12v line in the keyboard and then regulating locally will make the 5v supply at the kbd cleaner with no noise picked up along the cable to the mother board. This decision was likely made due to the sensitivity of the capacitive sense circuitry and the routing of the coiled kbd cable near the CRT and PSU.
That's quite possibly the best answer I've heard. I didn't emphasis it, but it really doesn't take much capacitance to set off a key press, and I had to do a fair number of adjustments to get it to work, so this might be actually why if the cable run at 5v introduced too much noise.
That is debatable and would only make sense if also the data transfer is happening at the greater differential voltage of +12V to GND. Which is NOT the case[1]. A near decoupling capacitor and the at the time usual ferrite-EMI-supression filters at the cable would be sufficient. The evaluation of the capacitive keys happens locally and by the way is a possibility to completely avoid the usual problem "antenna keyboard" (as an electromagnetic receiver) (capacitive!). Separate voltage regulators are used where a correspondingly high current might disturb the supply voltage and following the signal integrity. But that is not the case here with a keyboard with
The one Compaq I bought didn't come with a keyboard (I wanted the unit just to use the CRT and floppies in another project). Now I'm really glad the keyboard was missing!
UPDATE: The Retro5 disk drive belts didn't work fit properly, despite being close. I'm looking for other solutions. EDIT: Ok, they sorta worked. As it turns out, installing them is very difficult, but the drivers are still kinda kaput.
@@Kardor 8-bit guy tried making his own when he reworked his Compaq portable. He ended up going with texElec, but perhaps you might take a look and see if you can improve on his efforts....but yea...$29? I'll probably bite that bullet when the time comes too. I don't have the knowhow, and it would probably cost more the $29, but I'd love to have a mechanical keyboard replacement that would drop into the old keyboard case for this.
It can't be worse then the membrane keys uses in a lot of 80s microcomputers right? Because I've used enough of those for one lifetime thank you very much.
Honestly, I'd argue those are better primarily because you not expecting something like a Model F experience or similar. This looks like a a normal PC keyboard, and should have things like key travel ... but it doesn't ...
It wasn't just Compaq keyboards. It was any computer that used a Keytronics type capacative layout, Apple Lisa, Tandy Model II,12,16,6000 Sun type 4. Just to name a few.
Not gonna lie, I actually like my Compaq Portable keyboards. I have no real complaints. Sure, it’s a little time consuming replacing those pads, but that’s all part of the fun to me!
There many rubber belts in most of retro FDD/CD drives that usually become slippery due to rubber oxidation. I managed to work out (after lots of testing) that a solution used to maintain rubber V-belts in a car works fine also for belts in legacy drives. It actually make rubber more sticky and increases friction, which is exactly what we need. I use a solution in a form f sprawy made by BOLL, but others shall work as well. Just dismount a belt from a drive and give it a good wash in a solution (I use small glass jar to fill the bottom with solution up to the point where all the belt is covered) and leave it there for 1-2 hours.
@@NCommander sorry, I meant 'form of spray'. I did not notice that this got autocorrected. It is this one: www.amazon.de/-/en/gp/aw/d/B07NPYGLCK/ref=cm_cr_arp_mb_bdcrb_top?ie=UTF8 but I think any of those vbelt spray will do a fine job.
@@86smoke hrm, it seems Boll isn't sold int he United States, and I'm having trouble finding an equivelent product, so I dunno how much help this will be. I'll keep this in mind though. It sounds like you just put it in a container, and soaked it though?
@@NCommander It looks like in the US this stuff is called 'belt dressing', 'belt grip spray' or 'belt conditioner', but it is not as popular as it is in Europe. I found out that Wurth USA should be selling it locally. Yes, I put rubber belt in a small container, giving it a good flush, then close a lid and leave it for some time. After it dried a bit (but not completely) it is good to go.
Made same bad decisions (not wearing mask nor test contact with fingers). Did the entire replacement of foam/foil and still stuck at 301. Will check cable for voltage and continuity next weekend.
The case isn't cracked, because I took my own Compaq apart and the plastic cover is made from upper and lower part. (you need to unscrew the carry handle) After the whole disassembly, there will be left just the metal frame (it is riveted)
@@NCommander Oh, If you saw it cracking, then the plastic is probably broken. But in the video, it looks like, it is right at the point of connection between the upper and lower case part. I also have a gap there on my Compaq, but there is a little stud sticking out from the lower to the upper case for correct alignment of the parts. The stud might be broken, so that's why the bottom part is slightly offset from the top part. Anyhow, good luck on repairing the Compaq.
@@NCommander solis123 is correct. That is the seam where the two case halves come together. You may have thought you saw it crack, but that is two separate pieces of plastic. I’ve owned and repaired many of these, so I can confirm. Definitely don’t glue it, or you’ll be in for a world of hurt if you want to take the plastic shell off ever.
NCommander, I am working on restoring a Keytronics A65-02428-001 Capacitive keyboard. It looks like the same manufacturer was used in the Compaq and would like to know if the board has a couple of EXAR I.C.'s that do the keyboard scanning. If so, could you let me know what their part numbers are?
From what I've learned since, there were multiple revs of the Compaq portable PCB (I think I said it in the video), so I'm not sure how much any info I can provid ewill help since it was clearly reworked multiple times.
@@NCommander Actually, your video helped me to identify an I.C. that blew on my Visual 50 keyboard. I just wanted to verify that the chips on the board you showed in your video is the correct one I need to fix mine. After hard searching I was able to find an XR22-950-3B available through eBay. The other one should be an XR22-908-03.
Loved watching this, it gave me a great sense of nostalgia, taking me back 30+ years. The boss dropped one of these on my desk when he had switched to a Compaq III "Lunchbox", saying "Here's something you can make use of instead of that old Commodore PET". - At least the PET was trouble-free! Power supply failures (x2), keypad disintegration, Card (hard) drive failures. The PSUs were an absolute pig to get out (and replace) as ½ the machine had to be dismantled to release it, but it did give me an introduction to DOS and Lotus 123, though I did think the Commodore basic was better to use than the Compaq PC basic.
I would guess that the keyboard PCB was used on other machines that had 12V keyboard power. It's a very odd voltage to use for a keyboard though... I guess if the cable was long enough it might help with losses, but the keyboard shouldn't draw much current.
@@NCommander the data lines have no load though, maybe the port is a Compaq thing that can connect higher power stuff. Tape reader maybe. It's a pretty wild theory though. Might do some research...
I'm thinking it could also be noise mitigation, assuming the data lines are stepped up to 0-12V as well. The bigger the threshold on a voltage-signaled line, the more noise it takes to disturb it. Given the cramped conditions of the Portable, and the proximity of the CRT's (relatively) high-emission electronics, it seems a reasonable concern to me.
Well regarding the keyboard, IBM clicky keyboards are high quality but annoy the F out of everyone in the room. I sort of like this keyboard. Its the spongy keyboards of the time which were quiet and fast rather than CLUNKITY.
I have a Compaq Portable that's falling apart unfortunately. Trying to find a tech youtuber that's local to give it to. Don't want to ship this heavy beast because it's too weak
oh chyros hates the foam and foil keyboards even more than you do, they're truly the work of the devil edit: why is the output of the portable so noisy at times? is it just a bad composite output or is it not properly shielded? also, the keycaps seem to be doubleshots. they're very expensive to produce, but they last pretty much forever, as the lettering is separate from the surface. sucks to see that they're really flimsy though
Chyros is right to hate the foam. I legitimately have no idea what inspired Compaq to use this horridness. The only semi-fessiable answer I can come up with is weight, since buckling springs and the like are heavy.. As for the composite, it's likely a combination of old capacitors, and line noise. It's gotten considerably better the more I ran the system (and I already blew a cap on the VDU). I actually did color correction to remove some of the noise, but it's not great. I also suspect some of it is being introduced by the Retrotink.
@@Kardor I actually haven't done anything with the Portable at this time. I'm fairly burned out on it due to stuff that happened behind the scenes while I was filming this. The relatively low uptake was just salt in the wound :/
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12v line in the keyboard and then regulating locally will make the 5v supply at the kbd cleaner with no noise picked up along the cable to the mother board. This decision was likely made due to the sensitivity of the capacitive sense circuitry and the routing of the coiled kbd cable near the CRT and PSU.
That's quite possibly the best answer I've heard. I didn't emphasis it, but it really doesn't take much capacitance to set off a key press, and I had to do a fair number of adjustments to get it to work, so this might be actually why if the cable run at 5v introduced too much noise.
That is debatable and would only make sense if also the data transfer is happening at the greater differential voltage of +12V to GND. Which is NOT the case[1]. A near decoupling capacitor and the at the time usual ferrite-EMI-supression filters at the cable would be sufficient. The evaluation of the capacitive keys happens locally and by the way is a possibility to completely avoid the usual problem "antenna keyboard" (as an electromagnetic receiver) (capacitive!). Separate voltage regulators are used where a correspondingly high current might disturb the supply voltage and following the signal integrity. But that is not the case here with a keyboard with
The one Compaq I bought didn't come with a keyboard (I wanted the unit just to use the CRT and floppies in another project). Now I'm really glad the keyboard was missing!
"The longer I run it the better the composite output got."
Sounds like a failing cap to me.
Already had a cap explode on the VDU, but I don't have a soldering gun. Given its tantum caps, I'm OK-ish leaving it "as is"
UPDATE: The Retro5 disk drive belts didn't work fit properly, despite being close. I'm looking for other solutions.
EDIT: Ok, they sorta worked. As it turns out, installing them is very difficult, but the drivers are still kinda kaput.
The only update we expect from you now is part three. Pleeeeaaaaseeeee.
Also is there a cheaper alternative to these foam thingies?
@@Kardor $29 for a full set really isn't that bad. I tried laminating my own and it didn't work out.
@@Kardor 8-bit guy tried making his own when he reworked his Compaq portable. He ended up going with texElec, but perhaps you might take a look and see if you can improve on his efforts....but yea...$29? I'll probably bite that bullet when the time comes too. I don't have the knowhow, and it would probably cost more the $29, but I'd love to have a mechanical keyboard replacement that would drop into the old keyboard case for this.
It can't be worse then the membrane keys uses in a lot of 80s microcomputers right? Because I've used enough of those for one lifetime thank you very much.
Honestly, I'd argue those are better primarily because you not expecting something like a Model F experience or similar. This looks like a a normal PC keyboard, and should have things like key travel ... but it doesn't ...
4:18 Did you get system error 418 as well? This is the error when HUMOR.SYS doesn't load correctly on boot. 😹🙀
Ah. Good to see this again.
Foam and foil.
The bane of our existence.
15:10 maybe that change was made so they don't get sued by IBM that they copied their design
I didn't think the keyboard could possibly be as bad as you said. Then you did the typing demonstration.
All foam and foil keyboards should be shot.
There are worse things. Not many, but there are...
@@NCommander yeah like mosquitos... In the night... When you are trying to sleep. D:
It wasn't just Compaq keyboards. It was any computer that used a Keytronics type capacative layout, Apple Lisa, Tandy Model II,12,16,6000
Sun type 4. Just to name a few.
Not gonna lie, I actually like my Compaq Portable keyboards. I have no real complaints. Sure, it’s a little time consuming replacing those pads, but that’s all part of the fun to me!
There many rubber belts in most of retro FDD/CD drives that usually become slippery due to rubber oxidation. I managed to work out (after lots of testing) that a solution used to maintain rubber V-belts in a car works fine also for belts in legacy drives. It actually make rubber more sticky and increases friction, which is exactly what we need. I use a solution in a form f sprawy made by BOLL, but others shall work as well. Just dismount a belt from a drive and give it a good wash in a solution (I use small glass jar to fill the bottom with solution up to the point where all the belt is covered) and leave it there for 1-2 hours.
I'm not finding this form f spray. can you post more instructions/stuff I need?
@@NCommander sorry, I meant 'form of spray'. I did not notice that this got autocorrected. It is this one: www.amazon.de/-/en/gp/aw/d/B07NPYGLCK/ref=cm_cr_arp_mb_bdcrb_top?ie=UTF8 but I think any of those vbelt spray will do a fine job.
@@86smoke hrm, it seems Boll isn't sold int he United States, and I'm having trouble finding an equivelent product, so I dunno how much help this will be. I'll keep this in mind though.
It sounds like you just put it in a container, and soaked it though?
@@NCommander It looks like in the US this stuff is called 'belt dressing', 'belt grip spray' or 'belt conditioner', but it is not as popular as it is in Europe. I found out that Wurth USA should be selling it locally.
Yes, I put rubber belt in a small container, giving it a good flush, then close a lid and leave it for some time. After it dried a bit (but not completely) it is good to go.
@@86smoke I ordered some, we'll see if it works.
Made same bad decisions (not wearing mask nor test contact with fingers). Did the entire replacement of foam/foil and still stuck at 301. Will check cable for voltage and continuity next weekend.
Bro, i just stumbled across your channel. I'm just fascinated with all your hard work and knowledge.
A lot of this stuff glosses over my head because I am very much, well. Zoom, zoom. Channel is a treasure.
The case isn't cracked, because I took my own Compaq apart and the plastic cover is made from upper and lower part. (you need to unscrew the carry handle) After the whole disassembly, there will be left just the metal frame (it is riveted)
It actually cracked visibly (I saw it crack in front of my eyes), and I can see from my old footage that there are cracks that shouldn't be there.
@@NCommander Oh, If you saw it cracking, then the plastic is probably broken. But in the video, it looks like, it is right at the point of connection between the upper and lower case part. I also have a gap there on my Compaq, but there is a little stud sticking out from the lower to the upper case for correct alignment of the parts. The stud might be broken, so that's why the bottom part is slightly offset from the top part. Anyhow, good luck on repairing the Compaq.
@@NCommander solis123 is correct. That is the seam where the two case halves come together. You may have thought you saw it crack, but that is two separate pieces of plastic. I’ve owned and repaired many of these, so I can confirm. Definitely don’t glue it, or you’ll be in for a world of hurt if you want to take the plastic shell off ever.
When I used to refurbish used PCs for resale I used a spray on Ajax industrial product to clean the cases. Usually made quick work of it.
Well done. The keyboard looks beautiful, I like its look very much.
NCommander, I am working on restoring a Keytronics A65-02428-001 Capacitive keyboard. It looks like the same manufacturer was used in the Compaq and would like to know if the board has a couple of EXAR I.C.'s that do the keyboard scanning. If so, could you let me know what their part numbers are?
From what I've learned since, there were multiple revs of the Compaq portable PCB (I think I said it in the video), so I'm not sure how much any info I can provid ewill help since it was clearly reworked multiple times.
@@NCommander Actually, your video helped me to identify an I.C. that blew on my Visual 50 keyboard. I just wanted to verify that the chips on the board you showed in your video is the correct one I need to fix mine. After hard searching I was able to find an XR22-950-3B available through eBay. The other one should be an XR22-908-03.
Loved watching this, it gave me a great sense of nostalgia, taking me back 30+ years. The boss dropped one of these on my desk when he had switched to a Compaq III "Lunchbox", saying "Here's something you can make use of instead of that old Commodore PET". - At least the PET was trouble-free! Power supply failures (x2), keypad disintegration, Card (hard) drive failures. The PSUs were an absolute pig to get out (and replace) as ½ the machine had to be dismantled to release it, but it did give me an introduction to DOS and Lotus 123, though I did think the Commodore basic was better to use than the Compaq PC basic.
I would guess that the keyboard PCB was used on other machines that had 12V keyboard power. It's a very odd voltage to use for a keyboard though... I guess if the cable was long enough it might help with losses, but the keyboard shouldn't draw much current.
That was the best theory I could come up with but the cord isn't that long, and the data lines are signaling at 5v just fine at that distance
@@NCommander the data lines have no load though, maybe the port is a Compaq thing that can connect higher power stuff. Tape reader maybe. It's a pretty wild theory though. Might do some research...
I'm thinking it could also be noise mitigation, assuming the data lines are stepped up to 0-12V as well. The bigger the threshold on a voltage-signaled line, the more noise it takes to disturb it. Given the cramped conditions of the Portable, and the proximity of the CRT's (relatively) high-emission electronics, it seems a reasonable concern to me.
@@EdPenwell Could be, 12V signalling for RS232 was common at the time and suitable driver chips were readily available.
Wow that keyboard sounds aweful. Like the most unsatisfying mechanical keyboard in the universe.
Great video! Keep posting the progress!
I never understood why early keyboards had those skinny enter and numpad + type keys. Were they just trying to make life difficult for people typing?
Skinny enter is normal for US keyboards, vs ISO enter seen in the rest of the world
no the Compaq looks more like an ISO enter.
honestly, the puns weren't bad. they were HILARIOUS...
Well regarding the keyboard, IBM clicky keyboards are high quality but annoy the F out of everyone in the room. I sort of like this keyboard. Its the spongy keyboards of the time which were quiet and fast rather than CLUNKITY.
Can't wait to see this at the end!
You had me with the first one, but I agree with the boos, the second one was reaching too far.
So that's what this BASIC piece of code was for.
It's amazing how much effort was put in for something so horrid ;.;
In my Job, I has to deal with 8 such keyboards.... Its a holy christ mess of hell.
I have a Compaq Portable that's falling apart unfortunately. Trying to find a tech youtuber that's local to give it to. Don't want to ship this heavy beast because it's too weak
The keyboard is like 104 styluses on a touchscreen
It works the same way.
I found myself at the interesting part of youtube. :)
You got an abbo from me
At least it has rigid keycaps.
"rigid" is relative :/
oh chyros hates the foam and foil keyboards even more than you do, they're truly the work of the devil
edit: why is the output of the portable so noisy at times? is it just a bad composite output or is it not properly shielded?
also, the keycaps seem to be doubleshots. they're very expensive to produce, but they last pretty much forever, as the lettering is separate from the surface. sucks to see that they're really flimsy though
Chyros is right to hate the foam. I legitimately have no idea what inspired Compaq to use this horridness. The only semi-fessiable answer I can come up with is weight, since buckling springs and the like are heavy..
As for the composite, it's likely a combination of old capacitors, and line noise. It's gotten considerably better the more I ran the system (and I already blew a cap on the VDU). I actually did color correction to remove some of the noise, but it's not great. I also suspect some of it is being introduced by the Retrotink.
Who?
@@videocommenter235 th-cam.com/users/Chyrosran22
literally who?
Woot
Huge space-bar all the other keys tiny...
Pretty standard for XT-style keyboard layouts ...
@@NCommander yea I know but I like the inconsistency...
@@mrcrackerist Well, that's a faiir :)
No! Don't stop with the puns!
If you need to put thermal paste in your keyboard, it is a bad keyboard.
hot board is hot ...
3:18 Among us? Sus
There's one foam and foil keyboard among us ...
SUS
@@Kardor There's one Foil and Foil Among Us ...
@@NCommander There is one NCommander who doesnt upload part 3 among us 😡😡😡😡😡😡
@@Kardor I actually haven't done anything with the Portable at this time. I'm fairly burned out on it due to stuff that happened behind the scenes while I was filming this.
The relatively low uptake was just salt in the wound :/
i feel its a proprietary feature LOL
someone needs to make a modern ish keyboard and ditch the foam