Burnin' Rubber (& what Plus features have really been utilised?)

[Xyphoe]

Hey guys

I've *finally* at last completed Burnin' Rubber and longplay vid recorded (woop)!

Before I record my commentary/review aside from the Plus palette being used really well, has any other notable Plus features been used?

It really looks like 'WEC Le Mans with a lick of paint', but has for example hardware sprites and scrolling been used anywhere? Does that title screen animation use this?
Of course no DMA music/sfx present.

[Devilmarkus]

The "B" and the "R" in the title are build of hardware sprites.
The car is also build of hardware sprites. Also when it rotates or crashes.

Also some CPC+ specific interrupts are used I think.

[andycadley]

Yep, I think extra colours and the hardware sprites for your car and title screen is pretty much it. The PRI gets used to time mode/palette switches on the title screen I think, though nothing particularly exciting.

[MacDeath]

Got to remember that Burnin' Rubber was supposed to fill inside a 128K cartridge alongside Locomotive Basic...

Must be 64K max...?
Perhaps a bit more ?

In the title sequence, isn't the scrolling grey stuff using an Hardware scrolling ?
looks quite smooth.

During game, does the background (horizon) use hardscroll too ?

Anyway, there are not that many plus features to begin with (Palette, few sprites, DMAsounds, interrupts and scrolling )

And the game is quite simple, relying massively on palette changes to get the "night/day" effects...

Also as opposed to Wec le Mans, which include some mode change (interrupt ?)...
Burnin'Rubber seems to use only 16 colours if you remove the player's sprite.

So I don't think there are any raster interrupt (gain of CPU  compaired to Wec le man ?).

There the question : while it looks like Wec le mans (captain Obvious...) does it uses the Wec engine or perhaps Chase HQ engine instead ?

Probably built from scratches from both engines indeed...

[redbox]

Got to remember that Burnin' Rubber was supposed to fill inside a 128K cartridge alongside Locomotive Basic...
Must be 64K max...?
Perhaps a bit more ?

Contrary to what is written almost everywhere on the net, Burnin' Rubber actually uses 64kb + 16kb of the system cartridge, which means it totals 80kb in size.

I found this out when patching the Plus System Cartridge. Banks 4 to 7 AND bank 2 are for Burnin' Rubber, and I think bank 2 holds graphic data.

Looking forward to the longplay video Xyphoe 

[McKlain]

It's funny that they used mode 1 for the car's shadow.

[mahlemiut]

Yep, I think extra colours and the hardware sprites for your car and title screen is pretty much it. The PRI gets used to time mode/palette switches on the title screen I think, though nothing particularly exciting.

From memory, it uses DMA sound for the tyre skidding sound effects.

[andycadley]

It's funny that they used mode 1 for the car's shadow.

Well it's not really "mode 1" because it's the HW sprites, but it's a pretty good effect that ensures the shadow looks right even when passing over the lines or edges of the road. It's not quite as convincing on emulators, since the picture is generally sharper than what you got on a plus monitor or tv.
Rasters are used for mode and palette switches on the title and high score screens, but not in game.

[andycadley]

From memory, it uses DMA sound for the tyre skidding sound effects.

Really? I'd be quite surprised at that, since it's not particularly needed and I'd have thought the dev would've stuck to what he knew for such a simple effect. You have reminded me that it did make better use of stereo sound than most CPC games though, the noise the cars make as you pass them comes from the appropriate speaker. It's particularly good if you wear headphones to play it.

[Axelay]

From memory, it uses DMA sound for the tyre skidding sound effects.

Really? I'd be quite surprised at that, since it's not particularly needed and I'd have thought the dev would've stuck to what he knew for such a simple effect.

Well I dont *know*, but I've always assumed it does myself, since the tyre skidding sound effect is vastly more convincing than every other sound effect in the game, or the skidding sound effects that were used in WEC Le Mans or Chase HQ...

[MacDeath]

It's funny that they used mode 1 for the car's shadow.

Because this makes a fine dithering = good shadow effect.
Could be even better with "mode2" pixel dimensions but... would also use twice sprites = niet !

(unless they had some spare sprites, but I don't think so...)

[cpc4eva]

why do I feel the wec le mans game has better playability ? its just my opinion the wec le mans seems to have better control than burnin rubber - which i find strange as burnin rubber is a plus game whic in theory has better everything at its disposal - in theory


burnin rubber looks great - the colours, shadow of car flipping, background changing from day to night, the tunnel driving and scroll are great but it  feels jerky on the corners and overtaking and only 2 speeds that dont really add much at all to the game.....


Xyphoe did you use the cheats ? its well hard on the time limits is burnin rubber I wouldnt care if you did use the cheats some games need it to stop you getting rsi or swollen wrists or finger cramps....

[sigh]

Played this on my newly acquired plus machine. It doesn't feel as fast as Chase HQ or Supercycle. (Supercycle is the bench mark for me when it comes speed)

I didn't know that the car was built up of hardware sprites.

[Xyphoe]

Thanks for the replies guys!

Yep, I think extra colours and the hardware sprites for your car and title screen is pretty much it. The PRI gets used to time mode/palette switches on the title screen I think, though nothing particularly exciting.

Sorry, what is "PRI"?

From memory, it uses DMA sound for the tyre skidding sound effects.

Wow ... didn't think about that, can anyone confirm this is the case?

Xyphoe   did you use the cheats ? its well hard on the time limits is burnin   rubber I wouldnt care if you did use the cheats some games need it to   stop you getting rsi or swollen wrists or finger cramps....

No I didn't, which is why it has taken me sooo long to do this one. You literally can't crash once or you'll run out of time by the end. I come back and try a recording every few months, it's only taken about 3 years to do this!! At least with other rock hard cart games you have a chance - with Robocop 2 you can use the rooms as restart points and just learn the layout, Navy Seals you can make a little map and follow the same route, etc ... but with Burnin' Rubber basically one bad mistake and forget about it! Especially on the final stages the road is just littered with cars half of which are spinning out ... looks impressive actually and pretty crazy! But almost impossible!

[Xyphoe]

Actually talking of DMA sound, to be honest I'm not really 100% sure what this is precisely. Apart from 'Prehistorik 2 title screen has DMA music'.

I can't find an article on the CPC Wiki describing what this is and how it can be used, only a small mention in the Plus/GX4000 hardware article http://www.cpcwiki.eu/index.php/Plus -

"An automatic DMA transfer system for feeding the sound chip was also added but the sound chip itself remained unchanged"

So.... DMA = Direct Memory Access? I'm guessing?
How does that translate into getting better sfx and music?


ps - does anyone have the .dsk file for this? http://www.cpcwiki.eu/index.php/DMA_Music_Demo

[dragon]

So.... DMA = Direct Memory Access? I'm guessing?

Yes,DMA Is how you programing the ay chip(sound chip).Normally in the cpc(no plus).When you need program sound.Is the z80 processor who sends the instructions to ay chip.Of course this consume cpu time(only 3,5mhz remember).

If  you use dma in the plus series ,the asic of plus send the sound instructions to the ay chip.So If you not use the z80 to generate sound.You no consume the cpu time.So you can use the z80 for other tasks.More sprites for example.

[Xyphoe]

Yes,DMA Is how you programing the ay chip(sound chip).Normally in the cpc(no plus).When you need program sound.Is the z80 processor who sends the instructions to ay chip.Of course this consume cpu time(only 3,5mhz remember).

If  you use dma in the plus series ,the asic of plus send the sound instructions to the ay chip.So If you not use the z80 to generate sound.You no consume the cpu time.So you can use the z80 for other tasks.More sprites for example.

Cool ... so say for example digitised sound effects (perhaps like the screeching noises in Burnin' Rubber) whilst possible to create with a normal CPC the actual sound effect consumes a lot of bytes and CPU cycles? But with DMA it can be fed directly to the AY without needing it pass through the Z80?


But in the case of Prehistorik II title music, even though there's some animated box with text there's nothing much going on so why couldn't the digitized quality music be played on a stock/normal CPC?

[sigh]

On the Rick Dangerous 2 128K Plus remake, that has a digitised scream "in game" which would of been tricky or not possible to have on a CPC. The DMA makes this possible.

(Correct me if I'm wrong..)

[Xyphoe]

Yes, that's what I'm trying to get my head around - more the 'quality' of the sound effect or music.

I understand now that using DMA takes away the CPU overhead which is important for 'in game' ... but say you had a blank static screen with nothing else there - could you not on a stock CPC be able to replicate the same sound effect in RD2+ or the music from Prehistorik II?


(Note - I know digitised music has sometimes been used in normal CPC games, like the Crazy Cars 2 title screen - but it sounds bloody awful!)

[dragon]

Cool ... so say for example digitised sound effects (perhaps like the   screeching noises in Burnin' Rubber) whilst possible to create with a   normal CPC the actual sound effect consumes a lot of bytes and CPU   cycles? But with DMA it can be fed directly to the AY without needing it   pass through the Z80?

I think,burning rubber not uses dma music.

To know if a game uses dma sound or hardware sprites or other feature.Open the cartridge/disk  with win
ape.

When game is running go tu debug->registers.Her you can see with a v if feature is enable.An you can see the hardware sprites if its used.

Yes, with old cpc you can create the same sound as 6128 plus,but only the sound.For example view the voice digitalized of robocop 2 or jet sky simulator.When the cpu is generating the voice, all time cpu is consumed.So the cpc  can't move sprites in screen.When the cpu is liberated,you can play the game.

Here you can read about program the dma(in french).

http://quasar.cpcscene.com/doku.php?id=assem:asic

On the Rick Dangerous 2 128K Plus remake, that has a digitised scream   "in game" which would of been tricky or not possible to have on a CPC.   The DMA makes this possible.

Exactly.You can programme the arghhhh in normally cpc.But,If you program it,you can't move rick dangerous. .

[sigh]

Would this also depend on how many bits are used for the sample? I would of thought that with something like Robocop or Chase HQ, you could probably have the same amount of bits on a Plus for less CPU power. This would enable you to use even more bits for better quality than a CPC.
Both hardware would eventually have to hit a wall at some point on when it comes to sound and the CPC would hit that earlier.

[Xyphoe]

To know if a game uses dma sound or hardware sprites or other feature.Open the cartridge/disk  with win
ape.
When game is running go tu debug->registers.Her you can see with a v if feature is enable.An you can see the hardware sprites if its used.

Attached is a screen shot of Burnin' Rubber registers in game.

Which "v" are you referring to here?

I note "DMA Channel 0" is enabled?


*EDIT*
Just out of interest, below is also the registers for Prehistorik II title   screen. Looks like all 3 DMA channels are utilised (no surprise)
So perhaps then yes Burnin' Rubber is using one DMA channel, perhaps for the tyre screeches!

[andycadley]

Sorry, what is "PRI"?

PRI=Programmable Raster Interrupt. Basically it lets the programmer set which scanline an interrupt should occur on, rather than being limited to the six fixed positions where it normally occurs.

Actually talking of DMA sound, to be honest I'm not really 100% sure what this is precisely. Apart from 'Prehistorik 2 title screen has DMA music'.

Strictly speaking it isn't 'DMA' or at least not in the traditional sense. In the plus, what you actually have is a kind of mini-processor that is capable of running little 'programs' which can do a limited range of things like send data to the sound chip or generate interrupts. It's particularly useful for things which would normally be very CPU intensive like playing back sampled sounds.

ps - does anyone have the .dsk file for this? http://www.cpcwiki.eu/index.php/DMA_Music_Demo

I definitely did have at one point, if nobody can point you in the direction I'll have a dig around and see if I still do.

[dragon]

Yes,The sound always is limited by the sound chip(it's the same in plus and not plus).And The dma is limited,but now I not know the limit of dma+ay vs ay+z80.

Made dma for plus series,is the mode of alan sugar to reduce cost.You not change the cpu to a expensive cpu=computer more expensive but the price of the asic is the same with or without dma. And the cpc updates with more speed.


In prehistorik 2.All dma channels is used in the presentation screen.But in game it uses the dma channel 0 only but uses it.

I not sure,but maybe it use the extra power to create the mountain of backgrond.

This is a example of dma,It run in maxam 1.5: (copy and paste in maxam).

http://quasar.cpcscene.com/lib/exe/fetch.php?id=assem%3Aasic&cache=cache&media=assem:asic_dma.asm

[Xyphoe]

So wait.... the "DMA" is not *just* useful for sound, but can be used for other processing features and sub-routines, etc?

I think I may finally be grasping this.

ie even though DMA Channel 0 is enabled in Burnin' Rubber it isn't necessarily being used for the screeching sound fx?

Also so when people refer to the 'DMA' it is actually a real chip inside, which has 3 channels that come from where and go to where exactly?