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Need some ideas for repurposing a Nixdorf LK-3000

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Retroplayer

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I absolutely love the aesthetic of this device. It is technically a handheld language translator with some other modules for calculator, phonebook, notepad, etc...

The device has a single row 16 character LED display. The cartridges usually came with a keyboard template that snapped in place to map the keys to the functions of the cart.

The unit itself was just the batteries, display, and keyboard. All of the smarts are in the cartridges.

I wrote some code to make a pi pico cartridge to re-use the display and keyboard quite a while ago, but I never finished the project because I just can't come up with a novel use for the limited screen and keyboard.

The code did implement some features such as scrolling the screen up/down and left/right maintaining a small buffer. It also allowed re-mapping of the keys. But I didn't get any farther than developing the drivers.

The above was made possible because there was an old magazine article (Popular Electronics July 1980) that gave the details of repurposing for a simple terminal connected to a parallel port.

Just tossing this out there in the hopes of getting some possible ideas for use for such a thing. I have a small collection of them that I picked up, so at least one is planned for just re-use of the housing and the display would be replaced with an OLED.

If you don't know what this is, here is a site that gives some details and shows some internal pictures:

Nixdorf LK3000 Saintummers Elektronik und Radio Projektseite

Nixdorf, Computer, Nixdorf LK-3000
www.saintummers.at www.saintummers.at

You can find the magazine article here. I didn't want to link directly to the PDF, so you will need to select July 1980:

POPULAR ELECTRONICS: Consumer Electronics and Experimenter magazine

Popular Electronics Magazine: 1954 through 1982 Consumer electronics and experimenter publication. All issues available for reading or searching.
www.worldradiohistory.com
 
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Some pics I had taken for sizing up the ability to fit a pico or ESP32 inside the cartridge.

I started on a cartridge PCB design, but my first iteration would just get wired directly.




395430897_1030774974806492_7640739959261848645_n.jpg395690196_731106298929693_7687960036745566918_n.jpg395730988_1519809665434747_8233830806591214752_n.jpg
 
16 characters is a bit of a challenge! Advanced unit conversion and scientific calculator?

You could use it as an authenticator device, either one that gives you a time-based code or with a challenge code that it responds to with another code.

Wifi signal strength meter if you have a Pico with wifi.

Mastermind or other game, press a key to switch between the 4 colored pegs and the guess results.

You could hang a "probe" connected to the Pico and display on the screen whatever the probe is measuring. So if using the cheap temperature/humidity sensors, you could use that.

If you have a webserver anywhere, it can display the status of a page or the result of a pre-canned query, like stock tickers etc; you could cycle through them with a key press. AAPL ^2.10 242.50 could mean AAPL (Apple Computer) up $2.10, current price $242.50
 
16 characters is definitely the main challenge, but for what it is worth, my display driver implemented a 32 character, 16 line buffer. So even though you can see only 16 characters at time, the "screen" could hold more data. I kept the buffer small because I thought it would be cumbersome to scroll through more than that.

That could potentially add table-based applications\games (2 column, 16 row table)

A magic eight ball type fortune teller was one demo I thought of today.

I added a typewriter effect to the display driver that I will need to still tweak which will "draw" the characters to facilitate this larger screen buffer.
 
The displays themselves are 7 bit ASCII (HPDL-1414) so through a bit of cheating, I could replace the display with something else. Though my initial goal was to retain the original limitations to spark creative applications.

The system uses 4 address lines and 6 data lines plus some control signals with some fairly ingenious multiplexing.

This is the cartridge connector (0.1" or 2.54mm centers conveniently):

Code: 
1 /RESET
2 /KEYSTRB
3 /DWSTRB
4 ADD3
5 ADD2
6 VIN
7 GND
8 5V
9 D5
10 D4
11 ADD0
12 ADD1
13 D0
14 D3
15 D2
16 D1

Address lines select one of 16 characters or one of 8 keyboard rows
Data lines carry either the 7 bit ascii data for the display or the state of one row of keys.

/DWSTRB display strobe
/KYSTRB keyboard strobe

/RESET is just the clr key connected directly for which an interrupt could be attached for things like a key modifier. It doesn't internally cause a reset of the components

I really need to make a schematic. But the mechanism is rather simple.
 
The components:
CD4053 Hex buffer (high current driver, essentially)
MM74C42 BCD to Decimal converter used for multiplexing
HPDL- 1414 Smart LED displays. 4 modules of 4 digits each

The majority of information cartridges contain a Mostek MK3870 processor and 2 MK36000 ROMs
The notepad cartridge has battery (1/3AAA nicad) backed ram and uses a uPD8048 (mask rom version) micro which is 8051 compatible. And industrious user could probably replace that with the uPD8748 which has UV erasable ROM.

There are two "Olympic facts" cartridges (summer and winter 1980) These are bit more rare, so I have not opened them.

There was supposedly also a modem available (LK-2010) which I have never seen in the wild
 
Retroplayer said:
Great work!

What have been your thoughts on repurposing it?
Click to expand...
I was originally just going to strip those lovely DL-1414 display modules and create a small, five module board that could be used by an Arduino or similar (I bought a bunch of these LK-3000s on ebay) ... someone has written a library to drive them:

github.com

GitHub - marecl/HPDL1414: Arduino library for HPDL1414 14-segment display

Arduino library for HPDL1414 14-segment display. Contribute to marecl/HPDL1414 development by creating an account on GitHub.
github.com github.com

Then I thought that it might be interesting to re-use the "computer" as is and found your post. I'm not very original when it comes to ideas ... the first thing I want to try is a simple clock/temperature display, something that I made years ago when I was fiddling with Arduinos. That early project just used four 7-segment displays so these DL-1414s would look a lot better.

You could use a stripped back Arduino (i.e. just the ATMega chip, crystal, etc.) with a battery-backed RTC and temp module.

If I could get that working, then could look at something fancier like an ESP32-based thingy that can use NTP to sync the time ... ? If that works then another idea is a "retro" YouTube subscriber counter.

Something I've been wanting to make for a while is a power display for our 10kW PV system. It has a pair for 5kW inverters that have WiFi dongles that I can use an app on my phone to query the current power output, etc. ... of course, all the data gets sent to a server in China ... but I've figured out how to query the data from the inverters via HTTP so that is something pretty simple an Arduino/ESP32 should be able to handle.
 
I actually have a few dozen of these displays: https://www.broadcom.com/products/l...numeric-displays/parallel-interface/hdsp-2133

I thought about wedging 4 of them into the Nixdorf, but with the limited keyboard, it didn't seem fitting to have a dot-matrix display. For now, the only thing I have done with them is connect them to my Commodore 64 for a neat little display.

A clock/ temperature rig could be fun. The ebay counter is much cooler.

Some other ideas that just came to mind:
Simple puzzle type games
Joke database
The magic 8 ball again
Chinese fortune cookie or horoscope (coupled with a tiny label printer?)
Executive decision maker
Social media ticker
Internet pager
ahead-of-its-time IM device using radio
Message board

Maybe some very limited text adventure game

I guess the applications for it will start rolling in once the hardware is in place.
 
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No photo description available.
 
Retroplayer said:
I actually have a few dozen of these displays: https://www.broadcom.com/products/l...numeric-displays/parallel-interface/hdsp-2133

I thought about wedging 4 of them into the Nixdorf, but with the limited keyboard, it didn't seem fitting to have a dot-matrix display. For now, the only thing I have done with them is connect them to my Commodore 64 for a neat little display.

A clock/ temperature rig could be fun. The ebay counter is much cooler.

Some other ideas that just came to mind:
Simple puzzle type games
Joke database
The magic 8 ball again
Chinese fortune cookie or horoscope (coupled with a tiny label printer?)
Executive decision maker
Social media ticker
Internet pager
ahead-of-its-time IM device using radio
Message board

Maybe some very limited text adventure game

I guess the applications for it will start rolling in once the hardware is in place.
Click to expand...
Some nice ideas there! I guess you need to try to forget what's available in 2025 and try to think back to the 1980s where a "pocket" sized computer with keyboard & display would've been something cool to carry around.
 
Exactly! That is the stalling point in many of my projects. Get too modern and we may as well just gut the case (I plan to do that with one)

A sci-fi element is ok, if the functionality was part of the sci-fi culture at the time.

Maybe that is the key: try to think of old sci-fi using a similar device.

Maybe a remote for K.I.T.T (Knight Rider)? Haha

Or perhaps a simple inference engine that appears like a retro AI assistant.
 
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I posted a video last night ... I captured the signalling on the cartridge interface. It does seem quite simple:

[1] Keyboard strobe active low and cycle through the addresses (columns) - check for key press on the data bus
[2] Put a character onto the data bus and, I guess, the display location on the address bus and set display strobe active low

Sp most of the time it's just waiting for a key press.

 
You are further along than I am, but if there is any information you are missing let me know. I may have it. I assume you have found the popular electronics article I linked in the initial post?
 
I realised that I don't need to wait for my breakout cartridge (just shipped from PCBway, probably another two weeks to get here) ... I can just remove the cartridge connector and stick a pin header on it which I can then connect to an Arduino for testing. This means the keyboard isn't easy to use so I also designed a simple replacement keyboard using Gateron low-profile KS-33 switches ... just for development outside the case.

I replaced all the capacitors - I see that they use either a tantalum or an electrolytic (1µF) on the keyboard interface board - I replaced everything with MLCCs, except for the 22µF axial near the power supply which I replaced with same. Hoping that might improve the reliability as it started misbehaving last night after some time on.

Whipped up a simple Arduino program to strobe the keyboard and report key presses - will test tomorrow! The first new software written for the LK-3000 in 40 years?? :)

All the updates on my Github.
 
I was going to mention that a header works in place of the cartridge port when I seen you solder it in your video. I did that to a unit I had dedicated to development a while back.
 
I ordered a few of your prototyping boards. I had another order I was sitting on, so tossed it in the cart.

Thank you doing these boards!
 
Retroplayer said:
I ordered a few of your prototyping boards. I had another order I was sitting on, so tossed it in the cart.

Thank you doing these boards!
Click to expand...
Hey, no problem! I was going to ask if you wanted me to send you one - my little channel is sponsored by PCBWAY so they give me free boards. I don't have them yet, takes about two weeks to arrive.

I'm going to get a 12mm tactile "development" keyboard made ... thought it might be easier than using the original - can send you one of those if you like? Although, it's a bit bigger so probably won't pass as a "letter" :)

Nixdorf_LK3000_Development_Keyboard.png
BTW, good work on finding the Popular Electronics article - didn't realise it was about hacking it. Very interesting. And from there I found that someone has developed a technique to dump the 3870 CPU ROM contents ... something on the "to do" list so this little machine's history is properly documented/archived.
 
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