Unboxing and repairing the 80s NABU PC that failed. Let's find out what all the fuss is about.

I got a NOS NABU Personal Computer and it's broken!
Let's also take a close look at that marvelous keyboard :)
--------------------------------------------------------------------------------------
Tools I regularly use
DeoxIT D5 Contact Cleaner
Hanstar 861DW Rework Station
Pro'sKit SS-331 Desoldering Station
UNI-T UT61E Auto Ranging Multimeter
UNI-T UT890D Manual Ranging Multimeter
MESR-100 mk2 ESR meeter
PINECIL Soldering Iron
TS-100 Soldering Iron
AMTECH NC-559-ASM Flux
PinePowerPSU
TL866 II Plus Programmer
Tektronix 2246A 100 MHz four-channel analog scope
MaAnt Grinding Pen
Multicore 60/40. 0.38mm and 0.5mm solder
--------------------------------------------------------------------------------------
Now on patreon.com/Epictronics
Join me on Twitter: / epictronics1
Music by Karl Casey @ White Bat Audio

[@leo.binkowski]

Too bad you didn't make it to the games this time, but thanks for the mention!

[@Epictronics1]

Hi Leo, It's really cool that you are helping us to get these NABUs up and running. We're having a good time :)

[@anthonyblacker8471]

Just the thought of the smell of brand new electronics from the 1980s really tickles my fancy. I am 45 years old and this was my childhood, it was amazing growing up as a young boy in the 1980s, both my parents were technologically inclined and we had a PC when XT was the home computer, we had and original Atari 2600, all the toys back in the early 80s. What a great time to have grown up! Thank you for opening that box for us, I can actually smell exactly the scent you are describing. Great! edit: oh my what an absolute SHIT design on the power supply fan attaching to the case. That fan is absolute overkill, the turbine fan is just crazy the quality.. Amazing..

[@djdoo]

For some reason I liked more the LCD monitor over that hi end hi fi looking computer! It looked slicker, thin and elegant. The whole machine looks modern and high quality, great video, keep up, kisses from Greece!

[@Epictronics1]

Hello Greece! Thank you :) I've been to Korfu ones, it was awesome. Yeah, with that IBM display on top, it looks like a modern PC! Quite remarkable for a PC designed in the early 80s!

[@MetalJesusRocks]

It’s a really nice looking computer! I saw one of these for the first time at the RetroGameCon in Syracuse, NY a few weeks ago. Pretty cool stuff!

[@Epictronics1]

I have a repair video lined up!

[@chuizune]

Man that PC looks so good with the IBM LCD. Looks timeless. Great video!

[@Epictronics1]

Totally agree, thanks :)

[@chaoticsystem2211]

i'd totally hack some random sleeper device into this case :D

[@notneb82]

How lucky to have that monitor on hand that goes so well with the Nabu. A perfect match and looks right at home on top of the computer.

[@Epictronics1]

Yeah, they look perfect together. I had to put a piece of packing foam under the display to make it fit on top of the NABU but it works ok and looks awesome :)

[@ncot_tech]

That startup noise isn't a stuck fan, you've just bought the world's first prototype computer with a petrol engine. Once it revs up to full speed it'll be fine.

[@50shadesofbeige88]

Wow, what a fantastic fan!

[@Epictronics1]

I wonder who was in charge of sourcing components for these NABUs. Probably someone from a different industry, where quality was of a higher priority than cost

[@waytostoned]

Waiting on my NABU to ship... can't wait!

[@Epictronics1]

enjoy :)

[@xianox8]

Never heard of it! Thanks for sharing.

[@Epictronics1]

Well, then welcome to the new hype in the retro world : ) It's actually pretty cool. And that kb is fantastic!

[@50shadesofbeige88]

Model F will always be the "King of Ping" in my opinion. I'll never forget the sound those keys make. I'm still searching for one at the right price.

[@Epictronics1]

Yeah, that comparison was a bit silly and playful :) The model F is in a completely different league than the NABU or Apple kb. I hope you'll find one, they truly are a treat

[@the_kombinator]

I sold one years ago for like $70 CAD.

[@Epictronics1]

@@the_kombinator ooch, that's gotta hurt :/

[@vhfgamer]

That fan is surprisingly familiar to me. I've seen those kinds of fans on the back of some Japanese amateur radios from the 70s. For example... the Yaesu FT 101. It's an AC mains powered metal fan, drawing heat out of the tube based finals of the radio. They're absolute beasts! I'm very surprised to find one of those fans in an 80s computer.

[@Epictronics1]

Yeah, they sure are! I wonder what they were originally designed for. What application requires a dead silent metal fan, at a presumably high cost

[@vhfgamer]

@@Epictronics1 It could be military surplus.

[@SiaVids]

A quality high airflow slow running fan is so much better than the loud high RPM equivalents that we get these days.

[@Epictronics1]

totally agree

[@Mike_Neukam]

Your serial cable pinout is correct, but you should be using one twisted pair for transmit and another twisted pair for receive. I doubt that mistake is causing your issue, though. Be aware that the Nabu uses a non-standard baud rate and your adapter needs to be able to match the baud rate of the Nabu. If you can get one of the Dtech adapters, those are confirmed to be able to operate at the non-standard baud rate of the Nabu and install easily without a bunch of driver issues. No panda bear mini CD needed. By the way, I believe the Nabu keyboard is a serial ASCII keyboard (with a non standard baud rate). It's a nice keyboard but the TV/Nabu switch (that toggles the RF modulator on and off) being where the backspace normally is can be annoying.

[@Epictronics1]

Thanks, I'll re-twist the cable in my next attempt. I may order a DTECH, but I have something else I may want to try out instead. I think I'll leave the NABU kb mod to someone else :)

[@andrewmackie5110]

And the keyboard innards are worth a gander. It's practically a Motorola 6800 micro in its own right.

[@Epictronics1]

@@andrewmackie5110 Awesome, we'll have a look in part 2. I think the kb also uses RS-422

[@bobweiram6321]

I also picked up a NABU. The keyboard uses the same Alps SKCC switches as the Macintosh M0110. Getting it to work with the PC will be a fun challenge. It has a great build quality!

[@Epictronics1]

Yeah, they are just turned 90 degrees and have a shorter stem. I think the kb uses RS-422. Hopefully someone clever figures it out so we can start building adapters :)

[@Epictronics1]

Now on patreon.com/Epictronics

[@UpLateGeek]

With the black monitor on top it kind-of looks like the IBM JX that was our family computer back in the day. Which coincidentally was also released in 1984. Sometimes with those USB serial adaptors there are settings in the driver properties to change the speed, parity, stop bits, etc., so you might want to check that out.

[@Epictronics1]

cool, I had completely missed that there was an IBM JX. I had to look it up, it looks awesome. Now I want one : ) You're right, they are very similar looking. Perhaps IBM was inspired by the NABU? If the JX came out in 1984 it was released one year after the NABU. (my NABU is from the second year of production)

[@frnno967]

Double check your wiring to the RS-422 adapter. I found that some of the documentation online on building the cable wasn't clear because it didn't state if it was from the perspective of looking at the male or the female end of the cable, and the wires end up flipped as a result.

[@Epictronics1]

Interesting. I have never messed around with RS-422 before. It's not entirely clear to me how to flip the connections. It seems to differ quite a bit from the usual Tx/Rx I remember from back in the Arduino/FTDI days

[@frnno967]

@@Epictronics1 RS-422 uses differential signaling for greater noise immunity, so there's two wires in each direction. If the two wires of either pair are reversed then the polarity will be wrong and the bits won't be understood. And if the RX and TX are flipped then nothing will transmit of course. But here's to hoping it's just a driver issue 👍

[@tekvax01]

yes. rs-422 is differential, plus and minus tx pair and plus and minus receive pair. as you might guess the tx must connect to the rx (think null modem DTE and DCE) the Baud of the sony RS422 protocol is 38.4k 8bit odd parity, 1 stop bit. RS-422 comms can be very confusing, just remember to connect the phase correctly and tx to rx, not tx to tx.

[@Epictronics1]

@@tekvax01 Thanks. I'll try to flip them and report back

[@Wormetti]

The fan issues seem common on these. Some can be fixed just by adjusting the screws, moving or rotating the housing. Bending the fins with pliers or filing should be a last resort but it definitely works.

[@Epictronics1]

Yes, I considered using sandpaper while the fan was still in the housing but decided to check what the actual cause was

[@Wormetti]

@@Epictronics1 It's good to find out the cause of the issue. I would expect them to work fine when new but they've likely moved or expanded after sitting for decades.

[@Epictronics1]

@@Wormetti That is definitely a possibility. My first thought was that maybe these were manufactured and tested in an environment cooler than what I consider room temperature. aluminum expands ever so slightly with the ambient temperature. They should of course have tested the fan at -55C to +125C (MIL) since this fan is obviously a very expensive high end product, probably intended for way more demanding applications than a bloody PC.

[@AWalYT]

RS-422 is a tricky one...DJ's software sets an odd baud rate that might throw off the adapter. The DTech branded adapters most of us are using contains an FT232, which seems to handle this okay. If your device is also running an FTDI chip the first thing I'd suggest is to see if the FTDI CDM v2.12.06 driver works with it, as this 2014 driver was the last version released before the windows provided drivers started messing up counterfeit chips. If the DB9 on your adapter is 1-5 TXD+,TXD-,RXD+,RXD-,GND then your cable should match the DTech one: DB9-1 to DIN5-3 and DB9-2 to DIN5-5 as a twisted pair with DB9-3 to DIN5-4 and DB9-4 to DIN5-1 as another twisted pair. Ground isn't connected at the NABU, but may help with noise on longer cables. In my own experience I used some old solid core network cable and used two of the twisted pairs to connect the lines as described and have had no trouble leaving the ground connected.

[@Epictronics1]

I had completely forgotten about that old FTDI driver bug. I actually had a problem with it back then on a project. I'll try with that driver, thanks.

[@1BitFeverDreams]

I've read yesterday that the fan only needs to be unscrewed (3 central screws) and rescrewed as this solves a slight unalignment problem. You actually did this as part of your filing so you couldn't confirm it was solely the filing that did the trick! I'll get mine mid March and I'll be able to confirm or infirm It's just the screws

[@Epictronics1]

Great, looking forward to the update. Enjoy your NABU :)

[@1BitFeverDreams]

​@@Epictronics1 finally had time to make my cable this morning. Happy to report it worked on the first try. As for the fan, I really tried to only rescrew the 3 screws but it felt like having 3 variables but only 1 equation. In the end, I went with Rudy's method of slightly bending the fins.

[@Epictronics1]

@@1BitFeverDreams Awesome. Enjoy : ) I'm a bit stuck because my analog scope cant show me what the converter is sending to the NABU. I might order a DSO tomorrow. It's about time I upgrade anyways :)

[@kittyztigerz]

i was digging around in my shed find more 2.5 floppy disk and drive and few stuff i just filling this box up with ton of old machine stuff for you keyboard clicker noise i like it it feelback clicking i dont know too much about that machine in videos and far i know you going need reprogram ci chips for it read adapter otherwise not work and someone was using machine adapter hook up to it if i find that video i may come cross it somewhere

[@wskinnyodden]

RS485 I believe is the correct serial protocol.

[@ropersonline]

Does the USB-to-serial adapter have enough power and the right voltage levels and follow the TIA/RS-232 standard closely (or perhaps loosely?) enough for the NABU's taste?

[@Epictronics1]

I don't know yet. My scope is analog so I need to send a continuous signal to check

[@Wormetti]

I see you didn't put NABU in the video title, good thing I'm already subscribed so I saw it anyway. I'm a bit NABU obsessed since Adrian's video. What is that RS422 adapter? It's not the DTECH that most people seem to be using. Assuming the cable is wired correctly, I wonder if it's incompatible with that odd baud rate or if it's a flow control issue.

[@Epictronics1]

Thanks for the heads-up. I have now added "NABU" to the title. Ok, I didn't know the baud rate could be an issue. I may order a DTECH now that I'm aware of this.

[@Wormetti]

@@Epictronics1 You can change it to 115200 in DJ's software or you can try some other NABU adapter software, there are so many now.

[@Epictronics1]

@@Wormetti Excellent, I'll try 115200. Thanks

[@RudysRetroIntel]

Try using Windows 10 as it already has the drivers. If it still fails, look at U12 and U13. Thanks for sharing

[@djatomist]

Mine didn’t have the glue on the fan screws and came right out but I did the same thing and sand the blades down a bit.

[@Epictronics1]

Nice, that glue made the disassembly a pain

[@nicoruizmza]

Maybe u already did this but, did u down the speed ? like 9600 and/or play the values? 4 bits, 8 bit, etc for example?

[@Epictronics1]

No, I didn't think to try a much lower speed. I'll give it a try

[@Poki3]

5:18 - When you start a computer and it sounds like an old 1 cylinder engine...

[@Epictronics1]

yeah, it actually sounds a bit like my good old Royal Enfield, but without the "thump"! :)

[@paulwratt]

you should probably go over the last RS422 video DJ Sures did, might at least give you some ides of what you can do with the adapter

[@Epictronics1]

I rewatched it but I can't spot any mistakes in my wiring. I'm now trying to find some info on how to test my RS-422 converter with the scope, but I'm not having much luck

[@paulwratt]

@@Epictronics1 if its a USB converter, then it is probably sending 5v to the RS422 - it will work, but the actual values for "good" RS422 are 9v-20v (I think - basically 12v on most older equipment) - but that might not be related to the issues you are having (which is why I did not mention it in the OP) - also verify TX RX cross-over pairs - apart from that, there is almost no difference to "simple" RS232 (like used with most RPi)

[@nickwallette6201]

I kinda want one of these to turn into a terminal, but the last batch didn’t have keyboards anymore. :-( Not sure whether we’ll see a fully stocked one again - I think I may have missed the boat. I have no love for those AC fans. It may be a beast, but I think I would rather just replace it with a normal 12VDC fan anyway. Those are quiet, but of course they are - they’re all hub and no blade. ;-)

[@Epictronics1]

True, we don't actually know how efficient it is : ) Let's hope they put out a few more on eBay with kb

[@andrewb9830]

Could try also to properly ground the cable to either the DIN end or to the RS-422 end but not both and see if it makes a difference. Also make your wire shorter. Still looks too long. I made mine 6 inches.

[@Epictronics1]

Ok, I'll try that, thanks

[@nevets9436]

Isn't RS422 cable is supposed to have positive and negative pairs for TX and RX twisted together? Looks like your cable had four sets of twisted pairs instead of just two (RX and TX).

[@Epictronics1]

Yes, I just twisted/soldered them together to get rid of the four unused wires. I didn't think of the fact that I could have taken the advantage of twisting the wires correctly to improve the cable

[@The_Traveling_Clown]

I might purchase another one.

[@Epictronics1]

:)

[@ironhead2008]

If the issue was just excessive paint, I imagen the fan would have clearanced itself after some use.

[@Epictronics1]

Yes, that's very likely, it didn't take much to remove it

[@RetroHoosk]

I couldn't get my converter to work on Windows, but it was flawless on Linux, not sure if you might want to try that?

[@Epictronics1]

Thanks, that's useful info. I'm a linux noob. What dist would you recommend to do a quick test?

[@lexatwo]

​@@Epictronics1 Linux Mint or Ubuntu are usual suspects when suggesting "noob friendly linux distro" to someone.

[@Epictronics1]

@@lexatwo ok, cool, thanks

[@MrWaalkman]

@@Epictronics1 I would create a Linux "appliance" in Virtualbox.

[@saleendriver]

Good luck on this one......feels like a long slog to me.

[@Epictronics1]

We'll get there eventually :)

[@saleendriver]

@@Epictronics1 of that I have no doubt

[@billmilligan1705]

But it's an incomplete Nabu system. It doesn't have the ethernet adapter, CD-ROM, floppy and hard drive interface, the enhanced multimedia video card and sound adapter or the SQZ adapter.

[@Epictronics1]

That's what hacking is for ;)

[@johnmay4803]

im catching up on some of ur vids

[@Epictronics1]

This project might actually be up next! It depends on if I have a part in my stash. Good choice to watch this vid this week :)

[@johnmay4803]

@@Epictronics1 would there be any way to adapt a hdd to it like the ibm 5150 has that extra addon for hdds and more drives?

[@Epictronics1]

@@johnmay4803 There is a project to add an SD card. I'm hoping for a project to add a real MFM hard drive :)

[@Sorbus79]

the Sultans of Ping

[@Epictronics1]

haha, yeah, I actually prefer Ping over Swing :)

[@ericblenner-hassett3945]

You skipped past testing if TX and RX were reversed on the adapter. Those old enough know TX on one to the RX on the other and some have ' simplified ' it by marking TX as RX on their pinouts for those that do not know to swap them and not tell anyone.

[@Epictronics1]

This is the first time I use RS-422 and just found out about this possible issue. I'm actually sitting down as I write this and trying to figure it out. I found the marking on the module confusing, So far I have found four different ways manufacturers label the Tx and Rx and non of them corresponds to my module. My module is marked (T/R+)(T/R-)(RXD+)(RXD-). I'm sure I'll figure it out as I keep reading but I don't mind some help :) What wires should I swap?

[@sebastienmonette6659]

​​@@Epictronics1To me it seems the T/R+ and T/R- lines are the Tx+ and Tx- lines and the RXD- and RXD+ are the Rx+ and Rx- lines If the connections are swapped on the controller, the Tx+ from the controller should be linked to the Tx+ line on the Nabu and so on for the other lines.

[@chaoticsystem2211]

It's 1984 and you need to go to bed now! (my experience)

[@christopherjackson2157]

Probably jar jar binks ;)

[@Epictronics1]

:)

[@21stcenturyrambo16]

Isnt Nabu where Jar Jar binks comes from?

[@Epictronics1]

Yepp, apparently it's somewhere in Canada ;)

[@michaelfuller34]

…or at least in Canada😂

[@xianox8]

Usb to rs232 are notoriously unreliable aren't they? I'd skip it tbh

[@Epictronics1]

Unfortunately, it's not RS232, The NABU uses RS422 :/ There is a hack though. I might go down that road instead

[@xianox8]

@@Epictronics1 oh riight.i learned something new then. Will be interesting to see how it goes. :-)

[@Mueller3D]

Your RS-422 adapter is probably fine. The issue may be flow control. See this video: kzbin.info/www/bejne/hoqmapmah86NnqM

[@Epictronics1]

Thanks, I'll check

[@tokul76]

Rs232 vs uart

[@Epictronics1]

Unfortunately RS-422

[@tokul76]

Noel's retro lab. Serial comunications with cb2 computer. Other retro dude had problems with serial coms. Or I am confusing rs422 and your usb converter is for rs422 and not for other serial coms

[@Epictronics1]

@@tokul76 Yes, the NABU communicates with RS-422. Good in a way. But also bad, because I don't have a spare adapter to try