New version of New Rally-X for the BBC Micro

[tricky]

Here is the demo with the 4 voice version, slowed down by extending the longer of the pairs of notes and started earlier, so that it finishes just before the main background music starts. You can also play as many rounds as you like, but still can't die!

[oss003]

Just tried it ....... sounds great ... not to fast anymore, just right.
But I think you need a sound on/off option because if you listen 10 minutes to the tune, it stays in your head the whole day long .......

Greetings
Kees

[tricky]

Maybe I'll add a premium subscription DLC option to turn the sound off, only £9.99 a month

[Arcadian]

Nice, just had a quick go,played through a few rounds. Intro and main theme are sounding good - I like the tune so I don't find it annoying!

The game seems nice and responsive, but I shudder to think how I'd have fared without being impervious!

[tricky]

Well it has the max cars and max rocks which is something like level 16 plus bonus rounds and you don't have smoke.

How do people feel about calling it "Micro Rally-X"?
The micro is from micro machines (top down zoomed out) as well as micro-computer. Rally-X is so you know what it is and can be searched easily.

[chrisn]

Just tried your latest update, and the music is a lot better! I like Micro Rally-X for the title

[oss003]

Maybe 'Beeb Rally-X'

Greetings
Kees

[MartinH]

Wow, this is coming along really nicely!

Hope we'll be able to play it in the HSC at some point.

[tricky]

So I have to get good at it before release

[tricky]

I have added colour cycling to the maps at great personal risk to my eyesight and anyone who tests it
There are 36 colour combinations before it cycles!
I'm not happy with the levels where it is red or magenta cars on a magenta or red background or white/yellow on yellow/white. They looked OK on the enlarged image, but are not easily visible on a more reasonable screen size. I have kept the tyres, rock outlines and flags outlines black on all levels, so that they can always be seen, even if your eyes are more sensitive to some colours than others.
If there are any levels where you cannot makeout which bits are road, please send me a screenshot so that I can remove that combination.
I would like to keep as many combinations as possible, but I would rather it be playable by all.

Keys: Z X / :
You need to collect all 10 flags to get to the next level/colour combination - you still can't die!

PS Beware ear worms

[oss003]

I think the worst case is a RF CRT TV ...... or composite video monitor.
You can test the visibilty on those.

Greetings
Kees

[tricky]

I think the worst case is a RF CRT TV ...... or composite video monitor.
You can test the visibilty on those.

Greetings
Kees

Didn't I mention that I don't support RF, Composite or LCDs other than via a PI:RGB2HDMI
All those crawling dots on RF give me the creeps!

[oss003]

Didn't I mention that I don't support RF, Composite or LCDs other than via a PI:RGB2HDMI
All those crawling dots on RF give me the creeps!

OK ..... problem solved ......

Greetings
Kees

[Steve8bit]

Glad you're working on this one. I have a lot of love for New Rally X due to the fact I met my wife in an Arcade in the 80's and she was playing the game and dancing to the music at the same time. haha Personally I've never been able to do more than 3-4 levels but yeah, it's got a place in my heart for the above reason.

Good luck with the game and I can't wait to try it out on my real Beeb ..when it arrives!

[tricky]

I've been adding a few little bits, doing well on memory, but still a lot of bits to add and the Challenge screen is looking a little sparse!
3,174 bytes free plus 3 more in ZP.
I've never had this much free memory at this point, well, briefly in space invaders before I filled it with samples!

TODO:
you hit nme + ignore at start (currently ignored the whole time!)
you hit rock
engine sound - maybe attenuation = dist to nearest nme
smoke: fuel, tile, dissipating
nme hit smoke
nme hit rock
nme avoiding rock
nme hit nme
nme avoiding nme
nme hit you
check for nme speed and acceleration over levels
lives and game over
high-score + tune
attract mode
challenge stage summary
possible intermission!

All feedback welcome

[cardboardguru]

Looking good Tricky. Was the reason for the redesign that you can't do good horizontal hardware scrolling on Mode 1?

[tricky]

Sort of, this is what it looks like, well, better really as the recording has some issues.

Watch in 720p50 https://www.youtube.com/watch?v=XeT-Y0tgtho
If you run the attached disc image on b-em, you should get what it is like on a CRT (or run it on a CRT ) but if you run it on beebem (without my hacks) you will get what it looks like on an LCD! AFAIK, beebfpga, MiSTER, PI:RGB2HDMI, CRTs and all emulators except beebem support it.

This is the same method as I used BITD, but my code wasn't fast enough at the time to stop the edges of the screen juddering.

My Pac Land demo uses the same technique, but makes the screen wide enough to not see the juddering on the edges

Watch in 720p50 https://www.youtube.com/watch?v=FUb1wUC44GE On the PacLand demo, you can see why I don't like MODE 2 for slow scrolling (and Pac Man doesn't has a walk anim) - hold SHIFT for run.

Which is why if I ever do an R-Type type game, it will be mode 1.

Watch in 720p50 https://www.youtube.com/watch?v=qZutBb3bCqw
The coloured horizontal lines are to check timing and are how long each of the four differently rendered frames takes, starting at the top of the screen. SO, one takes about 40 scan lines (about 48 worst case), one 32 and the other two less than 8, this is out of 312 per frame, so loads of time left for a game
In the demo, you can see the left hand side juddering until it gets to the left hand side of the screen, where I deal with it

[cardboardguru]

I'm on a Mac so I can't run b-em at all, and BeebEm 5 runs at about 1fps. And my actual Beeb is in pieces awaiting me soldering in replacement caps. So I literally can't see the issue.

Is it that at 50fps Mode 2 scrolling is going by too fast for most games? 80 CRTC chars means the whole screen goes by in about a second and a half. Or is there some sort of artifact that makes it ugly?

[tricky]

It is varying the h-sync pulse width to get 160 steps instead of the 80 characters.

You should be able to use jsbeeb to try it out, or b2 or beebjit (I can't remember which work on a Mac).

The ugly bit is in Pac Land without SHIFT pressed when it goes at 25 fps, ignoring the really ugly bit that Pac Man has the wrong animation frames.
This is basically one MODE 1 pixel per frame, which can't be done in HW so it has to move the MODE 2 image every other frame.

The R-Type demo has two copies of the screen offset by one MODE 1 pixel from each other and then varies the h-sync pulse to move them two MODE 1 pixels, giving the four pixel offsets require to get you to the next 6845 R12/13 character.
There is an explanation in this post.

[cardboardguru]

Thanks Tricky. A very interesting thread you linked to. I really hadn't realised there were so many problems with scrolling. When I saw Planetoid, BITD, I kind of assumed that hardware scrolling was just something the Beeb hardware was capable of.

I just tried loading Planetoid up in b2 to see whether it is using hardware scrolling at all, intending to use the debug feature that tells you what memory address is responsible for the pixel the mouse pointer is pointing at. But disappointingly it seem that b2 can't run Planetoid. It freezes after drawing the scanner outline and landscape.

One of these days I'll try my hand at a scrolling game, and see all these problems first hand.

[tricky]

That surprises me about planetoid on b2, was it in master mode? I don't know if that would make any difference
beebem and b-em both have options to show the 6845 registers and as there is no vertical rupture, I think that they will always report the start address.

You can have scrolling without hardware assisting


https://youtu.be/MeoxDQOS-iM best watched in 720p on a 50Hz monitor.


https://youtu.be/cvoTZyCKWhU best watched in 720p on a 50Hz monitor.

[cardboardguru]

No, it was in B+ mode. But since you asked, I've gone through all modes and it's the same. The disk works OK on JSBeeb though, so it's not a bad copy.

Yes, scrolling is possible without hardware. I just imagined that Planetoid was probably doing hardware for the greater part of the screen - The playfield with the terrain and most of the sprites. And then drawing the scanner area to match, because there's so much less there to draw.

OK, I thought the only way to be sure is to check code. Luckily someone's disassembled Planetoid. Sure enough it does hardware scrolling.

Code: Select all

scroll_scrn:lda		_originp_l
			sta		_oldorgp_l
			lda		_originp_h
			sta		_oldorgp_h

			lda		_xrel_l
			asl					;-> cells
			lda		_xrel_h
			rol		
			pha					;-> xwin
			sec		
			sbc		_xwin
			sta		_dxwin		;(x 2px)
			asl		
			asl					; *= 8	
			asl					;screen
			ldy		#0			;bytes
			bcc		+
			ldy		#$ff		;(signed)

+			sta		_scrolloff_l ;22ec
			clc		
			adc		_originp_l
			sta		_originp_l
			tya					;00/ff
			sta		_scrolloff_h
			adc		_originp_h
			bpl		+
			sec		
			sbc		#$50		;wrap vram
+			cmp		#$30		;22fd
			bcs		+
			adc		#$50
+			sta		_originp_h	;2303
			pla		
			sta		_xwin
			jmp		screenstart
			;rts

-----------------------------

;$1ef7,+27	14loc
;Write new video RAM origin to 6845 R12/13
;	arg:	_originp
;void		screenstart(void *originp);
screenstart:lda		_originp_l	;new
			sta		_temp		;screen
			lda		_originp_h	;origin
			lsr		
			ror		_temp
			lsr	
			ror		_temp		; / 8
			lsr		
			ror		_temp
originout:	ldx		#12			;reg 12,13
			jsr		out6845		;screen
			ldx		#13			;start
			lda		_temp		;addr >> 3
			jmp		out6845
			;rts

[tricky]

I guess the ground is quite expensive then, or at least with all the sprites as well.

[tom_seddon]

I just tried loading Planetoid up in b2 to see whether it is using hardware scrolling at all, intending to use the debug feature that tells you what memory address is responsible for the pixel the mouse pointer is pointing at. But disappointingly it seem that b2 can't run Planetoid. It freezes after drawing the scanner outline and landscape.

Thanks for the report. At least one version of Planetoid did work at some point, as it was improved by fixing some VIA issues: https://github.com/tom-seddon/b2/commit ... 77def716a4

I've added an issue to track this: https://github.com/tom-seddon/b2/issues/153

--Tom

[cardboardguru]

Thanks for the report. At least one version of Planetoid did work at some point, as it was improved by fixing some VIA issues: https://github.com/tom-seddon/b2/commit ... 77def716a4

I've added an issue to track this: https://github.com/tom-seddon/b2/issues/153

Ah, thanks Tom. I should have thought to report it myself. The specific version of Planetoid that has the problem is The one downloadable from here:
http://bbcmicro.co.uk/game.php?id=11

And I'm running b2 on a Mac Pro with Big Sur.

I'll go and comment with the same info on the issue.

[tricky]

Small update, now with smoke and enemy cars spinning out when going through smoke, hitting rocks or eachother.
You still can't die/collide with rocks or the enemy cars.
High score works, but as you can't end a game you can't test that!
I need to add a new sound encoding to get the hi-score music in or optimise a few tunes!

2905 bytes free plus 2 in ZP, so more room than enthusiasm to improve things like the Challenge stage screen!

I'm happy for people to suggest new graphics or features, just no promises on whether I include them

Z X : / RETURN (smoke - uses fuel) ESCAPE (quit cleanly)

As you might be able to tell, I'm struggling to finish this one - again!

TODO
you hit nme + ignore at start
you hit rock
engine sound - maybe vol = dist to nearest nme
nme avoiding rock
nme avoiding nme
nme hit you
check for nme speed and acceleration over levels
lives and game over
high-score tune
attract mode
better challenge stage summary
possible intermission!

[fwibbler]

Well its all looking good so far. The game plays well.

I noticed on the third level (right after the intermission screen) the 5 enemy cars that appear at the start just sit there and don't move after you. (Which makes for a nice easy to finish level!)
I've attached a screen shot...

[tricky]

That is intended, it is the "Challenge Stage" where the cars don't move until you run out of fuel.
I do need to check that my fuel consumption matches the arcade (I think it does to start with, but haven't checked later levels).
Matching is a little tricky as they have 12 frames at 60 fps to move one "block", while I have 8 frames at 50fps.

[Arcadian]

Just played through loads of screens, looking really slick Tricky!

I do like the music, but I'm wondering if it could benefit from being played back at a quieter volume than the sound effects e.g. maybe -10 instead of -15?!

[tricky]

Thanks Arcadian.
The background music should be at -7, fuel is at -5, round clear at -7, flags are -7 and game start -14 (I think) and -7.
But I can hopefully easily make the tune louder (it will take a bit more memory, but I have plenty).