Galaforce 30th Anniversary Full Source code for BBC Micro

reminisce about bbc micro & electron games like chuckie egg, repton, elite & exile

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Kevin Edwards
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Galaforce 30th Anniversary Full Source code for BBC Micro

Postby Kevin Edwards » Sat Jun 25, 2016 11:50 am

Hi,

30 years ago this summer I was polishing and tweeking the BBC Micro version of Galaforce in readiness for its release in September 1986 by Superior Software. This wasn't my first published title, but it's one of the games that i remember fondly. It started life as some 'fast' sprite routines I was playing about with and quickly evolved into a full arcade style game influenced by many other popular shoot-em-ups including Galaga, Star Force and Galaxians. The name I chose for my game was simply taken from Galaga and Star Force.

Following on from BeebInC's recent Disassembly of the game I thought now would be a good time to also release the original source code into the wild - congrats BeebInC for your hard-work pulling the code apart!

Hopefully it will give others some useful knowledge and techniques and provide an in-sight into how games were developed in the 1980s.

The entire game was written in 6502 assembly using the BBC Basic assembler. The game code was split into simple modules, with obvious names, SPRITES, BOMBS, STARS, WAVE etc. These were loaded and assembled as file 'overlays' to allow many separate source files to be used - a single file would not fit into memory and would have been a nightmare to edit. The file MASTER is the file that builds the game code and this is a good starting point for those interested in the build process I used. BOOTing the disk will assemble all of the game code and produce the final game executable - make sure the image isn't write-protected. Both sides of the disk image contain code and data for the game.

Anyway, I hope there is something in there that is of interest to you and perhaps it will inspire others to write their own 6502 games. :D

Kevin.
Attachments
GALBSRC.zip
BBC Micro Galaforce Source code
(62.82 KiB) Downloaded 180 times

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leenew
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby leenew » Sat Jun 25, 2016 11:54 am

Brilliant! =D>
Thank you Kevin :D
Lee.

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sydney
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby sydney » Sat Jun 25, 2016 11:58 am

=D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D> =D>
WOW!
Thank you so much , it'll be great to see how it was done back in the day. I find it hard enough using modern tools and find it amazing anything was ever written at all using the beeb's own assembler!

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davidb
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby davidb » Sat Jun 25, 2016 8:35 pm

Did anyone ever figure out and document the protection on the Acorn Electron version?

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Jimbob
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby Jimbob » Sun Jun 26, 2016 10:18 am

Kevin, you're a top dude - thanks very much for Galaforce! =D>
Here's to 30 years of me getting greedy and crashing into the side of a giant face
Repton Shoes!

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pixelblip
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby pixelblip » Sun Jun 26, 2016 10:28 am

Ahh Galaforce.......has it been 30 years.
It had very good graphics/baddies. Very fast pace as well.
It's the green baddies I remember the most.....and that brilliant music...very catchy arpeggios

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davidb
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby davidb » Sun Jun 26, 2016 11:00 am

davidb wrote:Did anyone ever figure out and document the protection on the Acorn Electron version?

Oops! I meant to post this to the disassembly thread! :oops:

Anyway, back on topic: thanks for publishing the source code for the BBC version, Kevin! Do you still have the Electron version's code lying around? :)

Kevin Edwards
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby Kevin Edwards » Sun Jun 26, 2016 11:15 am

As requested, here's the Electron version too - pretty sure this is the final build i used - not checked.

Much the same as the BBC Version, but runs in MODE 5 and has simplified music ( single channel melody ).

Kevin.
Attachments
GALAELK.zip
Acorn Electron Source code for Galaforce
(65.29 KiB) Downloaded 73 times

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leenew
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby leenew » Sun Jun 26, 2016 11:43 am

Wow!
What other treasures may be lurking on that hard drive Kevin? :shock:

Lee.

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davidb
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby davidb » Sun Jun 26, 2016 11:46 am

Kevin Edwards wrote:As requested, here's the Electron version too - pretty sure this is the final build i used - not checked.

Much the same as the BBC Version, but runs in MODE 5 and has simplified music ( single channel melody ).

Thanks again, Kevin! =D> It's like Christmas in late June! :lol:

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sbadger
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby sbadger » Thu Aug 24, 2017 3:33 pm

In an attempt to get my grey cells working I've just finished porting Kevin's source into RichTW's Beebasm.
I've manged to get it to build with a CRC match when compared to the output when running the original basic assembler routine on Kevin's disc.

I've had a really nice couple of days going through it all and found some interesting things, including some unused\commented out sprites.

Alien11.png
(1.5 KiB) Not downloaded yet

Alien10.png
(1.93 KiB) Not downloaded yet

Alien6 alt.png
(1.28 KiB) Not downloaded yet


(don't know why these aren't inline :S?)


It needs a bit of a tidy but i'll bung it up on git when I get back from holiday.

stew
A3020| A3000x3| BBCBx3 | Electrn | Masterx3 |RiscPC| RPix3
A600 | C64 bbin x2|C64C | Toastrack |QL | XB360&1X |GB |GBC |GBA |GBASP | DS | 3DS XL x2| MD | MS
Atari 7600 | PS1-2-3-4| PSP |Vita |SNES |GC |N64 |Wii & U |Switch |JammaCab |Sony PVMx2

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kieranhj
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby kieranhj » Fri Aug 25, 2017 9:46 am

leenew wrote:Wow!
What other treasures may be lurking on that hard drive Kevin? :shock:

Lee.

Apparently Crazee Rider, according to the Facebook post in the Acorn group at least...
Bitshifters Collective | Retro Code & Demos for BBC Micro & Acorn computers | https://bitshifters.github.io/

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sbadger
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby sbadger » Mon Sep 18, 2017 11:15 am

I've finally managed to push this up to github for anyone interested.


https://github.com/crumbgit/Galaforce


stew
A3020| A3000x3| BBCBx3 | Electrn | Masterx3 |RiscPC| RPix3
A600 | C64 bbin x2|C64C | Toastrack |QL | XB360&1X |GB |GBC |GBA |GBASP | DS | 3DS XL x2| MD | MS
Atari 7600 | PS1-2-3-4| PSP |Vita |SNES |GC |N64 |Wii & U |Switch |JammaCab |Sony PVMx2

paulb
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby paulb » Mon Sep 18, 2017 1:42 pm

sbadger wrote:I've finally managed to push this up to github for anyone interested.


https://github.com/crumbgit/Galaforce


What is the licence of the work? Does GitHub care about hosting potentially non-redistributable software? (Probably not: it drives people to their platform.)

Also, in the README.md file it says...

Read more about the game on it's wiki


This should read "on Wikipedia", being a specific wiki but not specific to Galaforce, of course.

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sbadger
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby sbadger » Mon Sep 18, 2017 5:04 pm

paulb wrote:What is the licence of the work? Does GitHub care about hosting potentially non-redistributable software? (Probably not: it drives people to their platform.)


I'm not trying to infringe anyones copyrights and there are plenty of other examples of buildable retro BBC Micro software on github.
I'd also say Kevin himself posted the BBC Basic assembler version here in this public forum.
Naturally if Kevin wants it removed from github then please PM me.
A3020| A3000x3| BBCBx3 | Electrn | Masterx3 |RiscPC| RPix3
A600 | C64 bbin x2|C64C | Toastrack |QL | XB360&1X |GB |GBC |GBA |GBASP | DS | 3DS XL x2| MD | MS
Atari 7600 | PS1-2-3-4| PSP |Vita |SNES |GC |N64 |Wii & U |Switch |JammaCab |Sony PVMx2

paulb
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Re: Galaforce 30th Anniversary Full Source code for BBC Micro

Postby paulb » Mon Sep 18, 2017 5:41 pm

sbadger wrote:
paulb wrote:What is the licence of the work? Does GitHub care about hosting potentially non-redistributable software? (Probably not: it drives people to their platform.)


I'm not trying to infringe anyones copyrights and there are plenty of other examples of buildable retro BBC Micro software on github.
I'd also say Kevin himself posted the BBC Basic assembler version here in this public forum.
Naturally if Kevin wants it removed from github then please PM me.


I was just asking about whether there is licence information in the repository. If not, even though Kevin (well, "Kevin Edwards" who happened to have the sources, but let us assume it is him) has uploaded the sources here and given permission in a forum post, that doesn't mean it that it makes the status clear to people getting the code from GitHub, and without explicit permissions in the form of a licence, a case can be made that it cannot be redistributed at all.

Other code on GitHub usually has licence information, regardless of whether it is for the Beeb or not. The best outcome here would be Kevin putting some kind of licence on the work, rather than the actual status being unclear.


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