even so, a common measure to make it even harder to push was to put an O-ring around the key stem. That make it very difficult to depress with your pinky, but you could still use press it with enough determination.
You can actually split those keys in half. They are plastic-sonic-welded together, but a sharp knife will split the seam if done carefully. You can then disassemble the guts and clean the contacts, and super-glue the key back together. It’s very tricky to do and even after doing many of them, I am only successfully about 80% of the time.
Also, if you were to take the key apart, you will see that the contacts are virtually sealed in between 2 layers of plastic film, so spraying đeoxit from the outside does not penetrate to where the contacts are located.
Basically these keys are notoriously a PITA to service. I’ve had pretty good luck resurrecting non-functioning keys with a ultrasonic bath of isopropyl alcohol (done safely with a beaker!).
I've done lots of them as well, and 80% is amazing - I'm lucky to get half of them working correctly. About 3/4 work to a limited extent, but not reliably enough to put into a machine I'd use.
I have also worked on a great number of those DC51 switches. Are you on any forums, as I would like to communicate with you. If you want to reply with your forum ID on say, Fritter, or your email, we can have an interesting chat.
@@MistahMatzah Aye, my success rate is roughly 50 to 60%, although I do have a source for good switches that comes in now and then. I have a bag of known good spares, but they are reserved for a B&H Datanetics machine and a few for my '77 machine that have split open (on their own). As with my reply above, if you want to chat about this, reply with Fritter/AtariAge forum ID or an email that you can use as a tossaway and we can discuss our methods.
Wonder how BW-100 compares, seeing as it's plastic safe.
Thanks for all the great videos! Just for everyone's benefit: --- WHEN IN DOUBT, PIN IT OUT! --- Those cables for the keyboard can be crimped in different orientations. Therefore, it's possible to have what seems like a compatible pin-out but maybe it's not. When building my Apple-1 replica and case, I had several similar cables I took from some old HP equipment, and I found that some of them were crimped out in different directions. The cable and red strip were flipped around on some, and flipped inversely on others. The result is that I took the time to tone-out and test the connections with a multi-meter and made sure I wasn't plugging something in reversed. I have actually destroyed some chips on my Apple II by doing this, because it's so easy to do, and although I only had to replace one 7400-series IC, it still sucks to blow out these old chips. Thankfully the controller chip in my Apple-II keyboard controller board wasn't damaged, although I think I remember that another 7400-series chip was.
I can, in theory, add an auto-repeat function to the encoder so no-one ever needs the REPT key again. ;)
It would be a really good source of an extra key switch for people struggling with dead switches like on this keyboard.
11:42 “mask programmable” means it is programmed during manufacturing of the die, the IC itself. The mask is a lithography mask (or rather a set probably) that allows the traces to be etched that comfigure the correct wiring to the logic in the IC.
I came here to say precisely the same thing. There are a few masked roms on this planet which have my name in them. They are not reprogrammable ;-)
As someone who was fortunate to grow up with a color monitor for my Apple IIc there’s so much about the Apple II that gets lost with monochrome displays. I realize that most people are more nostalgic for them as that’s the way they experienced Apple software back in the day but I can’t help but feel sad that one of the big selling points of the design was how it could do color with minimal circuitry. Part of the big reason the Apple Logo featured a rainbow for the Apple II in the first place.
As you now have a programmable microcontroller in there, you could ask Joe if he can filter at least the worst of the multiple key presses in software. As you have no repeat function on the keys without pressing the repeat key, that could be used to switch the filter on and off.
I would think some or all of those double key presses could be eliminated by better debounce logic in the encoder IC. I’d talk to Joe about that. Or possible solder a 100 pF cap or something across the contacts of the problematic keys.
Seems more than likely true. Was thinking the same thing.
Yes, that should be possible. I had the same thought.
Wow... bummer. I came to watch before starting my own repair and now I'm not very optimistic. I have a mix of dead and double-striking keys. I thought it was just going to be a deoxit job, but it looks like not. Thanks for documenting this so carefully. It saved me a bunch of time and frustration.
It's a beautiful Apple II setup! So great Joe creates things like this!
For repeating keys, did you notice there is a debounce variable capacitor to adjust that? Pin 17 in the datasheet. (Is that used on Joe's replacement board?)
With all the mechanical keyboard projects being developed for other computers that suffer from crap keyboards, I'd have thought by now that someone would have taken this project on to create a standardised keyboard for these comptuers too, given they already have the basis for them given a lot of them are switch-based already, and now with that controller PCB being available, it opens the possibility of the new keyboards being an actual thing... :)
Ah, Drol brings back memories. I used to play that on the Franklin (Apple knock-offs) computers we had back in my high-school 39 years ago.
I remember my first time using an Apple ][, the whole having to hit reset to do anything on power up blew my mind. Every computer i had used prior had a power on reset function.
These crap quality key switches are what made after market keyboard vendors so successful in those times. A friend of mine had keyboard problems with his Apple and they wanted way too much money to replace it so he went with one of those after market designs. That eliminated his keyboard problems permanently.
The big differences with the plus model were the revision 7 motherboard which no longer supported 4K DRAM and removed that capability along with the cost of the memory select jumpers, the switch from the original PMOS 2513 character generator to an NMOS ROM with a standard EPROM pinout and control polarity to enable international character sets or lowercase, the switch to the 2-piece keyboard again for international capability or the option to introduce lowercase, and finally standardizing on the autostart ROM with Applesoft. Random fact: if you load integer basic into the language card, the Programmer's Aid #1 was included in the ROM image included and contained a virtual 16 bit processor written by Woz called SWEET16.
The early ][+ machine differed only in the following: AppleSoft BASIC was standard; 16K min RAM; soldered in RAM jumper blocks; different badge; green part labell with different model number. Otherwise, they had an electrically identical Rev 4 mainboard. The R7 was early 81 and beyond IIRC, perhaps late 1980. In '79, it was still Rev 4 with a raised lamp Datanetics.
Color killer circuit also present on ][ Plus motherboards, enabled in text mode eliminating color fringing around characters.
@@orbitalgolem91 The color killer was improved a bit on the rev 7 board, but it's present on all the revisions except rev 0 and it worked perfectly well on the rev 1. I had a rev 1 in 1978 with a 13" Sony Trinitron for a monitor.
@@Peter_S_ Ah, yours pre-dated my ][ Plus in Dec '82. Hoping you still have yours, mine still powers up after over 40 years. Remarkable.
@@orbitalgolem91 Sadly, my father got it 'repaired' around 1982 and they did a motherboard swap with a rev 7, and that machine is long gone.
Awesome attempt to fix the keyboard. It’s a shame that there aren’t aftermarket switches you could use or someone who had a bad keyboard with some working switches you could use.
Thanks for another excellent video, a frustrating outcome for you.
Unhappily for such a notoriously unreliable key mechanism I guess if there was a good replacement it would have been found by now. Still, I'm surprised there isn't a 'near enough is good enough' option even if that would require replacing every key.
I *just* watched your first video on this Apple II, so it's nice to have the conclusion I was waiting for! Great work!
I recall trying to find some of those 16-pin DIP to ribbon cable adapters a year or two ago, and could only find 14-pin versions. But if you're really careful you may be able to pry apart the old ones from the bad ribbon cable without damaging the latch-y bit.
As for the bad keys, I notice they seem to have a + stem, so it would be great if the pins were in the same orientation as modern mechanical keys and you could just replace the whole set of them, but I bet they aren't because everyone would have been doing that already.
Another commenter says you can put Cherry MX (compatible) switches in there and 3D print a stem adapter for the keys, so it’s probably just more involved than most people are willing to do :)
Drol is one of my favorite Apple II games. :) Nice choice, Adrian.
Oh no the DC 51s😧😧 Those switches are horrible. The plastic piece inside either breaks and causes a short or it wears into the mylar contact pad and breaks it. Glad Apple went to Alps and SMK for the II e. Good luck brother👍👍
My friend has been playing with designing and 3D printing her own key switches, and she's made a surprisingly good progress considering she's only got a cheap FDM printer. She's successfully made a sliding mechanism that has a nice detent, although it doesn't have any contacts yet.
I'm not suggesting making a whole key switch from scratch, but perhaps you could find a key switch that has a low enough profile that would allow you to 3D print a bracket to adapt it to fit into the holes on that keyboard, and also an adapter to fit the key caps to the stems.
>I'm not suggesting making a whole key switch from scratch
Why not? It was my first thought when I watched this video "why not 3d print freakin' key?" Resin printers make high precision prints, are they still not enough for the key?
I spent a lot of time playing Drol, but I never managed to finish the third level. I learned a lot, and had a lot of fun with my Apple ][+ (clone) systems, in the '82 to '85 timeframe. I had it tricked out with every slot occupied: integer BASIC card, serial card, Hayes Micromodem card, 80-column card, realtime clock/calendar card, Z80 CP/M card, disk controller card, EPROM programmer card. I wrote a high-resolution Game of Life program in assembly language, which ran pretty fast. I regret that I gave it away to my nieces as a Christmas present.
Why not take a couple of general keyboard switches which you can take apart and make them fit using a 3d printed key stamps?
Should be a relatively simple way to make the keyboard work like new.
Bought a II+ a few years back and the only sticking point is the sticky or non-working keys becoming an issue again.
Silas Werner made some great games like ABM and Robotwar for it, and Apple Panic is an amazing time waster.
Some games like Sneakers are really hard games.
I got interested in it because I did a high school course as work experience in Grade 9 in 1979 at an Apple computer dealer in Sechelt, British Columbia. I think he was the second one after the Byte Shop in Vancouver.
Our computer lab used PETs until the Apple 2 plus came around but I ended up getting a PET for $200 from the district, but I ended up going to a Commodore 64 to keep some compatibility.
I think for that bodge'd L key switch, you could probably replace the wire with a thinner gauge one and get it working again.
that moniter looks fantastic with that nice apple!!
It’s unfortunate that so many keys have issues. If it were just the arrow keys, the Escape key, and the Return key, you’d have Control+key equivalents to use as a backup.
DIP ribbon cable connectors are still available from Digi-Key, Jameco, and Mouser. Amphenol, TE/AMP, and Omron are among the manufacturers.
Never touch lead metal or solder without hand protection. Lead and its salts can enter the body through the pores of the skin. Set an example for young enthusiasts of vintage electronics and computing to observe prescient precautions when enjoying the hobby.
Drol was such a strange game. I played it quite a bit on my C64. Brøderbund made so many good games.
I love the key caps on that keyboard. Hopefully someone will make a modern switch that fits both the circuit board and key caps.
28:22 - OK, lets go backward 46 years, with maybe not so much keyboards on stock. I think we should salute to dodgy repair man who tried to do this. Maybe machine was not used so often so one key could work like this. If it works, it works! You just examined repair job from 45 years ago.
Amazing Goop adhesive is also a great product, and does not need to be mixed.
ehm, wait a minute, the keyboard encoder is a programable microcontroller, it should be possible to filter out the double presses in code. Specially considering this is a expected problem in those old keyboards im suprised this is not already in.
This is the kind of content I like most
Those DIP-shaped IDCs are readily available from e.g. DigiKey or Mouser for pin counts
Oooh, I'll have to keep an eye on Joe - I have a dead Mac Plus keyboard that needs a replacement. Somehow I lost my original keyboard and got this one on eBay but it was dead and I'm betting it was an incorrect cable used at some point. (Good grief Apple, why on earth did they use a cable that could be mistaken for a handset cable but be fatally incompatible!) I've toyed with the idea of using a Pi Pico to replace it but never really did any work toward that. I did find a listing of the code for the original controller, which was a mask programmed version of the Intel 8748 microcontroller. Found some on ebay, but would need a programmer and an assembler. A modern replacement would be awesome tho!
Yep, "velcro" type materials are indeed called "hook and loop fasteners"
Thoes keycaps with that gloss finish looks so beautiful
That 'L' key fix is in the running for most half-assed job of the century.
So for me the question would be which is better a machine that is as close to factory as possible or one that works well. I'd say stick with the 2 plus keyboard and if the esthetic difference the power light being flush rather than raised it should be possible to bodge together a way to move the taller power light to the other keyboard. Machines from this era always had a number of mix and match components. My first computer was a Tandy 16K machine, but by the time I retired it it had 64K, I don't remember how and an external hard drive that was connected through the cartridge slot using an adapter from a company out of Syracuse, NY. My next machine was an IBM Portable. IBM had no hard drive available so I found a half height Tandon, it would fit without its face place, I soon realized if I cut the sides off the Faceplate it would fit so I remember cutting them off with an exacto knife. At least to my way of thinking creative ways of changing them to make them keep working is equally a part of what they were and are. Just my two cents.
I've bought 2 from Joe for my //e and //c, they works great! The new replacemnt consume much less power than the original, already changed my //e and //e with WDC65c02, it consume incredible low power, means CPU stay cold all the time.
Adrian, you probably found quite a number of posts from me in your research. :)
This video made me very sad though, as you can indeed repair the switches; and still source them, albeit not inexpensively.
I had a bad flat cable on my Apple //e - floppy cables. When I opened the crimping bit I saw corrosion on the bits which penetrate the cable. I just cut 1cm and re-crimped them and it's been working since. It was such a pain to identify, the floppies were working intermittently!!
I don't suppose any modern mechanisms can be adapted to fit the board and keycaps? I mean, those keycaps looks great, so I think they deserve the effort :)
With my Apple ii with that same keyboard I used deoxit and kept pressing them over and over and over and over and over again and now they work well.
I’m now waiting for the mini mail call where someone who has seen this sends in replacement keys or a new keyboard haha! I cannot wait!
I'm betting the fact that the keyboard converts keypresses to ASCII characters is a holdover from the terminal days. The earliest microcomputer displays and keyboards were essentially dumb terminals attached internally to their host computers using the same signaling technologies that mainframes and minis were using. The Heathkit H89, a very Fallout looking all-in-one computer from the late 70s, had a toggle key on the keyboard labelled 'offline.' When it was down, the monitor and keyboard were physically disconnected from the internal CPU, and their IO was redirected to the serial port on the back of the machine. This allowed the H89 to switch between dumb terminal and computer mode on the fly. I've always wondered if anyone actually used that functionality.
There is an schematic of the keyboard on page 7-14 of the book "Understanding the Apple II" by Jim Shater. A must have book if you own an Apple II ;)
If you want a plastic safe contact cleaner, I highly recommend BW-100! It's nontoxic, non-flammable, quick to dry, and works extremely well. Only thing is that it's only available on Amazon and more expensive than most contact cleaners, plus the only available can size is rather small, so definitely get 2 or 3. It worked wonders on one of my parts keyboards. It's pretty much the only option for delicate electronics.
In the UK, we don't have JB Weld... our dominant 2-part epoxy is "Araldite"... I've often wondered, if you did a big in-depth chemical analysis, would you come out the other side and say "Yup! They're exactly... EXACTLY the same stuff!".... sorry.... back to the Apple ][ ... I love how control-G is still labelled as "BELL" although none of the other keys have their ASCII CONTROL name on them... Trying to work out what "bell" meant got me on the road, as a kid, to working out how the control key worked - I used to love to show off the fact that I could press CONTROL-[ and it would do the same thing as pressing Escape or Control-M was Enter/Return....... the simple joys of childhood.
I'd be sorely tempted to take that power LED off the junk keyboard and put it on that 2+ keyboard.
Apple ][ Forever!
These old key switch models that use basically hybrid membrane mechanical switches should be thrown in the bin where they belong. The only real key switch they should be replaced with, is a mechanical spring-snap switch like what is produced in modern mechanical keyboards. Trying to cut costs on keyboard designs in the late 70s, early 80s made these terrible design choices come to fruition. I'd take a rubber dome membrane keyboard from the 1990s with carbon contacts, over one of these abominations of materials engineering.
Modern rubber dome keyboards are pretty okay. They are plenty durable and incredibly cheap. Mechanical boards feel better of course, but the rubber domes work just fine.
@@moth.monster yeah, I’ve been very pleasantly surprised with modern dome keyboards.
One of the biggest issues home microcomputer manufacturers had to solve with early micros was that certain components like good keyboards, memory, disk storage, etc all were very expensive and at the time there was a built-in market for home micros as there is today. If you were going to sell a home micro to a family or individual that wasn’t sure they really needed a computer in their lives yet or was on a very tight budget then you needed to get the price as far down as you could while still having a usable computer. They manage this in several ways. First, they cut down on the amount of built-in memory, at least for base models. They’d get around the limited memory issue by offering an option plug-in RAM cartridge or RAM board to expand the memory or they include unpopulated RAM sockets for optional additional RAM chips. With graphics, they cut cost with offering either monochrome-only output or limited colors and using poor quality RF TV output as standard so budget users didn’t have to buy a stand-alone computer monitor. With the keyboards, they went with cheaper designs like these hybrid keyboards, chicklet keyboards, membrane keyboards, etc over better quality but much more expansive proper mechanical keyboards. The use of membrane keyboard party explains how Sinclair got the Z80 & 81 (Z81 was sold as the Timex-Sinclair 1000 in U.S.) under £100 ($100 for the TS-1000). The Atari 400 did the same with its membrane keyboard choice. Another common choice in early microcomputer keyboard design was to only include uppercase letters in the built-in ASCI character set. The Apple II and II+ lacked lower case characters built-in with IIe being the first to properly support both upper and lower-case characters. The choice to use audio cassettes for data storage over then expensive floppy disks in the late 70’s and early 80’s (and longer in the UK) was about cost cutting.
Yes, some of the early design choices dictated by the need to cut costs seem stupid today with our decent rubber dome keyboards and cheap RAM and such but back then the manufacturers had to make trade-offs. Maybe they could have picked better trade-offs in some areas but sometimes early home computer users just had to learn to accept that until the costs of certain complements come down, they would have to work with whatever the manufacturers could provide the buyer at the price they were willing to pay. Some did better then others at this balancing act but every home micro was compromised in some way. The Apple Lisa didn’t cut corners the way the later Apple Macintosh 128k did but sold for $10,0000 ($30,000 today) in ‘83 and was a flop while the Mac 128k (1984) sold for $2500 ($6000 today) and was much more successful.
They’re not all great. I picked up a generic dome PS/2 keyboard from CompUSA in the mid 2000s and I’ve managed to wear out the right shift. The dome isn’t springy anymore so pressing the key just lodges it in the stem guides at an angle.
This is a pretty cheap keyboard, so it’s not unexpected, but I think we’ll see more of those kinds of failures as low-cost 90s and 2000s keyboard get to be 30+ years old.
I remember these computers in my elementary school, specifically the Apple II+
They were nice for color gaming despite the color fringing.
With all of the parts available and remanufactured for retro computers, kind of a drag that those keyboard switches aren't.
Can I be honest.. as a serious Apple II collector.. I actually hate the single PCB A2 keyboards. They look great, but even when they're working they feel like you're typing on a Coffee Crisp. And of course 40+ years later, they're often not. I have found the alcohol + 100 keypresses trick works for a while.. but they often go back to trouble. The later II+ keyboards, before the foil tab (yuck), are the best.
Back when, computers were user unfriendly. 6 [Ctrl]+P [enter] to boot from the floppy, yeah that is completely intuitive.
That is why the Apple II came with a rather large instruction book. 😉
It depended on what slot the floppy disk controller card was in. Slot #6 was the standard. The monitor's 6^P command re-directed the system's output to whatever card was in slot #6. It was a way to give control to the disk ][ card, which would boot the system if necessary, and start watching for disk I/O commands in the output stream. It's pretty amazing how they shoehorned that functionality into the system.
@@williamgraham2468 Oh I understand the logic behind it, I am a child of the 80s after all. Just that to a novice user it could be confusing. And I am not just bashing the Apple ][, most micros of the era were horribly designed in regard to the user experience. Disk commands on the c64 are also dumb and counterintuitive. Like destroying your basic program if you wanted to peek at your disk's content.
@33:14 the proximity of the non-working keys, because it's the key switches rather than matrix driven, indicates a spill.
I've been fooled before by a completely non-working keyboard (except for the RESET key) on an Apple ///. I thought the encoder must be bad, but it was in fact the power supply - the encoder needed the negative -12V voltage, and it was missing. Worked fine the moment I fixed the PSU. If the encoder is completely bad, first check the negative supply voltage :)
Very nice. Also this implies that missing bias voltages don't damage the ic
@@Nas_Atlas In my case it didn't. After the -12V reappeared, the encoder (and the keyboard) worked perfectly.
Are you going to buzz out the bee pins? You should see a hive of activity.
00:04:38 I have found that a rigid adhesive is almost never the right call. Imagine a cookie sheet covered with a 1 inch thick coating of burned to carbon caramel. If you tried to lift the mess up out of the cookie sheet, It would take 8 million pound of force. However if you twisted each end of the cookie sheet even slightly, about 72 trillion tons of sheer force is generated and the mess pops out as a big chunk.
This is why ice cube trays work. Ice is a great glue until sheer is introduced. Since the part you show is subject to flexing, there is the issue of sheer. In these situations, a flexible adhesive is best. Better yet is a Vulcanizing sealant used in a manner inconsistent with labeling. (as a glue) RTV sealant is absolutely wicked to remove off of anything. A part like that would break if you tried to pry it off after RTV, but you could remove it by sliding a razor knife between the parts. Not only that, its Vulcanizing so you don't have to remove the old RTV to re-glue. Like retreading a tire the stuff will fuse again with itself using a a bit of new sealant between them.
RTV is different than silicone sealant. There are wild variations among RTV. Like grey RTV is generally more brittle and not a good thing for misusing as glue. Black RTV is amazingly stretchy. You want the stuff without the vinegar smell in this application. Permatex # 7651939 almost has a nice smell if you like a good new car interior off gassing. Leave a good bit hanging out of the applicator in storage. The product will slowly cure down the tip after 6 months of not use. This can usually be removed repeatedly, allowing the whole can to be enjoyed.
Discard first quarter size glob from the tube and don't use the very very last bit out of the can either. (it will start coming out excruciatingly slow at the end, but will seemingly do this forever)
IDK which is worse, a broken colon or a stuck colon.
That connector from the encoder PCB to the keyboard is a common failure point. The sweeps on the sockets corrode and break off. I have not found any modern replacement that's anywhere close.
Love these vids!
I (kinda) recently bought those connectors. I've gone over all sites I could think of, and couldn't find where I ordered them from. I remember it was Ali Express, but I can't find it in my orders history.
I added a reply to the actual place I bought it, but it appears that putting a link will get the reply erased. They are available, new, if you search the correct site for the name "DIP flat cable plug".
There was a difference between the ][ and ][ Plus motherboards - the Plus boards had a "color killer" circuit enabled in text mode, eliminating color fringing around characters that was present on older boards.
I can’t believe there wasn’t a class action lawsuit for Apple intentionally destroying keyboards if you tried to use them without their “official” cable. Can you imagine if they tried something like that nowadays?
An enterprising person could probably design a 3d printed replacement keyswitch assembly.
I disliked the original keyboard for a couple of reasons, though I only had my Apple II for about 3 years. That raised power light got _hot_ and was easy to accidentally roll the heel of your hand into and get an uncomfortable "sear". The lowered one was relatively safe. And if you did not have the "Ctrl-Reset" modification, as mentioned it was too easy to accidentally slip and hit "Reset" at inopportune times. It was common practice to pop loose the lower half of a clamshell cassette box and lay the corner over (around) the "Reset" key so that you had to actually move the box to depress the key.
I hope someone starts making replacement switches
I wonder if you could make some sort of 3D print that would take the space of those long switches so you could replace them with say cherry switches. Recycle legs from components you snip on another project. Probably would be very involved but needed eventually.
Could someone just design a whole replacement keyboard using Cherry switches?
@@JeffTiberend Absolutely. I was just thinking to replace the part that is broken. PCB works fine. So making cherry switches the form factor of those switches is probably the most original fix possible.
Short leads and some hot glue make you the key switch rebuilder you want to (be).
The DIP IC sized IDC connector looks like a TE part 5746613-3.
Suppose that tape was to prevent grounding pins against the nearby metal frame?
Huh, wow, I'd put that bodged key in a display-case! XD What a creative way to fix a key.
Somebody should print adaptors to mount these key-caps on different switches.
With a shorter switch it'd be possible to have it look stock, or nearly so depending oh heights.
Maybe a mounting frame to hold the switches in place as an alternate to the screws could be printed too?
Joe out there doing god's work
It would be something if someone would make replacement key switches for that key
anything digital that requires a negative voltage like a DRAM, or some very old NMOS logic devices will be damaged NOT ONLY if a bias voltage is missing, but also if the voltages come up in the wrong order. Many old devices sized the filter caps to ensure startup in the correct order, some better commercial computers like min-computers form DEC actually had circuitry interlocks to grantee correct startup of power supply voltages
Too bad some one hasn't come up with a 3D printed Key Switch fix for these keys
Awesome channel have same Apple II same keyboard same issues. I have three keys not working Y,2, and 4 and some double type keys. I was going to buy that encoder you showed but think that may not fix my keys because every other key works correctly(IE they are not ALL out) I have two extra new keys switches may buy a few more. But to change them I have to know how to solder right? My double entry keys should I buy new key switches for those too? I am guessing, yes... anyways really enjoy your channel learning a bit about chips and how they work on that board cool!
I guess it's design another PCB with different switches, but knowing Apple the plungers are probably a one-off that no one else uses - lol -.
Thankkss for thiss video. I enjoyedd itt 💙
That PIC in the replacement keyboard controller is higher performance than the APPLE ][.
Thank you! Now we know how 'The Matrix' works! : ))
Adrian, I believe it is possible to buy these switches or else, use the plastic cages and refurbish the inner materials.
Since the encoder is a custom chip now, can you also have it customized to debounce the keys that are registering double presses?
Do the keyswitches have the same footprint and height as any modern switches? Would it be feasible just to replace the lot?
I feel like this is one of those cases where you have to choose between "make it work" and "keep it original", and the "make it work" option would require a modern replacement of the keyboard pcb with one made brand new using off-the-shelf switches. But "keep it original" that you seem to have gone with is also an option, it just won't be working very well as a keyboard.
The keyswitches look surprisingly similar to modern "cherry" switches, it makes me think that a 3d printed adapter or similar might be possible?
Joe, come up with replacement keys!
Now you know how they get to creative labs exxtreme !!!
You should have placed the bad keys at H L O W R and D, installed a spy cam, and sold it at a flea market. 🤣
Holy cow! Looking at that bodged key, i am both inspired and disgusted. Somebody did amazing work to get a switch that works, but on the other hand, just replace the switch!
CT6502 has a vid on how to build an entire new keyboard from new parts and PCBs.
Too bad there aren't replacement switches. I'm thinking there may be, but would require quite a bit of modifications to the PCB as the pins may not fully line up. It would be interesting to see if anyone starts a side-project on restoration of these keyboards, even if the onboard chips need to be transferred to the new PCB and replacement key switches.
and maybe 3d print a small thin adapter to allow the original keycaps to fit modern switches.
I want an apple ii just to use quicken software on every day lol
So think of many touch screens, they use a resistive matrix or LED matrix
the double pushing keys I wonder if a small capacitor somewhere would debounce them.
You know not a bad idea -- also though, since the microcontroller is laos aftermarket, it could theoretically be programmed to ignore such quick keypresses -- faster than a human might push them