Most liked posts in thread: My 800's keyboard is dead

Hi Matt
I've had a brief look at the diagram as well, seems "KR1" Reads all key values via the two 4051's and the control lines to each K0-K2 on one K3-K5 on the other. KR2 only reads "Break", "Ctrl" & "Shift" of which you know "Break" is working suspect the other two will be as well. (uses K5&K6 I think
"KR1" goes from pin 25 of Pokey to pin3 of Z104 and is pulled weakly high by R128 to 5V (47K) worth checking as this is the ONLY common line for the rest of the keys, should see negative pulses if working o.k that of course is not to say its not something else, hope its not POKEY.
" From Lee Avery's Altirra Hardware ref Man"
The Start, Select, Option, and Reset keys do not have key codes associated with them as they are detected differently; Shift and Control keys function as modifier keys.
This is via "KR2"
Scan algorithm
The keyboard scanning hardware consists of a 6-bit counter, a 6-bit latched compare register, and a state machine with four states. One key out of 64 total is checked per cycle at 15KHz, so a full scan takes 4ms that's the "KR1"


Hope this is of some help ....

Just checked my keyboard it's a stackpole
guessing its just waiting to break
wish you luck

 

I finally got back around to working on my 800 again yesterday.

The last time I bothered, several months ago, I had just replaced the sockets for the 4051 IC's as well as brand new 4051's, even though I already had about half a dozen on hand, just in case. After re-assembling the computer in stock configuration, I powered it up and got the "red screen of death." At the time I knew this was merely a bad connection issue with one of the 5 PC boards as it had been powering up to either the memo pad or SpartaDOS X command line depending on if I had it in stock or Incognito configurations (easily swapped out thanks to my new approach of using Dupont connectors on all wires), I just couldn't do anything else since the keyboard didn't work at all except for the break key (and function keys on a different circuit). But, I had grown tired of working on it, and set it aside, even though my trouble-shooting so far only included blindly replacing components instead of testing circuits and components properly.

So yesterday I took her apart and dis-assembled her and re-assembled her in the Incognito configuration since there's only two PC boards to worry about making proper contact. And as I suspected, it was a simple connection issue, she booted up to the SpartaDOS command line. However, the keyboard still doesn't work. But, it just so happens that I already have a back-up plan in mind, which will get me a working 800 while verifying for sure that the non-working keyboard IS a motherboard issue and not the keyboard itself.

What? You want to know my plan? OK, it's a plan that helps with more than one project as well. The other project that will benefit, which in turn gave me the excuse to take the easy way out, for now, if it is a motherboard issue for the keyboard, is my robot project. I originally planned on using a 400 for my robot's brain, but with my current situation with my 800, I decided I would give my robot an 800, but I'll still use a 400 keyboard with it. I decided to buy another 800 motherboard. I had one on my watch list for several weeks, from MyAtari, for $40 dollars. Which by the way is a good deal no matter what, these days, but it's also a way to still get extra POKEY's on the cheap, instead of buying just a POKEY chip for the going rate of about $65 or more these days (which is why I bought a Quad POKEYmax since it's less money!). And if you think buying $40 800 motherboards just for POKEY chips is a pretty good idea, you better jump on it because there's no telling when MyAtari will figure out they could sell the POKEY chips from these mobo's separately and still sell the mobo's for the same price sans POKEY! And don't think they won't start, others already have!

Which brings me to my even better deal I got on my 800 motherboard from another seller on eBay for a mere $15! But you probably just guessed that it's sans POKEY. I of course also bought a PSU board for it which was the same price. Anyway, these items just arrived in the post yesterday, which is why I started working on my 800 again last night. I already made sure that my 800's PSU board was, in fact, working properly as using the new one changed nothing with the condition of my 800. If the same happens with the new motherboard when I plug the keyboard into it, then I'll know straight away that it's the keyboard and not the motherboard. There's less than a dozen wires that I'd have to solder to the new mobo to move the Incognito over to it, so that's not a big deal once I'm 100% sure the keyboard is or isn't the problem.

After all is said and done, I'll have a working Incognito 800 soon, unless I have to wait on a keyboard, and eventually I'll properly trouble shoot the original 800 mobo in time to go into my Bender 800 robot.

 

Yay, no Red Screen .. All we need now is a working keyboard one way or another ? Are you working on this now Matt, or is this for another day ?

 

I will be working on it again this evening. First I'll start by adding the Pokey chip and a spare CPU board and OS and 16K ram board to the new motherboard, plug in the keyboard and power her up to see if the keyboard works or not. If it works, then I will install the Incognito into the new motherboard this evening. If the keyboard doesn't work, then it's safe to assume that it's the keyboard and not my original motherboard, and I won't have to do anything except start adding more upgrades and moving on with the project while I wait on getting a new keyboard. After one more attempt of finding any issue with the original keyboard. I'll have to wait until the end of the month to get one. Either way, the project can move forward after this evening.

 

I did just notice that my new motherboard has a male keyboard connector on it instead of the female connector on my original board, so I'll have to temporarily rig it up for testing, if it does work, I think it will be easier to attach a female connector onto the end of my keyboard's ribbon cable, since it's the Hi-tek keyboard with the bare wires that plug into the female connector, so instead of desoldering and soldering in a connector on the new motherboard I can solder a connector onto the keyboard's ribbon cable. I happen to have some break-away connectors on hand that I can use that should work, but if they don't match up I'll just solder Dupont connectors to the end of the ribbon cable and plug each one in individually to the motherboard's male connector. Then I'll have to order more Dupont connectors for all the other upgrades and mods...

 

Yeah, I ended up not working on the 800 last night, because I found out my favorite football team was being televised in my area. I usually just listen to the radio broadcast over the internet, since the Chicago Bears aren't in my broadcast area, except with nationally televised games like this one a couple times a season. Or, I have to pay $350 a season for streaming NFL Sunday Ticket to see them. It was on until 10:30 pm and I was too tired afterward. I did at least take apart the 800 again, before I went to bed, because I still need to use the CPU board out of it for testing the new motherboard, even though I have OS and memory boards at hand, my other CPU boards have bad color pots. And I prefer testing with the mobo properly grounded to the chassis.

So I didn't want to miss watching them with my full attention. Today I was busy all day up until about 9:30 pm this evening, my time. I think I will stay up long enough to at least test out the keyboard on the new motherboard and see what happens, but the project continuation, for the most part, is delayed until tomorrow (Saturday) and Sunday, and no distractions at all since my Bears won't even be on the radio since they already played for the week.

 

Well it's some relief to know its all working, and now you have a working Atari 800 to play with
I'll look out for any posts on you blog.

 

EDIT: Update, you can ignore the rest below, I swapped out the new PSU board I have been using for the old one I repaired before, and my new mobo with Incognito booted!! Yay!!!

One thing I can try, which I've been assuming isn't the problem is the new PSU board I got with the new mother board. I've been using it to power the new motherboard, since it successfully powered up in stock condition. Even though I had repaired the original, which seems fine now, earlier this year. It could be a lack of power from bad caps that just gave out over the last 24 hours from the shock of being used after being on a shelf for 4 decades. I'll go ahead and try my repaired PSU board before I go to bed, on the new board with the Incognito still installed. I'm not going to get into checking for proper voltages on it until tomorrow, and not at all if swapping PSU's doesn't change anything, because both were used to successfully power up their respective boards to memo pad or SDX command line within the last couple of days.

 

A final update on my computer situation. After using the 800 for a few short minutes, the keyboard suddenly went completely dead on my on my new motherboard with Incognito. I guess I must have just been jarred & installed in the right way that the circuits were working until my activity on it broke contact again somewhere. So I have come full circle, thinking I broke my fragile keyboard while replacing plungers and soldering cold solder points, going over it again and again and then leading myself to the conclusion that it wasn't the keyboard, but something wrong on the motherboard.

Well it appears that both boards with or without Incognito installed have been in perfecting working order all along, and that's why I could not solve the issue on my original motherboard, as there wasn't one, ever. So I definitely need to look for a new keyboard, preferably a Mitsumi, like my 1200XL, as I'm tired of the problems the Hi-tek mechanical keyboard has caused me. But I'll settle for a working Hi-tek and I can use my Hi-tek for spare plungers and key caps. So keep your eyes out for either one, a complete and work Mitsumi, or a Hi-tek, as long as it works, can have missing keys or some broken plungers since I have spare parts.

In the mean time, I will continue with upgrading my 800 as planned, the next step installing the Pokeymax and audio/video outs, and also a second SIO. I'll wait on some of the more involved upgrades after I get a replacement keyboard, but most of this is just running lines from stock SIO and the monitor jack ports to new ports. The Pokeymax is just L/R RCA or phono out too after plugging it in and soldering two wires. Finding a new keyboard is top priority for me, asap, as long as I can afford it, I may try to bypass traces and repair this keyboard in the meantime, but I'd rather just move on as fast as I can with a replacement. I think this one is just too old and fragile with age and use and more of the same will just keep happening to it. At least Mitsumi keyboard have a replacement Mylar available from MyAtari.

Of course, as I said before, this thread was mainly about the keyboard and still is now, and updates and pictures of my upgrades will be in my hardware hacking blog.

 

I was so determined I did go over the keyboard's circuit again last night touching up every solder point and tracing the circuit traces with a magnifying glass and it all looks good, but just won't work. I suspect it's probably a broken jumper wire in between the circuit board and the keys, which means I completely desolder and rebuild it all, or I try to follow the circuits with a best guess as to where the jumpers all are and go and install my own jumper wires in those spots on the circuit side of the board. Maybe that will fix it.

As I said before, this is such a simple design, it's all circuits and jumpers, there are no IC's or any other components involved, it's shocking that I could have such trouble with it. The original ribbon cable for it looks solid too, it's the clear plastic and I can see every wire running the length of it and can't detect any breaks, but I think I might try swapping it out too.

The only sign of life out of the keyboard is if I have the ribbon connector barely plugged into the motherboard and wiggle it a bit some characters started "typing" themselves on screen and the space bar circuit would move the cursor, but as soon as I plug it in snuggly nothing happens at all, except one time after a reboot the space bar circuit was "stuck" and moved the cursor even though the space bar itself is not engaged at all. But for now I'm setting it aside and get my audio/video mods done on it at least.

Right now the only 800 keyboards available on ebay are the infamous Stackpole versions that MyAtari is shilling for $100 each, which I will never pay.

 

Well, I spent about an hour working on the keyboard, and only made it worse where now the system crashes when I plug it in. So, I'm going to have to desolder and completely disassemble it and rebuild it from scratch, while hoping I find a Mitsumi keyboard for a reasonable price in the mean time so I don't have to depend on my success in a rebuild. But I started on more upgrades for the 800 which is going well so far. Pictures and explanations will be in my hardware blog soon, maybe by the time this has been read.

 

Hi Matt
How about using a TK-II with a PS/2 keyboard as a temporary solution, that way it's still usable and you can still check each of your upgrades.

I can confirm it fits in an 800, and will even fit with a PokeyMAX board on top, as I've just checked.
I know it's not original but it may help you, only just finished putting it together, and I've not programmed the PIC chip yet just about to. If you would like it, let me know and drop me your Home address on a PM and I'll get it sent out to you.
I am however away for a few days tomorrow onward so best replie as soon as; so I can get Pam to send it in the morning.

 

Fair enough fella get some zzZZZZZZ's
It will only work with a PS/2 keyboard, and I included the PS/2 socket and Wiring harness needed to get it running. some are programming pins for the micro, plus additional pins if you wanted to use the keyboard as a joystick, Plus there are some other functions such as non locking toggling of pins, to control things directly from a PC keyboard
if you get a chance have a look here.
https://ataribits.weebly.com/tk-ii.html
It's about half way down the Pokey Piggyback. It has software version 2.5J but I can change that to 2.4 easily. Just let me know if you want to give it a try sometime, as PS/2 keyboards tend to be really cheap to buy, P.S I'm going to try a USB version at some point, this is writtedn on an AVR microprocessor rather than PIC.

 

I'm back after a nap for a few hours. I do think I might have one PS/2 keyboard left, after having some time to sleep on it. Or it could be a PS/1 keyboard with the larger plug, but if that's the case I do have an adapter. Actually, I'll be back in a minute, going to go check on that keyboard, it's still in storage, but that's organized now...

...O.k., I'm back, and I do have a PS/2 keyboard...it's made by Digital. It needs a good cleaning, but I bet it works. I can try it out on my PC which still has PS/2 mouse & keyboard inputs. The last of what was once a plethora...



I'll PM my address in case there is still time...

 

My keyboard is ALIVE!

Yep, it is, and of course it was a very simple issue and fix, but it sabotaged the works! My bane for months. Sorry @Graham , to have you send off the TK-II to me that I don't need before it even arrives! I'll send it back to you in short order. And thank you.

So, it turns out that it was a short in the space bar brush mechanism making it act as if the space bar were depressed constantly, and my guess as to why it froze the entire keyboard instead of just moving the cursor along is that being depressed from power-up and through the boot-strapping process that it just didn't react like the space bar being held down, but just froze the keyboard.

It was one of the teeth/legs of the small metal brushes under the key cap that make contact when depressed. It had broken off the brush and jammed itself in between where it shorted the key. The only reason I found it was because I started to disassemble the entire keyboard, removing the caps first, then I turned it over and started desoldering the space bar. Then I turned it over to look down in the space bar's key housing to see if the brushes could be removed with tweezers (No, it's all one piece), and that's when I noticed. So I removed the offending object and tested the keyboard and it works!

So, if you have been following my hardware hacking blog, you know I've completed all my upgrades and mods for the 800, for now. I'll enjoy it for a while, while I work on my 1200XL. Once the 1200XL is fixed, by then I should have the Turbo Freezer, multi-PIA board and maybe even the Sophia 2 in my possession and do another round of upgrades to the 800. But not until I have a back-up Atari working will I ever even do the simplist mods on either machine in the future.

 

That's Great news Matt, I'm pleased you persevered with the keyboard, and just one of those things as to the fault.
Why don’t you try out the TK-II
I don’t expect you to use it over and above any standard keyboard, however for those few times doing repairs, the AKI I’ve used a few times, that and a board from Tf_hh that plugs into where the ribbon cables on 65/130XE. 600/800XL’s however I think its a bit ‘thick’ so if Pokey is in a socket I use one of these, rather than damage the connector on the Mainboard.

Seriously no need to return, I made four others J

 

Glad you have been busy, I've just been updating the 800XL, 1200XL decoder boards in KiCad, I'm guessing that with no new post either things not worked out or you have ended up busy without time to continue with it.
Hope you get some success / time over the weekend.

 

HeHe Well that's dedication to your team. It's a bit like that for me with Fornula 1 racing on this weekend, so I tend to veg out and watch all the goings on that are televised.
On another note, I can't believe the service I seem to be getting for items shipped from over sea's Wednesday evening my time 17:29 placed order online to Digi-Key arrived by 19AM two days later..
PCB order Shipped on the 8th from Hong Kong due to be delivered to day (originally showed 13th.) as out for delivery.
The World is a mad mad place but It seems the delivery services have gotten better than ever before .. thats UPS & DHL
Anyway I hope it all works out over this weeked so you have a working 800.

 

Hi Matt
That's so disappointing but at least you know its the Keyboard, in your case I suspect that it's all down to one or two wires that need another look. I can only guess at your frustration. I still think the original keyboard can be fixed even if re wiring all the key switches

 

Brilliant, You have your MoJo back..
I had a moment last night or should I say early hours of this morning But I think it was just tiredness, I just couldn't work out why the CPC I was working on worked one moment and not the next, turned out it was the Main PSU connection to the Video harness before it plugged into the back of the CPC, if I rotated the plug it would work a bit further and it failed. Strangely Most of the time you could see a voltage, but as soon as loaded couldn't provide any current..

 

GREAT WORK, chaps - well in, Matt, solving the short and super support from Graham there. Nice one, fellas. Onwards and upwards...

 

Well thank you very much @Graham , I will keep it and use it for "emergencies" if any more of my Atari keyboards go bad.

 

@M.D.Baker