PeteD Posted March 3, 2010 Share Posted March 3, 2010 (edited) Couldn't sleep last night so I started hacking at some Beeb code (not done any coding on the beeb since about 84-85 so couldn't remember much) but I managed to get Arcadians running on A8. Is it worth continuing? The title/options screen works and so does the game (see Youtube vid snippet) so it just needs the sprite drawing etc rejiggered (as you can see, it's all crapped up due to the screen mode difference on BBC to A8), sound (working on that now) and some other bits and bobs doing. *edit* Could've done with a longer vid really but I was expecting it to result in a ridiculously large file so I cut it short saving from the emu. Oh well, it's all much the same, see some aliens peel off, then get back in formation and occasionally pause then redraw when your guy has been killed. *edit 2* Link to the . Should work ok on A8, 4 colours, screen is a bit tall I think but I can re-jig some of that. Pete Edited March 3, 2010 by PeteD 2 Quote Link to comment Share on other sites More sharing options...
frogstar_robot Posted March 3, 2010 Share Posted March 3, 2010 Couldn't sleep last night so I started hacking at some Beeb code (not done any coding on the beeb since about 84-85 so couldn't remember much) but I managed to get Arcadians running on A8. Is it worth continuing? The title/options screen works and so does the game (see Youtube vis snippet) so it just needs the sprite drawing etc rejiggered (as you can see, it's all crapped up due to the screen mode difference on BBC to A8), sound (working on that now) and some other bits and bobs doing. *edit* Could've done with a longer vid really but I was expecting it to result in a ridiculously large file so I cut it short saving from the emu. Oh well, it's all much the same, see some aliens peel off, then get back in formation and occasionally pause then redraw when your guy has been killed. Pete It seems to animate smoothly enough. This could turn out to be a nice little shooter! 1 Quote Link to comment Share on other sites More sharing options...
GroovyBee Posted March 3, 2010 Share Posted March 3, 2010 Just out of curiosity are BBC micro games easy to convert to Atari machines? Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 3, 2010 Author Share Posted March 3, 2010 Just out of curiosity are BBC micro games easy to convert to Atari machines? So far I just wrote some replacements for ROM calls, loaded the main file into ram in the correct place, called it's start address, fixed some issues with it getting stuck waiting for things (more ROM functions) and then for it's current state (why the graphics are fairly messed up atm) drew chars 0-127 (actually 0-255 cuz I was 1/2 asleep) on a screen and pointed charbase at the area of beeb ram it draws to in the mode the game uses. Of course now it needs to draw in a way the A8 can handle but I've already found the code for the sprite draw etc and can quite easily alter it. Then there's things like MODE7 screens being able to display more colours and using control codes (used for the title/options screen on Arcadians) so that'll have to be re-written or hacked to display an A8 version but that should be fairly easy too. Pete 2 Quote Link to comment Share on other sites More sharing options...
ivop Posted March 3, 2010 Share Posted March 3, 2010 Just out of curiosity are BBC micro games easy to convert to Atari machines? I just wrote some replacements for ROM calls, [...] (more ROM functions) [...] Perhaps you could turn that into a little library? 1 Quote Link to comment Share on other sites More sharing options...
Wrathchild Posted March 3, 2010 Share Posted March 3, 2010 Similar experience here with Elite but sadly something fun like Tetrapod didn't work because of the higher rez the beeb can do. 1 Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 3, 2010 Author Share Posted March 3, 2010 (edited) Just out of curiosity are BBC micro games easy to convert to Atari machines? I just wrote some replacements for ROM calls, [...] (more ROM functions) [...] Perhaps you could turn that into a little library? That's my intention It won't do everything for you but a lot of games use the ROM calls for doing a fair amount of stuff such as changing video modes, reading keys, playing sounds/music, timing, etc It's been easy to do because they all vector through $FF?? so I shoved some of my own vectors into A8 RAM in the same place and then have a jump table to go to the correct code (presumably how the Beeb one works because each vector can do different things based on the input registers). *edit* So far this is untouched Beeb code. Straight from the file ripped off the disk image. Not disassembled yet so it bodes well for getting other things running rapidly but then you've got to trace through code and hack things to change anything so it's not always the best option. Pete Edited March 3, 2010 by PeteD 2 Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 3, 2010 Author Share Posted March 3, 2010 Similar experience here with Elite but sadly something fun like Tetrapod didn't work because of the higher rez the beeb can do. Yeah, Arcadians surprised me by how simplistic most of it is. I just chose it because it was always one of my faves back when I owned a Beeb. It starts getting a lot harder depending on resolution, use of complex interrupts, direct access to hardware etc. Something like tetrapod you'd have to just rewrite the draw routines to a lower res. I think Arcadians is doing some dodgy crtc shifting hence in the vid I uploaded the sprite definitions jiggle around a lot instead of just moving left/right so that'll have to be rewritten. Pete 2 Quote Link to comment Share on other sites More sharing options...
Wrathchild Posted March 3, 2010 Share Posted March 3, 2010 Tetrapod could be a good candidate/excuse for me to cut my teeth on VBXE programming but should find and fix that bug in Elite first! Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 3, 2010 Author Share Posted March 3, 2010 Tetrapod could be a good candidate/excuse for me to cut my teeth on VBXE programming but should find and fix that bug in Elite first! Great idea VBXE neeeeeds Tetrapod!! Pete 2 Quote Link to comment Share on other sites More sharing options...
Kr0tki Posted March 3, 2010 Share Posted March 3, 2010 Pete, have you contacted Xxl? He has already converted a few games from the BBC (Hobgoblin, Knight Lore) and might help. 1 Quote Link to comment Share on other sites More sharing options...
José Pereira Posted March 3, 2010 Share Posted March 3, 2010 Just out of curiosity are BBC micro games easy to convert to Atari machines? I just wrote some replacements for ROM calls, [...] (more ROM functions) [...] Perhaps you could turn that into a little library? That's my intention It won't do everything for you but a lot of games use the ROM calls for doing a fair amount of stuff such as changing video modes, reading keys, playing sounds/music, timing, etc It's been easy to do because they all vector through $FF?? so I shoved some of my own vectors into A8 RAM in the same place and then have a jump table to go to the correct code (presumably how the Beeb one works because each vector can do different things based on the input registers). *edit* So far this is untouched Beeb code. Straight from the file ripped off the disk image. Not disassembled yet so it bodes well for getting other things running rapidly but then you've got to trace through code and hack things to change anything so it's not always the best option. Pete Hello. Now I'm here. What I have to say about this and all "Beeb" Games: A good, good example is Hobgoblin. Almost all are in Bitmap mode 4colours. Here it's a straight port. But from Hobgoblin you can see that with DLIs. you can have more 4colours in diferent lines(Game Name/Logo/Status Panel). And you can enter in CharMode and have 5th colour. Now if just have your Player with PM0/1 in multicolour (3colours on it) you'll get almost all "Beeb" games in Polish old times way (and stil not using PM2/3). In this game particular, if you want my opininion I would get our Ship as PM0/1/3rd colour and use PF3 for the bullets (Possible?). Also a DLI. to the Scores will give different colours there. I'm trying to remember the name of a game on BBC that was the only one I remember that uses something like a ColourMap (Does BBC have?). Soo, wait a minute, don't go away :? :? :? It was also converted to C64 and the BBC was better looking (colours,...). A Diving game... What was the name Are you still here? Oh! I found it: Exile (exile.zip) Another one that I think it was a very high atandard for the BBC general type of games was Strykers Run (with some speed it would look very neat on A8).strykers-run.zip Not helped in anything but I need to change from Xenon into something different, and PeteD you're the choosen one. Bye.... José Pereira. Quote Link to comment Share on other sites More sharing options...
carmel_andrews Posted March 3, 2010 Share Posted March 3, 2010 Pete...b4 you go to sleep tonight, don't forget to let the code fairies in, they'll finish of the game for you (dunno why you didn't do that first of all) 1 Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 3, 2010 Author Share Posted March 3, 2010 Pete, have you contacted Xxl? He has already converted a few games from the BBC (Hobgoblin, Knight Lore) and might help. No real need atm. I cut my teeth on the BBC, learned 6502 on it and did some simple demos (scrolling messages rotating through chars etc) before I owned a C64 and it's all coming back to me So far the game is all running correctly without touching any of the original code, it just needs the sprite routine changing to draw in a more A8 friendly way (there are other ways around the problem but that will be best) and I know exactly what's needed there, some of my ROM code finishing/rewriting to work properly and it's pretty much done. Pete 2 Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 3, 2010 Author Share Posted March 3, 2010 ahaa! Doesn't help when I don't remember properly what the screen format was. Now I know exactly why it looks so odd in the vid so there's either some data changing to do or a lookup table to alter the data at runtime. First option is fastest and as I know where the sprite code etc is I can find the data from that and run a conversion pass on it then alter the drawing code to work to A8 screen addresses, that should have most of the drawing fixed Pete 2 Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 4, 2010 Author Share Posted March 4, 2010 Day 2 progress Seems a frame or two got missed with my data jiggling code, odd, I'll no doubt have to track down where they're hiding. Screen still looks all wrong but thats because it's just a screen full of char 0 with 0-255 (yeah still 255) at the top and pointing CHBASE to some interesting part of the beeb bitmap. Pete 2 Quote Link to comment Share on other sites More sharing options...
Mclaneinc Posted March 4, 2010 Share Posted March 4, 2010 Looking good Pete 1 Quote Link to comment Share on other sites More sharing options...
xxl Posted March 4, 2010 Share Posted March 4, 2010 wow, nice... but there is a lot game like that on a8... Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 4, 2010 Author Share Posted March 4, 2010 wow, nice... but there is a lot game like that on a8... Yeah, like this one I haven't done it because I think the A8 needs more Galaxian clones, despite quite a few people requesting one recently. I just did it because I couldn't sleep (hence the topic title) and was thinking about what would be involved to do something like this. So far I've done about 6 hours work on it so it's not exactly been a waste of time or anything (even if I stopped now I've still enjoyed doing it) and I've now got the start of a Beeb "library" and some other games I've tried quickly today are already running to various stages so in the long run it could be a very useful thing Pete 2 Quote Link to comment Share on other sites More sharing options...
xxl Posted March 4, 2010 Share Posted March 4, 2010 patch $ffee; $fff1; $fff4 and go! i dont remember what x=$ef or x=$ae and a=$81 when jsr $fff4 but game run ok arcadians.zip 2 Quote Link to comment Share on other sites More sharing options...
xxl Posted March 4, 2010 Share Posted March 4, 2010 yes... but maybe something really funny - repton, repton3.. all reptons..., exile this is bbc micro very best games and very playable Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 4, 2010 Author Share Posted March 4, 2010 (edited) patch $ffee; $fff1; $fff4 and go! i dont remember what x=$ef or x=$ae and a=$81 when jsr $fff4 but game run ok Yeah, that's basically what I'm doing but just patching those wouldn't produce what you have in the vid, so did you alter the drawing routines or do you read the beeb screen and redraw it in A8 format? Something that takes more CPU. I'm trying to make something now that is fairly generic for porting A8 stuff Remember, this is 6 hours work and for fun but if you want to piss on it then ok. Obviously us outsider c64 freaks are wasting our time eg I love the way you immediately get a + click and I get none So I may as well give up.. *edit* eg, using the same code... atarivid.zip Alien 8. 10 mins work. Once the screen DLI stuff is done then I can also either do the convert beeb screen to A8 one or find/hack the beeb draw routines. Pete Edited March 4, 2010 by PeteD 4 Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 4, 2010 Author Share Posted March 4, 2010 lol no need to get carried away with the + button I was just making a point that some guys here are into games, some guys it seems to be politics. Pete 3 Quote Link to comment Share on other sites More sharing options...
xxl Posted March 4, 2010 Share Posted March 4, 2010 hmmm, > Yeah, that's basically what I'm doing but just patching those wouldn't produce what you have in the vid about 2 years ago i wrote translator for bbc game and yes all you need is patch some adres... http://atari.pl/thrust.rar and yes, this is rather easy to convert bbc micro games... all you need is choice right game... so if you want arcadians ok, but many people (i think) prefers ... i dont know... repton like games :-) Quote Link to comment Share on other sites More sharing options...
PeteD Posted March 4, 2010 Author Share Posted March 4, 2010 Just to point out to xxl, I'm not mad or anything, just seems a bit crap for you to have posted a video of Arcadians that uses a different method to drawing the screen to the one I was going to take and you've had a lot more beeb to a8 porting experience than me. It just seems like now it's pointless me carrying on as it's already been done.. Pete 2 Quote Link to comment Share on other sites More sharing options...
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