Jetpac  (actual) arcade version

Version 1.0 - released on October 14th, 2026

Jetpac (Arcade version) is an action game for the Taito L System arcade hardware.
Its a fly around and shoot at aliens-type game

TL;DR version: Jetpac is a classic shootemup game for the ZX Spectrum computer, that
has now been ported to Taitos L System arcade hardware (specifically to Plotting).

Basic information: Jetpac is a platform video game originally developed and published
by Ultimate Play the Game and released for the ZX Spectrum in 1983 (and subsequently
ported to many other platforms since). The game follows Jetman as he must rebuild his
rocket using a jet pack in order to explore different planets, while simultaneously
defending against hostile aliens (read more here).

Why?: Back in 2018 I coded a remake of the Commodore 64 version of SQIJ for the ZX Spectrum
 a game that was famously and literally unplayable on the Spectrum. Shortly afterwards
I ported that to Taitos L System and ever since Ive wanted to do something else for that
platform. Sometime over the summer of 2026 it occurred to me that Jetpac  which is a pure
action Shoot Em Up game  would be perfect to port to an actual arcade platform  and here we are.

 
Gameplay description:
As explained above, you play as Jetman and must rebuild your rocket and then refuel it in
order to explore different planets, while simultaneously defending against hostile aliens.
There are 4 different rockets to build and each rocket has to be refuelled 4 times to progress
to the next rocket. Manage to play all the way through, and you will start from the beginning
again, racking up even more points.
 

Nice to know:
This is not a game you just play on your PC  you can, but theres a bit more to it than that.
The game has been coded for an actual 80s arcade platform, so you have to use an emulator, but
luckily MAME exists. MAME emulates arcade hardware and maps joysticks and buttons to the keyboard
so you can play the old (and in this case, new) games on your PC. This game has been coded to run
on Taitos Plotting hardware, so while this game is called Jetpac, the file that you drop into
your MAME installation is should be called plotting.zip (rename the file you download), replacing
that game (if you have already have it).

 

Installation:
Place the plotting.zip file in your ROMS folder under your MAME installation folder (you dont
have to unpack it  but you can also unpack the files into a Plotting folder).
Notice that the file is called plotting.zip because it will replace that game in MAME (you can
also rename the files in the archive and run it as plottingb.zip). You will also have to start
the game from the commandprompt with mame plotting as trying to run the game from the GUI will
throw up an error. Alternatively, Im sure itll be included in HBMAME (HomeBrewMAME), in which
case itll be possible to run from the GUI.

All the above are if you are going to play the game on an emulator, but if you have an original
Plotting arcadeboard and a chip burner, then it should run on the original hardware too. That was
the whole idea of it. But heres the thing, MAME doesnt emulate the arcade hardware exactly, only
well enough to run it emulated  its possible to code something that will work in MAME, but wont
work on the real hardware, so until someone tries it out on the real hardware, I cant gurantee that
it will work on the real board. Hopefully someone will try and get back to me if there are anything
that needs to be fixed (that was the case with SQIJ).

 

Controls:
Use the joystick and the buttons mentioned on the screen. As this is an arcade game remember to
insert coin with the 5 key before you can play (start a game with keys 1 or two for a one or 2 player game).


Legal Blurb:
This game is FREEWARE and must remain freeware. I would also ask that the game will only be available from this website.

Copyright and credits:
The original ZX Spectrum game was developed and published by Ultimate Play the Game and written by Ultimate co-founder Chris Stamper.
This 2026 port was coded by Sren Borgquist  aka. Sokurah. and based on the reverse engineered source code
by Michael R. Cook  aka. mrcook and only made possible by the reverse engineering of the Taito hardware by Adrian aka. cmonkey.
Graphics by Fransouls.
Music by Spacefractal.
 

Version history.
v1.0  October 14th, 2026
 

Unadressed issues.
Overall Im very happy with how this game has turned out, but there are a few places where things could be improved.
The worst is the collision detection between your laser shots and the enemies. Converting the drawing of the laser shots
in the original game to being sprite based (because the arcade platform doedsnt support drawing directly to the bitmap plane)
took at lot of work and turned out to be a bit wonky to be fair. Now you have to be really careful shooting at enemies  especially
near the edge of the screen, where it will also sometimes look like your laser is coming from behind you (harmless). As a consequence
of that, the previous safe-spot in the top right corner of the screen is not so safe anymore. Thats an unfortunate  but fun  side
effect ?? Sometimes your shots will also pass through the enemies, sorry about that  Ive done my best. Eagle-eyed persons may also
notice that if Jetman is passing through the right side of the screen while carrying fuel or part of the rocket, then the items wont
be clipped perfectly. I cant do anything about that, but theres a technical reason I wont go into details about ????
 

Disclaimer / possible future improvements.
This version hasnt been tested out on the real hardware yet.
Hopefully it will soon and if theres any problems I will fix them and upload a new version.
 

Final disclaimer.
At the time of writing this, coding communities are up in arms regarding AI slop and the idea of generating games in no time,
from prompts using AI, but this is not that. I had a fantastic starting point  the (fan reverse-engineered) source code,
but although the Spectrum game and the arcade hardware shared the same CPU, they have nothing else in common and I used Claude
to crack this nut by asking Wheres the best place to intercept the drawing of sprites so I could port that part.
Much easier that reading through almost 6.000 lines of source code. It wasnt quite that easy though  issues kept appearing,
and from start to finish this project took several months. Still, it was a fun project and Im quite happy with the final product.

Enjoy.
