🇩🇪 Nixdorf LK-3000 Personal Computer: Part 2 (Let's Start Hacking It) [TCE

Описание: Let's see if we can put this machine to some use in 2025. I was initially just going to re-use the HPDL-1414 display modules but then thought it might be more interesting to use the whole machine as is ... it supplies a keyboard & display ... we just need to supply the CPU and firmware!

As the machine is quite simple I drew up a schematic on how I think it works, including the keyboard matrix ... we either check the data bus for a key being pressed (keyboard strobe), or we put an ASCII character onto the bus and get it displayed (display strobe). So simple that I almost understand it.

I designed some simple cartridge PCBs for initial development & testing - one cartridge with a prototyping area and one with a breakout header to allow development externally (i.e. wired up to an Arduino).

I captured some signalling on the cartridge interface (Saleae Logic 2) to get an idea how we should talk to it ... whilst the development cartridges are being fabricated, I can whip up some Arduino code to check the keyboard and print to the display.

All the details are on my Github for this machine which will be updated as I progress:
https://github.com/0ddjob/Nixdorf-LK-...

Some discussion of possible uses here:
https://forum.vcfed.org/index.php?thr...

00:00 ... Intro
02:42 ... The DL-1414 display module
03:35 ... Showing a cartridge in action
10:15 ... Another inside peek
12:00 ... Preparing to capture cartridge signalling
13:00 ... How it kinda works
15:45 ... Logic analyser (Saleae)
17:57 ... Final thoughts
18:40 ... Channel thanks & outro

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From Part 1:
Let's take a look at this interesting "personal computer" from 1979. It's essentially a language translator using cartridges but has a few other tricks: it can be used as a calculator, an electronic notepad, a filing system and also a remote computer terminal (via an acoustic coupler).

The machine has a very nice 16 character display (four DL1414 modules) and runs on four NiCd rechargeable cells. It also comes with a 6VDC power adaptor that can be switched between 120VAC and 220VAC.

There is very little inside the machine itself - a few logic chips, the display and the battery. All of the intelligence is contained within the cartridges: usually a ROM and a CPU-type device.

I couldn't find any information on the CPU-type chip - I'm assuming it's some sort of custom/cut-down Motorola 6800 with some internal program ROM and RAM ... ? Each chip is customised for the cartridge, bearing the cartridge's ID.

For example, the chip in the LK-3050 Spanish language cartridge is labelled:
LK3051M
7914 (datecode)
SC80230P

And in the electronic notepad:
SC80293P
8006
LK3500M

These are the cartridges I'm aware of:
LK-0280: Winter Olympics - Lake Placid
LK-0680: Summer Olympics - Moscow
LK-1001: Filing System
LK-3050: English-Spanish
LK-3060: English-French
LK-3070: English-Italian
LK-3080: English-German
LK-3090: English-Swedish
LK-3100: English-Polish
LK-3110: English-Portuguese
LK-3120: English-Russian
LK-3130: English-Greek
LK-3140: English-Arabic (also LK-3145?)
LK-3150: English-Hebrew
LK-3160: English-Japanese
LK-3170: English-Chinese
LK-3200: English-Spanish-French-German-Italian-Greek
LK-3500: Electronic Notepad
LK-3900: Calculator
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  / thecluelessengineer  
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Music by Karl Casey @ White Bat Audio
https://karlcasey.bandcamp.com
   / @whitebataudio