Atari 800 keyboard fix (Mitsumi membrane)

In part 1, I found out that this beautiful Atari 800 has the dreaded Mitsumi keyboard. It feels nice but the membrane fails, making the entire keyboard inoperative. After reading some information on possible fixes for the keyboard, I give them a try.
Part 1: • Troubleshooting the be...
Part 2: This part!
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[@adriansdigitalbasement]

Hi everyone -- several people pointed to the membrane at Sell My Retro but didn't notice this is for a pre-order with no ETA. May be helpful in the future but isn't at the moment :-) www.sellmyretro.com/offer/details/replacement-atari-800-keyboard-membrane-%28mitsumi-56-_7324a%29-pre-_order-38662

[@JohnDoe-qg6hm]

Hi Adrian, Just wanted to say that i enjoy your channel and hope to learn more about electronics and computing by watching you repair microcomputers. Could you perhaps have a short segment listing some of your favorite or preferred books on these subjects ? Hope you can. Thanks.

[@Walczyk]

@@administratorwsv8105 okay pal, you are really rude

[@HunterZBNS]

@@administratorwsv8105 I'm skeptical of this. Adrian tried really hard to determine whether it was an alignment issue, and wasn't able to get an improvement. Separating the membrane then made a dramatic difference. You'll need to make a better argument to account for these empirical results.

[@jamesrowden303]

@@administratorwsv8105 This channel doesn't have any content

[@jamesrowden303]

Nuff said about them.

[@frankrahman341]

When you want to look for alignment issues place a piece of “carbon” paper between them, screw them back together and press every key. When you separate them you will see the points where the keyboard is pressing on the board.

[@ovalwingnut]

GR8T idea. You are truly.. Top Rahman. And who doesn't like that!

[@kissingfrogs]

I was thinking of dabs of nail polish or some slow drying paint, but your carbon paper ides nails it. I really wanted to see the key points and how well they aligned with the dots.

[@billdberger7407]

yep that's what dentists do to properly fit a filling to the corresponding tooth.

[@djp_video]

The Esc key seems to be working fine, as designed. The way it works on Atari 8-bits is pressing Esc puts it into a mode to escape the next character for inclusion in a string... so pressing Esc twice first puts it into Escape mode, and the second Esc is actually added as a character in a string. And if you were to do Esc then Up arrow, you'd see an Up Arrow character instead of actually changing the cursor position. Atari used this to do things like clear the screen, move the cursor, line breaks, etc. while outputting a string to the screen, like from a PRINT statement in a BASIC program. To clear the screen, for example, you'd enter: 10 PRINT ", then press Esc then Clear, then close the ".

[@kevin34ct]

Esc was a double press to get something on the screen

[@absalomdraconis]

Sounds similar to ANSI terminal escape codes. Wonder how much overlap there is.

[@markjreed]

Right. On the Commodore an open quotation mark or the INSert key would cause special characters to show up as an inverse video symbol; ESC is like Atari's version of that. So Esc by itself doesn't show anything, but Esc twice prints the "Esc" symbol.

[@iceowl]

@@absalomdraconis Atari had its own version of ASCII called ATASCII. there are similar characters to ansi, but also very different characters.

[@kazriko]

One of the things I did the most with my Atari was a small program that worked similar to this. You would enter characters in to move around the screen and change things, and it would record the entire key sequence and then you could save that to a file, then if you loaded the file it would play the whole thing back as an animation.

[@ThomasTalbotMD]

ESC key is fine - you have to press it twice to see the ESC character, otherwise ESC + another key provides a second function. Great job on repair.

[@ihatemybosses]

In the early 80's I spent many afternoons after school typing in programs into my Atari 800 from the latest issue of Compute magazine. These were programs. None of this calling them Apps BS haha. Graduated to a 520ST. What memorable days those were.

[@MrLurchsThings]

The 800 is absolutely on my “grail” list. Great to see it all up and running again 👍

[@nickolaswilcox425]

good luck on that, its the model in the family that most people want by name and it seems to be on the rarer side with relatively few being available at any point in time, took me months on mine and i had to go for a nonworking one to get it at all, granted it was an easy fix but still

[@davecardboard9567]

LOL - I've got an (my) Atari 800 I bought as a teenager still in a cupboard! Who knew they would become a collectors item!

[@shamrice]

@@nickolaswilcox425 eBay seems to always have some floating around for sale. They're on the more expensive side (not being sold for just $20 bucks anymore) but they're still pretty easy to get a hold of if you want one.

[@nickolaswilcox425]

@@shamrice that wasnt so much the case when i went looking so my perspective might be a tad off, but when i was looking there were only 2 or 3 and all on auction with too much time left and a bidding war already in motion so no way in hell i was gonna try for them, plus i dont generally pay a collector price for my systems and make every effort to avoid it mine i managed to grab for around 100 and had it back to working order about a day after getting it

[@MrKeving1]

I found mine at a garage sale for $80.00 with aftermarket printer and disk drive tons of programs and books

[@vwestlife]

The internal speaker also generates the system beep, for example if you press Ctrl-2 or type PRINT CHR$(253).

[@iceowl]

and booting sounds too iirc, which is useful for troubleshooting. or just knowing if you forget to close the floppy drive. :3

[@PG-gs5vb]

@@iceowl the booting sound is actually generated by POKEY.

[@NoelsRetroLab]

Great job! It reminds me how I fix ZX Spectrum +2 membranes by taking them out and rolling them into a tube. It seems pretty similar except that here instead of being two layers of plastic, it's just one layer making contact against a PCB. But the solution seems to be the same: To unstick one layer from the other.

[@JimmyCall]

Missing your content. I hope you've moved homes by now!

[@tony359]

@@JimmyCall - Same, Noel! :)

[@Lirchicus]

My first Atari computer was the Atari 400, but one of the first things I did was replace the keyboard with an after market mechanical keyboard and expanded the RAM. Later I bought an Atari 130XE form a friend... it had been hacked to run 512K (big ram disk) and with that and seven floppy drives (not Atari drives and Lambda power supplies for everything, including the computer). I ran a BBS on it for several years. I eventually ended up with a 1040 ST and for a while, I was one of the Atari Sysops on Compuserve. It was a fun time.

[@aCivilServant]

Atari 800, the father of the Amiga thanks to Jay Miner's genius.

[@LeftyLabs]

Good job on the keyboard fix. That Mitsumi keyboard design is very, very similar to the 1200XL keyboard, though on that particular model, one of the most common ways for them to fail is at that contact strip toward the bottom. The carbon traces get diffused and embedded into some tape material Mitsumi used between the silicone insulator layer and the traces. On the 1200XL, the “canonical” fix is to remove the old paper tape over that contact strip and repaint those traces with carbon conductive paint, then reassemble. I’ve done two of my 1200XLs with that fix several years ago and they still work great - it’s slow and tedious to disassemble those keyboards and remove the silicone layer to access that contact strip, but it’s worth it.

[@IanSlothieRolfe]

if you want to see a game that was ahead of its time, get a Star Raiders cartridge, a 3D shoot-em-up based vaguely on the old Star Trek games from mainframe days, but with first person pursuit and battle, with shifting star fields and enemies that dart backwards and forwards around you while you try to shoot them down. Considering it was written in the late 70's when I first saw it I was transfixed and used to hang around the computer shop waiting for my turn to play it! It's not the best game that was ever made for the Atari, but it was the best of the first games made for it and still my favorite to play. It played like an arcade game at a time most home computers couldn't hope to do so.

[@jameschamplin1742]

I play Star Raiders a few times a week on my 800. Amazing experience for 1979.

[@zzznrrr]

Playing Star Raiders on a 400 made me want an Atari back then, went for the newer 800XL later :-)

[@jerryspann8713]

Actually Dell, HP, Intel keyboards have this same construction. However when working on the newer keyboards, the film layers just come apart if there is no liquid spilled inside the keyboard. The company I worked for would that refurbished computers would also refurbish the keyboards as well. We would take the keyboard completely apart, clean the keys, clean each layer of the membranes and put it back together. Ones that wouldn't work previously would work perfectly afterwards.

[@ChristopherGaul]

Watching Adrian's videos is an exercise in being shamed for how impatient you are compared to him. I'd have thrown that thing across the room about 10 minutes in. Congrats on getting it working at all.

[@stevemcknelly5036]

Atari's were my first computers -- I had an 800XL and a 130XE. I normally really enjoy your content, but these videos have been something special to me. Thank you for making them!

[@sideburn]

Same. And then the 300 baud modem that launched my software piracy career 😂

[@anthonyferguson7158]

@@sideburn 1030 or XM301?

[@sideburn]

@@anthonyferguson7158 1030... And my home brewed BASIC ATT credit card phreaking app + a Happy 1050 drive and i was the neighborhood pirate king LOL

[@anthonyferguson7158]

@@sideburn I started with a 1030 and an 800XL myself and ran a BBS in GA from 1984-2000. :) I had a few US Doubler 1050s as well and dabbled with PBXs and phreaking. Yeah, I had a few private sections for my friends too, and people knew where they could find a bit of everything...hehe! Good times. Wish I hadn't given my drives and 800XL away. I still have a good number of the floppies.

[@sideburn]

@@anthonyferguson7158 wow that’s a long run all the way to 2000! I still have a lot of my original floppies. Unfortunately the ones with my programs I wrote are all unreadable. I just recently fixed my 800xl, 130xe, and 1050. Do you happen to remember a BBS called Gecko in California? His was pretty popular but I haven’t t been able to find any info on it. He was a friend of mine in the neighborhood. Always wondered what happened to him.

[@Colin_Ames]

Excellent video, as always. I am glad that your perseverance paid off, and the keyboard is now fully functional.

[@itzcaseykc]

Great that you were able to get the keyboard working. It's always kewl when one obtains their objective and can see positive results of their labors. Nice job!

[@haraldweinreich9522]

I was an absolute Atari 400/800 fan. Please show more of these videos! Your videos are so informative!

[@themaraudershideout3010]

I don't know if anyone has mentioned this yet but the Atari 2600 and 8-bit computer line was done by Jay Miner who also did the Amiga so the Atari 800 has a lot in common with the later Amiga as you mentioned the 800's 256 color palette along with the Amiga. I love my 800 and it outputs very clear RF and Composite. Thanks for the video, as I have yet to have a keyboard issue on mine but now I know what to expect!

[@andreasklindt7144]

You did a wonderful job! I love seeing old tech getting repaired, it feels like paying respect to the people who spent hundreds if not thousands of hours into developing and engineering it an writing games and programs for it. I also wonder how many Atari 800s or machines with similar keyboards ended up in the trash that could've been relativ easily been repaired like this one. Also worth mentioning: Half a year ago I've found an old Linux game from 2007, called "wordwarvi" (yes, without l...), that is still available in some repositories. It looks, feels and sounds very similar to Atari's "Defender".

[@kitchentroll5868]

It has been 20+ years ago, but I rebuilt a Mitsumi membrane using an X-acto knife, a paper hole punch, signage vinyl, copper tracing bodge wire, Avery hole reinforcements, and the power of OCD. It worked, but I cannot recommend my method. It was two weeks of my life that could have been better spent.

[@penguinsushi8442]

Making the surface of carbon membrane rougher through light sanding is a great way to remove the shiny/sheen and stickiness of keyboard keys/TV remote buttons.

[@eddiepetrick6222]

As others have said, that's how the escape key is supposed to work. Twice to get the Esc character.

[@GORF_EMPIRE]

The Atari 8 bitters were well ahead of their time and even stayed technologically relevant long after.

[@dunebasher1971]

Atari designed so much power in at the start that they were still superior to most 8-bit machines even as the 16-bit era began.

[@GORF_EMPIRE]

@@dunebasher1971 The PC never convinced me to move away from my Atari 8 bit till the 486.... even then I loved my 8 bit and ST more. However, I could not play Doom or Wolf 3D on those.

[@endersftd]

26:50 And just like that, I was brought back to my childhood with the hand-me-down Atari 800 I had.

[@williamlyerly3114]

As I watched, your trials and tribulations reminded me of the fail ing U.S. torpedoes at the beginning of WW2. Each failed keystroke was equivalent to an individually failed launched torpedo. You did well. Took them ~2yrs.

[@GantryG]

Good job keeping on it to fix that problem! Beautiful machine!

[@technicaltaurus1]

There is an Atari parts company called Best Electronics that is near the Atari warehouse in Sunnyvale. The people at Best have replacement parts and keyboards for all Atari systems except the one keyboard you had issues with! They only get one request about every 10 years for replacement Mylar for those late in production run 800s. The only options I am aware of are to clean and if necessary recoat the contact points and bad traces with liquid silver pen or nickel print paints, or purchase a cartridge which provides a USB connection and plug in a USB keyboard. You will need to drill a notch in the cartridge door for the USB cable (ugh!) You were fortunate to make it work!

[@freeculture]

The amount of metal in those machines was amazing, and while every single youtuber fails to mention it, the cartridges too have metal!

[@thebiggerbyte5991]

A really lovely machine. I've wanted one since I was a kid. The looks, the build quality, the features. And an easy fix, too. :)

[@Potts1966]

I'm really liking these somewhat longer videos where you spend some time fixing things.

[@Clavichordist]

This was my second computer. I had an Atari 400 that I gave to my cousin and she used that for ages when I upgraded to the Atari 800 which I added memory boards to. I think there's something missing on your memory cards. From what my old brain says to me is there was a pressure bar or something to hold those PCBs in place but I might be mistaken on that. Heck, it's been 40-plus years now. If it wasn't for the Atari 800 and Atari BASIC, I would never have been interested in computers. I had built electronic kits from Radio Shack, but it was my Atari 800 that introduced me into programming. I learned Atari BASIC inside and out and wrote a few programs at the time. When it came time to take college classes, I took some programming classes. I had the understanding behind me of BASIC before I took the class. Remember, this was the 1980s and BASIC was considered a real language back then. In the end, I chose hardware engineering and ended up as a hardware tech instead, but the Atari was the kernel of it all.

[@kissingfrogs]

Nice video. Good to see you had success.

[@leesmithsworkshop]

I have an 800xl that was stored under leaky batteries and I have three episodes when I get it working, one episode was just on the keyboard pcb, I never saw anything like it.

[@tomjones1660]

@adriansdigitalbasement I had the same exact issue with the dreaded Mitsumi keyboard. Followed your repair exactly sans I was a able to peel up the membrane without a heat gun. My original Atari 800 from childhood is now working! Thank you so much for your fix video! -- Tom J 😊😊😊

[@macdaddyns]

One of my first hustles was taking all the PET and C-64 computers from my high school home for the summer and cleaning and repairing them. I came up with a keyboard repair that works to this day. I would take the keyboards apart and clean the carbon contacts and rubber plungers with a white gummy eraser and 70% Isopropyl alcohol and reassemble them. They worked flawlessly for the next school year. A great way to earn a few hundred bucks towards Electronics Engineering school when I graduated.

[@demofilm]

there is a way to regenerate the membrane side with some rubbing of a lead pencil some times the carbon layer is not reactive enough and re apply the carbon helps a bit.

[@Vermilicious]

Built like a tank, except for the keyboard membrane. Nice to see the machine fixed. It's a looker.

[@joe08867]

Awesome, glad you got it working.

[@mrsam6751]

Great video.. I had one of those and loved it too. 100% worth saving and keeping active.

[@hartmutholzgraefe8043]

With mine just cleaning the actual PCB with isopropanol did the trick, and I was also lucky that the foil could be removed without help of heat. Thanks for encouraging me for giving it a try after all :)

[@antonnym214]

Well done. I guess you found out the Escape key is working like it is supposed to. All good wishes!

[@markthackray3185]

Fantastic video! Subscribed

[@emilygrae]

What a pain of a keyboard! My Atari 800 has the square posts with metal contacts. I didn't know how lucky I was! My only keyboard problem is that I'm missing the keycap for the "g" key. Also, when you put the felt in the back with the RAM it reminded me that my 800 had a piece of plastic that went across the top, just like your felt, that held the RAM cards in place! I love your channel, thank you!

[@g0bzy]

I think you nailed it when you said the push part had worn out the membrane pad at that point. And thats why your finger was able to make it work. So moving things around got a fresh piece of pad contact. Basically the membrane is worn out but giving at a bit of clean and maybe a slightly new position seems to be good enough to make it work again. If it does it again, you may need a new membrane. Great to see it working!

[@andrewb9830]

Looking forward to seeing what you do with the Atari 8bit family of computers. I recently started my own first time exploration of this line with a 400, 800XL, XEGS, and 130XE. Coming from the Commodore clan it’s interesting to finally see the competition from back in the day.

[@adriansdigitalbasement]

Thanks to patron Super Sparky, he pointed me to a PRE-ORDER replacement membrane for this board: www.sellmyretro.com/offer/details/replacement-atari-800-keyboard-membrane-%28mitsumi-56-_7324a%29-pre-_order-38662 No idea if/when it'll get made.

[@gamedoutgamer]

Adrian, the replacement mylars were made. They didn't work. They depress all keys at once. I have two of them. It might be that they need the rubber layer as the Mitsumi. I can send you one if you want one. I did reply in the previous 800 video with the fix that you mostly did here. Very glad you got it working! Read on please. There are at least four types of keyboards for the 800. First the female square-plunger variants. They are true mechanical keyboards. Yellow plungers (stackpole, uncommon or rare to find) are the worst. Keycaps fall out very easily due to plungers cracking with age. White plungers (HiTek, most common) still do crack but they hold the keycaps much better. Green plungers (Stackpole, somewhat rare) are the best of these types. They are all truly mechanical with 'wings' connectors visible when removing the plungers. The Mistumi you have are most like the 1200XL and while finicky have perhaps the best typing experience. The Mitsumi's are the only 800 keyboard with a mylar. The greens plunger Stackpoles also type great too. None of them type poorly ofc. As far as graphics/capabilities it depends on the game. Games native to the 800 can have better graphics than the C64. When a game takes advantages of the hardware of either platform, it will be best on that platform. You'll see a much higher framerate on the 800 for games like Return from Fractalus or The Eidolon or the newly ported games Stunt Car Racer and Total Eclipse. Then look at Yoomp!. They did a C64 version that shows well how there are graphics that the Atari's can do that the C64 can not. But other games that are native to C64 look better on C64 of course too. Atari got a bad port of Commando for example, too. Pitstop II is much better on C64. Paperboy looks great on C64. C64 got music for Ultima IV. They could have added a 64K RAM check for Atari version but no they just completely omitted it. Atari got no Ultima V or VI =( =( Spy vs Spy 1 is native to Atari and the graphics fill the screen better and I think are better (more colorful) on Atari. I even much prefer that game's music on Atari because it has levity and punch. Also I recommend trying Blue Max on Atari and listen to how well the sound effects are done, much better than C64 version. The big plane sprite shows the better sprite engine on C64. Still prefer the A8 version due to sound and color use. The general rule of thumb is that early 80's games will usually be better on Atari 8bits, and later 80's games will be better on C64 either due to bad porting or the exploiting of hardware unique to each machine. Oh check out Gyruss on Atari.. Fantastic music and color that the C64 version lacks, but the C64 version has a better framerate. There is a modern 'bugfix' of Gyruss for A8 but the original version is fine to play too. What you are experiencing is very often true. The Atari machines often work well still to this day. They were built well. The IC's run much cooler (at lower voltages etc) and were likely fabricated to higher standards. The late-era XE machines were built to lesser standards, however. They often still just work but not always. I made a tutorial video on how to use these machines please watch it. You will learn a lot. The first seven minutes are skippable where I cover the hardware kzbin.info/www/bejne/o4G0q3eklqamZsk Very, very few people saw 800's in the 70's. It's really an early 80's high-end computer. Very few were available at the Nov '79 launch. Yours was made in the 6th week of 1983 by the date stamp code on yours. God bless you and thank you for the video and I shared your joy in this video and many others of yours too.

[@rbrtck]

You probably won't want to unplug the internal speaker because some games (and maybe some other applications) use it for sound effects, especially ones that are ported from the Apple II, which has a similar speaker. One example that springs to mind is the _Ultima_ series of RPG games. And yes, the 800XL and later models lack the internal speaker, and route its output through the TV/monitor instead.

[@MrMe4444444]

I totally forgot what the sound of the speaker was. When you demoed it at the end my memories from jr high came back.lol awesome.

[@johnvaldez8830]

Membranes are such a mess. I'm not really sure why the the little black nodes stop working...whether it is dust or debris or they get slick and polished. Alignment is often an issue and like you said, the pcb is usually clean and a bit of alcohol often does the trick. I really, really enjoyed this and I have to admit, I smiled at each step because it just seems like this is the way it goes when these keyboards are being fixed. Good job and glad to see that it's not just me when i am fiddling with this stuff. Very satisfying video!

[@bornagain2641]

Excellent job 👏

[@InterCity134]

Good stuff. The changeable basic cart was very useful. This machine gave me my first experienced when Microsoft. Microsoft BASIC cartridge was available. Though I mostly programmed in A+ BASIC loaded from floppy disk from DOS 2.

[@shaynestephens]

Great video! My first computer was a VIC-20, my second was an Atari 400 then an Atari 800. All within a year! I miss my 800. It was a fantastic computer! Enjoy it! My 800 keyboard was not the membrane type. Each key has two metal tabs that came together when the keycap was pushed.

[@oldguy9051]

You can disable the keyboard click from BASIC with a POKE 731,255 and enable it again with a POKE 731,0.

[@ehudgavron9086]

Fascinating stuff, and very methodical. Great presentation, and awesome fix. I used to hack on the Atari 400 in high school, and eventually the 800, and then, in college the Amiga 500. The Atari was always my favorite because I mastered 6502 machine language and the Atari memory mapping first. When you insert a cartridge it memory maps it to an area where there is no RAM. Maximum RAM was 48Kbytes, on 3 cards of 16K each. The cartridge(s) would map above that to complete the 64K of addressable space. One third-party created a cartridge where half was permanently mapped, and have was switched as needed between multiple banks IN that cartridge so they could fit more in less. Another third-party created a cartridge where the R/W could be enabled via a toggle switch on top... so one bypassed the "open case shutoff" like you did and keep the lid open... load up a "disk loader", browse the disk for saved cartridges, load it up, set R/W to no W, and reset to run your new "cartridge." To save to disk, run the loader, remove the pseudo-cartridge-with-toggle, then *QUICKLY* insert the real cartridge hoping it won't fry some logic somewhere, and then save to disk. Brilliant. The system bios(lowercase) checked if it could write to a particular memory space. Yes meant it was RAM. No meant it was a cartridge and it would jump to a particular address to execute. Copy protection on floppies (yeah, 5.25") was done by the application checking if it could read a particular sector. On a copied floppy it could, and it would refuse to run the copy. On the original, the factory had put "bad sectors" which would not load. In time we figured out how to make the copy, then change the fdd speed and write the bad sectors (from a sector map utility) and that worked too. The original 400/800 shipped with the CTIA chip, which was Atari VCS style graphics capable (later renamed to 2600 when the 5200 came out) and it was eventually replaced by the GTIA, which supported more simultaneous colors per scanline and more sprites. That was a user-serviceable replacement, a far cry from today's copyright-excuse anti right-to-repair world. If it wasn't for learning 6502 I never would have graduated to learning VAX-11, became a VMS hacker, and gained the perspective of how hardware works, including CPUs, opcodes, registers, memory-mapping, virtual memory (hence my note about that third-party cartridge), etc. Good times. Thanks for the memories, the video, and congratulations. Ehud Gavron Tucson AZ

[@rbrtck]

I'm pretty sure that cartridges (in the left slot on the 800) actually map to $A000, which is at the 40K mark. You have to remove the cartridge in order to use the 8K of RAM that it displaces. Above 48K is the OS ROM (and extra space reserved for future OS expansion, which the XL and XE series utilize) and I/O memory map. The CTIA chip is *not* the same as the TIA chip used in the VCS/2600. It has all of the 400/800's graphics modes and sprites except for the three that would later be called the "GTIA modes", which are GRAPHICS 9, 10, and 11. The GTIA chip also corrects the misalignment between background and player-missile graphics (sprites), which has the side-effect of reversing the artifact colors in the hi-res (320x192) mode (GRAPHICS 8). The GTIA chip only adds some modes that allow more colors to be placed horizontally across the screen (albeit with only 80 pixels of resolution), it does not change any other modes or add any sprites.

[@jessedunn3766]

I've always had great success using the eraser on the end of a pencil to clean membrane keyboard component and even pcb card slot contacts.

[@fred_derf]

You're better off using a Mars plastic eraser, they don't leave residue like a pink pearl.

[@user-wk5pq7et3d]

I had a similar situation on the Atari 130. I tighten the screws, it stops working. Relax - it works. As a result, I put spacers between the membrane and the case - everything works well

[@ThomasFlemingOriginal]

I came here to say this. When I was fixing my 600xl I found the same. If the screws are over tightened then the keyboard won't work.

[@ericp.ziegler14]

Awesome video and repair! I’m wondering where you acquired the DIN output to S video converter cable you show during the video for alternate video output? I’m still using the RF output and it has a lot of noise associated with it after years of use (or non-use as it were!). Thanks so much and love all the great videos. Keep up the good work.

[@maxw7221]

I received a TI-99/4a today with a Mitsumi keyboard with problems, so I came back to this video. Using a fiberglass scratch pen to clean up the pads made it easier. It freakin works!

[@Anangelspath]

You probably won't see this but here is a cheap and easy fix, get 2.5mm(?) heat shrink tubing, cut in approx. 2mm "cylinders" and put over the "nubs", alot of cutting to be sure but not bad. I fixed two 1200XL and 1 TI-99/4a keyboards this way, it works. I think the sizes are right, I made the video a long time ago about this.

[@davidorama6690]

Love your work 👍

[@aussie_retro_dude9253]

Great Video 👍

[@marklechman2225]

I’ve had three of these over the years because the space bar keeps going out on them. It’s easily my hands-down favorite retro gaming machine.

[@andrewclegg9501]

My 1983 PAL 800 had a mechanical keyboard. I seem to remember it had a plastic strip across the top of the ram cards with slots in it to hold them stable. Either that, or I made it. My current 600XL has a really nice mechanical keyboard, its smaller than a bread bin, much more practical permanently on my desk than the 800 would be, but no where near as cool or bomb proof. Regarding SID vs POKEY. Both is my answer, POKEY for sound effects, SID for music. POKEY was designed at a time when no games had music, and only arcade games had good effects. It can do good music, especially these days with amazing home-brew coders, but back then, no one had a clue how to use it for good sounding music. There's 2 POKEYs in my 600XL, 8 channels. Someone did a FPGA which had 2 POKEYs, 2 SIDs, and a Yamaha FM synth, for the Atari, but the chip shortage has screwed that up. I love the old sound chips, each machine having a distinctive voice, not all sounding generic. Apart from stuff with AY chips, thats super generic sounding, but can sound good in the right hands. The GTIA generates the clicks for the keyboard, this has been used to produce music too, its a bit 48k spectrum like. On the XL and later models, its mixed into the standard audio output so can be used as another channel.

[@tjlazer71]

Same issue happens on the 1200XL. I found that pressing down all the keys many times brings them back to life.

[@HAGSLAB]

This fix would really annoy me, because it feels so temporary and the keyboard will probably fail again at any time. Good thing you figured out the issue though and that it's working for the moment. Hopefully some replacement membranes will become available. Nice video Adrian and cool machine 😊

[@jkeelsnc]

I always have liked the Atari 800/xl. Neat machines. And I say this as someone who grew up with the C64.

[@NerdThingsAndMore]

Good video thanks

[@josefont11]

Adrian, thank you for the videos. I like very much to watch you working on a broken computer. I watched you work on the Atari 800. and I got hungry for one. Do you have any advice on what to look for if I were to buy one? thank you.

[@shaiseg]

I think the reason that it worked with the finger but not with the keys is that the keys press on the center of the membrane pad, while the finger press the entire pad. The center of the pad lost its conductivity. This is also why offsetting the pcb helped, when the keys now pressed the the pad off center.

[@Barnaclebeard]

Wooo pixelshatter! Love Defender.

[@MajenkoTechnologies]

The raised nubs on the PCBs are known as Mouse Bites and are where the pcbs are joined together as big panels during the manufacturing process.

[@jameslewis2635]

Good job with getting that keyboard working. I would have been thinking to convert the keyboard to use mechanical switches. Yes, that would be a bit of a project but I would expect better results than with a membrane. The other idea I had was to obtain some carbon domes (like the ones seen on the Atari ST) and use them in place of the top plastic layer.

[@dastardlyexperiments]

Just so you know there are two rotatable clips which should be where you have the two screws holding the top case on. Yours are missing - do an image search. (I own an 800 which has them..) Wonderful machine, and great luck with the repair not needing new components. 👍

[@Mrshoujo]

That keyboard speaker is actually a 5th audio voice for the Atari 8-bit! I saw one music demo which used it used as such. BEST Electronics might have the parts you need for replacing the keyboard.

[@gamedoutgamer]

Unfortunately, BEST doesn't yet have the 800's mistumi mylar, only for the 1200. Wouldn't take much to adapt it!

[@indisputablefacts8507]

I'm still in possession of what is probably the only 16-bit upgrade for an Atari 800. (I strapped a Motorola 68000 into one of the expansion slots and made it sorta go for a Computer Engineering class in 1986 or so.) Doesn't work anymore - pillaged it for chips back in the day, before the whole thing landed in a box that moved with me forever.

[@richardbrobeck2384]

this computer is still on my wish list !

[@gamedoutgamer]

Adrian, the replacement mylars were made. They didn't work. They depress all keys at once. I have two of them. It might be that they need the rubber layer as the Mitsumi. I can send you one if you want one. I did reply in the previous 800 video with the fix that you mostly did here. Very glad you got it working! Read on please. There are at least four types of keyboards for the 800. First the female square-plunger variants. They are true mechanical keyboards. Yellow plungers (stackpole, uncommon or rare to find) are the worst. Keycaps fall out very easily due to plungers cracking with age. White plungers (HiTek, most common) still do crack but they hold the keycaps much better. Green plungers (Stackpole, somewhat rare) are the best of these types. They are all truly mechanical with 'wings' connectors visible. The Mistumi you have are most like the 1200XL keyboard and while finicky have perhaps the best typing experience. The Mitsumi's are the only 800 keyboard with a mylar. The greens plunger Stackpoles also type great too. None of them type poorly ofc. As far as graphics/capabilities it depends on the game. Games native to the 800 can have better graphics than the C64. When a game takes advantages of the hardware of either platform, it will be best on that platform. You'll see a much higher framerate on the 800 for games like Return from Fractalus or The Eidolon or the newly ported games Stunt Car Racer and Total Eclipse. Then look at Yoomp!. They did a C64 version that shows well how there are graphics that the Atari's can do that the C64 can not. But other games that are native to C64 look better on C64 of course too. Atari got a bad port of Commando for example, too. Pitstop II is much better on C64. Paperboy looks great on C64. C64 got music for Ultima IV. They could have added a 64K RAM check for Atari version but no they just completely omitted it. Atari got no Ultima V or VI =( =( Spy vs Spy 1 is native to Atari and the graphics fill the screen better and I think are better (more colorful) on Atari. I even much prefer that game's music on Atari because it has levity and punch. Also I recommend trying Blue Max on Atari and listen to how well the sound effects are done, much better than C64 version. The big plane sprite shows the better sprite engine on C64. Still prefer the A8 version due to sound and color use. The general rule of thumb is that early 80's games will usually be better on Atari 8bits, and later 80's games will be better on C64 either due to bad porting or the exploiting of hardware unique to each machine. Oh check out Gyruss on Atari.. Fantastic music and color that the C64 version lacks, but the C64 version has a better framerate. There is a modern 'bugfix' of Gyruss for A8 but the original version is fine to play too. What you are experiencing is very often true. The Atari machines often work well still to this day. They were built well. The IC's run much cooler (at lower voltages etc) and were likely fabricated to higher standards. The late-era XE machines were built to lesser standards, however. They often still just work but not always. I made a tutorial video on how to use these machines please watch it. You will learn a lot. The first seven minutes are skippable where I cover the hardware kzbin.info/www/bejne/o4G0q3eklqamZsk Very, very few people saw 800's in the 70's. It's really an early 80's high-end computer. Very few were available at the Nov '79 launch. Yours was made in the 6th week of 1983 by the date stamp code on yours. God bless you and thank you for the video and I shared your joy in this video and many others of yours too.

[@organiccold]

Nice Atari and easy fix

[@Scherrah1010]

I had trouble with these Mitsumi membrane keyboards myself. The white layer you have ripped a little is the contact layer with carbon caps just over the PCB contacts. So first thing one can do is to lift off the membrane/contact layer gently using the heat gun method and then apply IPA with 99.8% purity onto the PCB contacts. The carbon spots can be re-fitted using graphite in a decent amount or, like you did, gently grind off some of the „used“ graphite layer from the rubber domes. This all is quite time-consuming but all worth it considering that these keyboard assemblies are hard to get in a good quality state nowadays, Threat to see this machine working well again! :9

[@TheRealMentat001]

I'm not surprised by the video capability. The Atari 8-bit video chip (CTIA & GTIA) was developed under the direction of Jay Miner, who was also responsible for the Amiga's original chip-set (OCS) graphics.

[@Artiken1]

On keyboards where the membrane is a double silver, the pads end up with a brown spot. (Oxidized) Dip cotton swab in 99 ipa, shake the excess off, rub gently in circle. On many C64 keyboards or other carbon contact keyboards, the ipa-cotton swab, abrades and turns the shiny (no contact) spots to a fantastic dull (great contact) spot again. The cotton does act as an abrasive, in conjunction with the 99 ipa. I have used the white eraser meant for ink pen erasing. The pink erasers do not work. They worked but were to abrasive for my liking.

[@jasongauthier9818]

Hi Adrian, Best Electronics in San Jose, CA is an operational exclusive Atari Computer Dealer. I bought a new keyboard membrane from him for my 800xl as well as rebuildable power supplies for both the XL and 1050 5.25" drive. He has thousands of parts/components.

[@LeoA2600]

Alas, Best Electronics doesn't. They've had upgraded replacement keyboard membranes made for every Atari keyboard except for the Atari 800 Mitsumi made keyboard. Best estimates that only 1% of the production run utilized this due to its extremely high failure rate and only receives a request for a replacement about once a decade, making producing a replacement obviously not cost effective. Had Adrian not managed to get this going again, likely the only replacement would've been cannibalizing a better keyboard off of a parts machine to swap into this 800.

[@jasongauthier9818]

Ahh thanks for the clarification. I felt lucky to have found them as I actually was able to order an entire keyboard with the upgraded membrane from them, they were great to deal with!

[@LeoA2600]

@@jasongauthier9818 Yeah, Best Electronics is a huge asset for the Atari community and I suspect will prove very useful to Adrian if he continues to dive into these classic Atari machines.

[@brianv2871]

since Adrian works in IT security, i doubt he'll love their "email us your credit card" aspect.... Haha... (Yeah, they sorta do take paypal now for additional cost and restrictions)

[@LeoA2600]

@@brianv2871 One could always use one of those temporary credit cards you can buy at the checkout aisle at places like Walmart, that only has whatever funds you've loaded it up with.

[@axonis2306]

Adrian, would you consider a few videos to show some serious applications of these computers ? Many of us who remember them fondly have memories of moms and dads doing some real work like word processing with them.

[@markholle3450]

When the Atari 400 and 800 came out, I was 15. I wanted the 400 because I thought the keyboard looked cooler. I may have been on to something after watching this video.

[@jokkea492]

great job

[@lorensims4846]

The first keyboard on the Atari 800 felt loose and wobbly, but the late model 800 that I had, like yours, had a very nice keyboard, similar to that on the 1200XL.

[@LMacNeill]

My uncle had an Atari 800 that he bought in '79 or '80, I forget precisely when, as I was only a kid, 9 or 10 years old. I remember playing a game called Star Raiders on it -- really enjoyable.

[@brostenen]

congrats 👍

[@RyanUkAus]

Great to see the original keyboard was saved and not scrapped! Just wondering if anyone knows where / if replacement keys for this machine can be sourced? I am missing a spacebar!

[@Neodra]

I work at recycle center in the computer dept. I found one of these exact machines just thrown in the pile, asked my boss if I could have it and he said I could. Took it home and plugged it in and it worked perfectly, I didn't have to fiddle with it at all. Constructed like a tank, it's missing a few keycaps and I only have pole position for it, at some point I need to decide what to get so I can load software on it.

[@garethr1970]

This is definitely one of the best looking machines of that era. Hard to believe it came out in 1979. Interesting fact: When IBM was looking to enter the personal computing market with the PC, they initially considered buying Atari and remodelling the Atari 800 into the IBM PC! There are images of a design mock-up for this 'IBM PC' - a white machine that is obviously based on the 800 but with subtly different angles to the case. Of course, IBM went a completely different route with their PC but it's interesting to wonder how the home computing market would have been different if they'd instead gone with a modifed Atari 800 as their IBM PC...

[@dodgydruid]

I seem to remember the right cartridge used an assembler package that you could develop games and applications in pure machine code and when the programme had been created you saved the finished package onto your storage medium of choice and I do seem to remember there was a way to get EEPROM cartridges but were uber expensive.

[@scottgfx]

I commented on the previous video that I had bought an 800 on Ebay where the owner bought a new old stock keyboard. The keyboard indeed was indeed brand new and has the square guides with the metal contacts. Those must be out there available for purchase somewhere. The only problem was that something has shrunk, and the keycaps don't stay in place if you turn the machine upside down. So imagine the mess when it was shipped to me! :) Great job Andrew, and maybe we can find a better keyboard for your 800.

[@neilcaldwell870]

Had a similar issue on my alarm keypad at home. I saw a video where you slighty abrasive clean the gold contacts on the PCB, then rub over with IPA. Then the little round rubber bits on the movable membrane section, do the following: Get a soft pencil and rub for a while on a piece of paper (to get a large black graphite shaded area). Then clean 1st with IPA the black rubber round bit and then gently rub it over the graphite shading on your piece of paper (Which is conductive), this sort of coats the black bit with the graphite / lead from the pencil. This seemed to work well on my membrane keypad. Also used the same technique on my cordless phone. Should then last a good few years more.

[@Johnathan_Waters]

Yes, the membranes are separate when new. I have dealt with this exact issue on other devices that use the exact same type of keyboard. My fix is to separate the two membranes, then re-paint the carbon conductive paint onto the rubber pads. Always works perfectly after that...I believe the paint actually physically wears out over time.

[@richardkelsch3640]

POKE 82,0 gets rid of the ridiculous 2 column indent Atari BASIC has on bootup. This allows full 40 column usage. I guess Atari figured the two columns helped with televisions with heavy overscan. As to the membrane. Bradley Coda of "Best Electronics" sells everything Atari, and had purchased Atari's remaining stock and is still selling it. His web sight is horrid, but it's the best place for Atari parts. Note, however, Bradley is quite quirky and must have been who Jerry Seinfeld was talking about as the "Soup Nazi". Whatever you do, don't say anything negative about Bradley (including his horrid web site). Just follow his directions on ordering. It's weird, but he is reliable and secure about it, as well as quick. The one thing the POKEY has over the SID is the POKEY is high fidelity, which means it can generate frequencies from 20-20,000 Hz. The SID has the bandwidth of an AM radio. Granted, the SID have signal shaping, etc like a real synthesizer, but in the end it has a 9KHz max bandwidth. This is the biggest and most noticeable difference between the two chips. Those hearing a SID and POKEY first comment on how "bright" the POKEY sounds and how "warm" a SID sounds. This is why some chip tunes sound better on a POKEY (like Ballblazer's sound track) and some sound better on a SID. It depends on the bandwidth desired. Something simple like the Lucasfilm logo sounds better on a POKEY than it does on a SID, simply because of the triangle note at the end that the SID is incapable of generating. However, to get real high fidelity out of a POKEY, you have to combine two of the sound channels to get one high resolution channel (a POKEY feature). Since there are four standard sound channels for low fidelity sound, the max high fidelity channels available are two. However, you can have two low fidelity channels and one high fidelity channel and get a decent amount of channels. Which is usually how it is typically done.

[@adriansdigitalbasement]

I had checked Best Electronics and has has membranes for the 800XL but not this one. On the other hand, I see SellMyRetro in the UK has the membrane for sale (thanks for another Patron for pointing that out.) It's funny about the indent -- I wondered about that. Interesting tidbit on the Pokey -- I noticed the crispness of the sound, and also it was less noisy overall ... Like the early C64 games, seems like most games didn't do too much with the Pokey (or the SID) but seems like by 84-85 the SID tunes on games were really impressive, while it seems you really have to go to the later games from Poland or demos on the Atari to get some impressive music. I wonder why that is? Was it harder to program the Pokey? Took more CPU time perhaps?

[@fred_derf]

@Richard Kelsch, writes _"I guess Atari figured the two columns helped with televisions with heavy overscan."_ For those people who weren't around back in the day, TVs were really horrid, but nobody knew it. CRT based TVs all used overscan so that the edges of the visible image are clean but there was no standard amount of overscan, so one TV would hide 2% of the image, others would hide 10% (or more). And it was individual set specific, two TVs of the same brand and model could have wildly different overscan. Some would hide more on the left than the right (or vice versa), and more or less on the top and bottom. If you were daring, you could open up the back of the TV and adjust the image to minimize the overscan for your individual TV. TVs back then didn't even have video inputs, they just had RF antenna inputs and if it was a higher-end TV it might have a cable input, but they didn't have Composite or S-Video inputs. Fun fact: early arcade video game (like Pong for instance) used off-the-shelf TVs for displays with the video-in hacked to bypass the RF converter. One of the reasons monitors became so popular was because they were built to better tolerances and produced much better images even though they use the same resolutions (having bespoke video inputs helped a lot to). Once home computers, video games, and VCRs became popular TV manufacturers picked up their game and started making better TVs -- but that happened _after_ the 800 came out.

[@sa3270]

Atari's text field was 8/7 times as wide as those of the Apple II and the Commodore 64, so it was highly likely some characters in the corners would be hidden on many older televisions.

[@richardkelsch3640]

@@fred_derf Atari Basic went through three bug fixes over the period of tine that the 8 bit series was available, which corresponds with essentially the three model changes. They were release A, B and C. Release A was for the 400800, release B was for the XL series, and release C was for the XE series. Release A may have an excuse for the loss of two columns (1970s TVs), but B and C have no excuse, as they were released in the 80s. Also, for someone in his 50s, I don't need to be lectured on "how things were".

[@fred_derf]

@@richardkelsch3640 I wasn't lecturing you, I was adding information to the information you presented for the benefit of others who weren't around at the time. You mentioned overscan, but for a lot of people (say those born this century who have never had TVs that weren't flat panels) would have no idea what overscan was.

[@davidorama6690]

I remember yearning for an Atari computer when I used to hang out at computer stores dreaming of buying - there’s something about the design which makes it as iconic as an Apple ][ as far as I’m concerned. Gee they were great days.

[@wesley00042]

The keyboard and disk/tape access sounds came through the internal speaker, and you could PWM additional sounds through it. It was common to install a toggle switch on the underside to enable/disable the speaker.

[@gamedoutgamer]

The disk IO on the 800 comes through the regular audio channel, not the internal speaker. Love the PWM musics coming out lately but better to hear them on XL/XE machines.

[@wesley00042]

@@gamedoutgamer My bad. It's been a while.

[@gamedoutgamer]

@@wesley00042 No problem! Here's a nice PWM tune made recently kzbin.info/www/bejne/kGGoiICrbpmXfZI

[@kjtroj]

What an amazingly frustrating problem to encounter! Old keyboards are definitely finickey (yes, that was intentional)