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JetPac RX

Posted: Tue Jul 07, 2020 11:15 am
by highrise
For those not on Facebook, here is a quick work in progress look at my latest coding attempt to ruin a thousand childhood memories.

Over the last few weeks I've been working on Michael Cook's excellent disassembly of JetPac. As with all these things, it started out with me simply wanting to learn by making a few mods, and then getting carried away with requests and suggestions.

Obviously, I won't be distributing this game. Instead I have gone through the rather painstaking task of adapting the disassembly to create a memory matched copy of the tape version. The updated version is then compared to this, and the modifications are converted into a POK file which works as a patch. In this way only the changes and additions I have made are distributed. The POK file can be applied using popular emulators such as FUSE or Spectaculator.

Additions include randomised levels, graphical tweaks and some basic particle effects. Plenty more to come but I'm being very careful to respect the original and just add a little makeup here and there to hide its age. The original will always be there.


Big thanks to Michael Cook for all his work in disassembling the code.

https://youtu.be/bJ0mYt8Jlho

Re: JetPac RX

Posted: Tue Jul 07, 2020 12:05 pm
by Morkin
Looks nice..!

I like the colourful/varied platforms. And that classic 'typically-space-retro-yet-futuristic' font suits it nicely.

Does it still run in 16K?

Re: JetPac RX

Posted: Tue Jul 07, 2020 12:12 pm
by highrise
Thanks - the font comes from Lunar Jetman, clearly the obvious choice. It definitely wont run in 16k now, though I doubt that is an issue for anyone.

Re: JetPac RX

Posted: Tue Jul 07, 2020 1:40 pm
by Morkin
48K is perfectly fine for most people, but I thought I'd check in case you'd performed some code marvels..!

Re: JetPac RX

Posted: Tue Jul 07, 2020 3:18 pm
by ZXDunny
Lovely. How about seeing if you can get some vsync in there? Jetpac with no flicker would be lovely :)

Re: JetPac RX

Posted: Tue Jul 07, 2020 3:48 pm
by highrise
the vsynch is tricky because I can't distribute the code, only make a patch that fits over the original. But I'll see what I can do.

Re: JetPac RX

Posted: Fri Jul 10, 2020 2:56 am
by highrise
Here is an update, running in contended memory. Not sure how I'm going to get the patch to do this but I'm convinced it's what needs to be done now, it just has to run there to be that bit smoother and more challenging.

https://www.youtube.com/watch?v=lVucY-gV_s8

Re: JetPac RX

Posted: Wed Jul 29, 2020 11:07 pm
by BloodBaz
JetPack RX looks fantastic. Great job there!

I spent many hours last year advancing the disassembly and annotation of Atic Atac but I'm in a quandry about the legalities of making the disassembly public domain. As you started with a disassembly of JetPac, can you advise me on if I should be allowed to push Atic Atak disassembly onto GitHub or similar?

Cheers,
BloodBaz

Re: JetPac RX

Posted: Wed Jul 29, 2020 11:18 pm
by Freespirit
Great work, looking forward to seeing future updates.

Re: JetPac RX

Posted: Wed Jul 29, 2020 11:34 pm
by Freespirit
BloodBaz wrote: Wed Jul 29, 2020 11:07 pm JetPack RX looks fantastic. Great job there!

I spent many hours last year advancing the disassembly and annotation of Atic Atac but I'm in a quandry about the legalities of making the disassembly public domain. As you started with a disassembly of JetPac, can you advise me on if I should be allowed to push Atic Atak disassembly onto GitHub or similar?

Cheers,
BloodBaz
Interesting question. As the Jetpac disassembly hasn't been removed from this Forum, someone thinks it's ok. I'd be interested in Atic Atac as i've just started learning assembler, i could learn a lot from it. My first 2 games from WH Smiths randomly picked from the shelf were Manic Miner and Atic Atac. How lucky was that?!

Re: JetPac RX

Posted: Wed Jul 29, 2020 11:49 pm
by cmal
It's looking super cool and very smooth! Looking forward to future updates. Great job!

Re: JetPac RX

Posted: Thu Jul 30, 2020 7:31 am
by ketmar
BloodBaz wrote: Wed Jul 29, 2020 11:07 pm I spent many hours last year advancing the disassembly and annotation of Atic Atac but I'm in a quandry about the legalities of making the disassembly public domain. As you started with a disassembly of JetPac, can you advise me on if I should be allowed to push Atic Atak disassembly onto GitHub or similar?
i believe that if you will clearly say that the code is not your own, but a disassebly, there should be no problems. i also think that you should legally own the game, but IANAL. i mean, distribution rights for Ultimate games are unclear, so you'd better have your own.

Re: JetPac RX

Posted: Fri Jul 31, 2020 1:05 pm
by highrise
Jetpac dissassembly is not available online, however there is a skoolkit file which allows you to create a dissassembly if you have an original rom, this is how it is possible to share it legally, because it can only be made it you have the actual rom itself, and by that I mean the cartridge rom.

Re: JetPac RX

Posted: Wed Aug 12, 2020 6:29 pm
by ZXOxo67
Will you post the patch Here too? Please, im not a facebook user and im no Patriot user too. Maybe itch.to?

Re: JetPac RX

Posted: Thu Aug 13, 2020 5:30 am
by ZXOxo67
Sorry, not Patriot, patreon

Re: JetPac RX

Posted: Thu Aug 13, 2020 3:28 pm
by obo
BloodBaz wrote: Wed Jul 29, 2020 11:07 pm I spent many hours last year advancing the disassembly and annotation of Atic Atac but I'm in a quandry about the legalities of making the disassembly public domain.
I did Atic Atac a couple of months ago to help Tom-Cat with some details for the C64 version. Some kind soul has put it on GitHub here -- like you I wasn't comfortable with doing it myself! Might be interesting to compare them and see if we agree on the logic. :)

I've done most of Sabre Wulf too, which I started when I was working on TileMap. The similar engine code meant I was familiar with their seemingly scattered handler logic, so I got most of AA done in a week or so.

Re: JetPac RX

Posted: Sat Aug 15, 2020 12:05 pm
by Andre Leao
Game is released, and the full review is here:

https://planetasinclair.blogspot.com/20 ... ac-rx.html

Re: JetPac RX

Posted: Sat Aug 15, 2020 12:30 pm
by ZXOxo67
Perfect!!!! Im so happy....... :D

Re: JetPac RX

Posted: Sat Aug 15, 2020 10:24 pm
by Morcar

Re: JetPac RX

Posted: Wed Aug 19, 2020 12:26 pm
by Andre Leao
Rev_Stuart_Campbell wrote: Wed Aug 19, 2020 10:59 am Why isn't this getting more love? It's a substantial and excellent reworking of one of the Speccy's most iconic games that gives it a whole new lease of life. Is it because you have to faff around with it a bit?
Have you seen the review on Planeta Sinclair? More love is impossible (10 is the limit)... :)

Re: JetPac RX

Posted: Wed Aug 19, 2020 2:25 pm
by Alessandro
Rev_Stuart_Campbell wrote: Wed Aug 19, 2020 10:59 am Why isn't this getting more love? It's a substantial and excellent reworking of one of the Speccy's most iconic games that gives it a whole new lease of life. Is it because you have to faff around with it a bit?
No offence to anyone, but personally I don't see the need for these remakes, or reworkings, of classic games, other than as proof of concepts.

Apart from a graphic restyle, which in my humble opinion is not better than the clean and simple look of the old sprites, and a few modifications, this is basically the same game of 1983, with all of its obvious limits. I'd rather stick with the original, although I have played it ad nauseam back in the day, and I would hardly spend my already scarce free time by playing it again.

Re: JetPac RX

Posted: Wed Aug 19, 2020 9:20 pm
by Turtle_Quality
Even if it "only" gives re-definable keys it still makes a classic game more playable. But I like the graphic updates also - great job ! Getting V-synch right to remove flicker would have helped Jetpac, but as I remember Imagine's Arcadia (for instance) was very flickery and would benefit a lot if that were possible. Also Arcadia had trouble reading the keys for later releases of the Spectrum. If it's possible to fix it now, why not ?

And the Penetrator keys fix made that game so much better

When it comes to retro games, there are many there that have annoying flaws that could have been fixed to improve them. AST Moore has fixed quite a few.

Can't wait to see the Lunar Jetman update ...

Re: JetPac RX

Posted: Thu Aug 20, 2020 2:45 am
by ketmar
Alessandro wrote: Wed Aug 19, 2020 2:25 pm No offence to anyone, but personally I don't see the need for these remakes, or reworkings, of classic games, other than as proof of concepts.
the same can be said about the whole Speccy scene. ;-)

i guess it is basically the same nostalgia that drives other developers, only from the slightly different PoV. like, "oh, i always dreamed about fixing this and that in that game, and adding those two features, and..." and why not? in the end of the day, a developer had some fun, and it's already great. and there could be other people who liked The New Look and additions. double win.

but nevertheless, i can understand your fellings. i believe i am usually feel the same when i see new AGD/Churera game. ;-)

Re: JetPac RX

Posted: Thu Aug 20, 2020 9:22 am
by MarkRJones1970
If you're playing this on a Next and you try to save a snapshot to preserve your high score don't do it while the tune is playing as it doesn't like it and reloading it back in just results in a reset. Apparently it's due to the music driver. I've been told to stop the music playing by pressing a key then save your snapshot and that should work. https://www.facebook.com/MJones54321/vi ... 750122524/

Re: JetPac RX

Posted: Thu Aug 20, 2020 10:38 am
by toot_toot
I will give this a try later, I'm really looking forward to it! There was an updated version of Jetpac released a couple of years ago (can't remember it's name now), which did change the layout, but with this new version it really does feel like it's been totally updated while keeping the same classic gameplay. Almost as if Ultimate themselves released an updated version for their compilation release towards the end of their time with the ol' Speccy.

The upcoming 3D version of Atic Atac takes care of that one but I'd love to see the other earlier games updated too, Tranz Am, Psst and Cookie could all do with some extra improvements. Cookie especially would be amazing as a twin stick shooter, or at least with the automatic firing of the Smash TV computer conversions. I always found Cookie a bit too hard but see how it was probably imagined at the time as a twin stick shooter like Robotron 2084, but kept back by the technical limitations. Underwurlde could probably do with a bit of an update, but maybe it's just changing the awful way the enemies kept on knocking you down the screens that made it really frustrating to play. Even something simple like having the enemies only affect an energy bar instead of knocking you down would make it a hundred times better!