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Mono-Key King

A text-mode version of a vintage game, on a vintage computer

david-plassDavid Plass
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I built this game as part of the Phase101 "Donkey Kong" Game Jam. I picked the Tandy 200 as the platform - it's my current favorite vintage computer.

The challenge was "to create an inspired DONKEY KONG GAME or similar (you are allowed to use your imagination). So a platform game with Donkey Kong." But due to IP restrictions we were told not to call it Donkey Kong. 

After some brainstorming I named it MONO-KEY KING.  It's in MONOchrome, you use the KEYboard and the monkey KING is the baddie.

See the Build Log for more history and details about the implementation.

Video of full play-through:

mkk.co

Binary for Tandy 200

co - 4.50 kB - 08/25/2026 at 22:58

Download

mkk.asm

Source code

plain - 74.69 kB - 08/25/2026 at 22:58

Download

  • Wrapping up

    David Plass • a day ago • 0 comments

    Almost didn't make the 3rd level but 2 didn't seem enough so I added the 3rd.

    Challenges:

    automatically moving conveyor belts

  • In the original Klingon

    David Plass • a day ago • 0 comments

    Comparison to the original

    Barrels

    Firefoxes

    Fireballs

    Hammers

    Scoring

    Falling

    Rivets

    Conveyor belts/concrete piles

    Levels

  • Shrinkage

    David Plass • a day ago • 0 comments

    TBD

  • Splash screen

    David Plass • a day ago • 0 comments

    Space was at a premium. I didn't want to store the splash screen as an RLE-encoded 

    bit-encoded. wrote it myself

  • Storing game boards TBD

    David Plass • a day ago • 0 comments

    Original: literal stored in the asm

    Took too much space. (show your work)

    Worked with Gemini to come up with a RLE compressed version. Its code was ok, but I subsequently improved it (see later entries)

  • Emulation & Assembly

    David Plass • a day ago • 0 comments

    cpu.exe vs virtualT

  • Initial decision: language

    David Plass • a day ago • 0 comments

    Once I decided to join the jam, I thought about all the "moving parts" that would have to be in play: barrels, Mario, er...other stuff... Look, I never really played Donkey Kong so my knowledge was mostly cultural rather than personal. 

    I watched a BUNCH of videos about DK play throughs, and some level-specific videos. I read a lot about the algorithms, even looked at some code.

    From previous experience I realized I wouldn't be able to use BASIC on the Tandy 200 - it would be just too slow. So I decided to write it in (8085) Assembly Language. 

    I've written _some_ assembly code, but not a lot. Only 386 professionally, and very little 8085 at all, so it was definitely going to be a challenge.

View all 7 project logs

  • 1
    Installing the emulator

    https://sourceforge.net/projects/virtualt/ - available for Windows, Linux and Mac.

    For Windows, download the zip and unzip it to a place where you can run it.
    Then just double-click on the exe.

    For other systems, IDK

  • 2
    Loading the game into the emulator

    From the emulator "Emulation" menu select "Model" then "T200". (Also known as Tandy 200.) You only have to do this once to change it to T200 mode.

    Then, from the "File" menu select "Load file from HD" and select the "mkk.co" file from your local HD.

    Using the arrow keys, select BASIC in the main menu, then hit "Enter". It should drop into TANDY 200 BASIC.

    CLEAR 256, 56000
LOADM "mkk"

    Video of loading:

  • 3
    Running the game

    Follow the instructions in the previous step to load the game

    Using the arrow keys, select BASIC in the main menu, then hit "Enter". It should drop into TANDY 200 BASIC.

    Then run the command:

    CALL 56000

    If you quit the game, use that command to restart it from the beginning.

    The emulator should retain its settings/memory so you shouldn't need to reload the game into the emulator to play, just use the CALL statement to restart the game.

    To get back to the emulator's main menu, type MENU and hit enter.

View all 3 instructions

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