Ghosts'n Goblins for Amstrad PLUS 128K [PREVIEW]

Started by Golem13, 23:21, 09 April 20

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

BSC

It looks fantastic! I don't mean to being overly critical, but I am sincerely wondering why the scrolling (at least in the video) is not as fluid as one would expect it from the ASIC .. I am referring mainly to the horizontal scrolling, looks like it is at 25 fps ..

kawickboy


Golem13

Quote from: kawickboy on 13:50, 25 November 21Any physical release planned ?

Yes, if there are fans, it is likely that we will make a physical collector's version. In any case, technically we have the possibility.

Golem13

#103
Quote from: BSC on 19:38, 23 November 21
It looks fantastic! I don't mean to being overly critical, but I am sincerely wondering why the scrolling (at least in the video) is not as fluid as one would expect it from the ASIC .. I am referring mainly to the horizontal scrolling, looks like it is at 25 fps ..

You are absolutely right, the game is at 25fps. It can run 90% of the time at 50fps, but there are still 10% of the time, in given situations, where it would go down to 25fps. Having experienced it, these slowdowns are quite unsightly and unpleasant. So we decided to set it permanently at 25fps and keep this speed in 100% of the cases.

To come back to the asic, it allows things that a classic Amstrad doesn't allow, like hard scrolling at pixel/line, PRI interrupts, hardware "rupture", 16 hard sprites with their palette of 15 inks unbundled from the mode as well as a range of 4096 colors, and 3 DMA to drive the sound chip. This is good, of course very usefull. It helps with some things, but that's all.

The hard scrolling of the CPC classic, apart from the fact that it is done at word (without tricks), is as fast as what the asic offers. All the software handling of a hardware scrolling is still done by a Z80 at the same speed as a CPC. Also, the hard sprites have a non-indexed by a pointer buffer that has to be filled in software. This is certainly more efficient than a soft sprite, but it is not CPU free. Also I'd like to point out that the game has a lot of soft sprites in addition to the 16 hard sprites animated on the screen, a multidirectional horizontal and vertical scrolling as well as music and sound effects.

You have to understand that a game invented for a machine will be made of sequences that do not exceed the capabilities of this machine.
When you reproduce a game made for another hardware, on an Amstrad PLUS, you will find a lot of situations that will not be easy to manage correctly.
This is the case in many situations with Ghosts'n Goblins, like many adaptations.
Of course an Amstrad CPC can't do this in the same way, that's for sure. But I think that permanent 25hz, considering the gameplay of the original, what we did with it and what an Amstrad PLUS can offer, is a good result.

JayBlood

Quote from: Golem13 on 15:19, 25 November 21
Yes, if there are fans, it is likely that we will make a physical collector's version. In any case, technically we have the possibility.
Great! :) :)
Jay

BSC

Quote from: Golem13 on 15:44, 25 November 21All the software handling of a hardware scrolling is still done by a Z80 at the same speed as a CPC. Also, the hard sprites have a non-indexed by a pointer buffer that has to be filled in software. This is certainly more efficient than a soft sprite, but it is not CPU free.

Thanks for your elaborate response, especially the quoted part was not obvious to me (even though it should have), as I said: it looks awesome and I was just wondering. Looking forward to the final release. Keep it up!

amijim

We have all enjoyed the one level promo demo and wait for the final release but please consider about a Ghouls and ghosts remake.Have you even consider of a sequel for our belove plus.thank you for your effort and your communication.

lmimmfn

Quote from: amijim on 23:43, 12 December 21
We have all enjoyed the one level promo demo and wait for the final release but please consider about a Ghouls and ghosts remake.Have you even consider of a sequel for our belove plus.thank you for your effort and your communication.
Honestly, let the man finish his current project
6128 for the win!!!

Golem13

Quote from: amijim on 23:43, 12 December 21
We have all enjoyed the one level promo demo and wait for the final release but please consider about a Ghouls and ghosts remake.Have you even consider of a sequel for our belove plus.thank you for your effort and your communication.


Ahaha, I can think about it, "ça ne mange pas de pain" as they say in French :) which means that it doesn't cost much to just think about it. Yes let's finish this one first. The second one is a bit more technically challenging, and would require bigger compromises.

Golem13


Here are the three images I made public on 10 December from mid level 2, with the following caption, again recalling a part of our youth : As you lead an expedition to free your beloved, the icy winter calm of the polar regions you have just traversed is disturbed by a terrifying phenomenon. Where does this deluge of growling come from? Who commands these supernatural forces? How can they be stopped? The one who must answer these questions is YOU.


Captured with an IPhone on a CRT
May be a cartoon


Captured on an emu
May be a cartoon


Captured on another emu with Roudoudou's personal filter
May be a cartoon

Gryzor


amijim


zeropolis79

Looking very nice!


In theory, could the game engine be used to remake Ghouls N Ghosts?

ralferoo

Wow, this looks amazing!

Just wondering though if this is technically possible on a 464+ rather than requiring a 6128+ (presumably anything that's stored in the extra 64KB of RAM could be stored instead on the cartridge) or does it really need all the RAM?  I can certainly imagine it might be convenient to double buffer the screen and use 32KB for each, but if you're making heavy use of the sprites, I'm not sure if you would bother double buffering as well.

That said, I'm probably missing a subtlety of plus programming (I guess cartridge is only mappable to top and bottom 16KB banks?) as I've never tried coding for anything other that the base 464 as it's what I had as a kid, so it's what I'm most fond of.

nanrc20

¡Enhorabuena!

�Es maravilloso que se pueda por fin aprovechar
 las capacidades de la gama +, ya que la industria en su día se lo negó.

Me gustaría preguntarte que parte programaste en ensamblador...cual en C y que instruccion en concreto activa el scroll hardwsre y sprite por hardware.


Gracias por vuestro trabajo.



CraigsBar

Having just installed the 2nd 64k ram bank in my GX4000 I can confirm it works flawlessly on a GX4128k . Hopefully the full game won't take another 4 years as I love this under emulation already. brilliant work @Golem13 simply breathtaking.
IRC:  #Retro4All on Freenode

Bug Powell

why not having done a crtc adaptation to make it working on all cpc? in 2022, all cpc demos and games should work on all cpc models!

andycadley

Quote from: Bug Powell on 12:42, 30 March 22why not having done a crtc adaptation to make it working on all cpc? in 2022, all cpc demos and games should work on all cpc models!
All Plus machines have the same CRTC and anything that uses the Plus hardware extensions isn't going to work on an old school CPC.

Bug Powell

#118
i have read that some old cpc (not plus) are equiped with an asic chip. so why did golem13 make the effort to make his game working on this type of cpc?

andycadley

Quote from: Bug Powell on 13:07, 30 March 22i have read that some old cpc (not plus) are equiped with an asic chip. so why did golem13 make the effort to make his game working on this type of cpc?
It's an ASIC, in a strictly technical sense, just one that only implements the functionality of the old CPC models.

The ASIC in the Plus is a whole different beast that adds hardware sprites, scrolling, 4096 colours, DMA sound etc.

When CPC folk talk about the ASIC, they're usually using it as shorthand for the Plus version.

Bug Powell

thank you for your clear answer! too bad that i do not own a cpc plus. i will play it on an emulator.

TotO

The last "low cost" CPC produced are using the pre-ASIC that include the same CRTC than the Plus but not the dedicated features. It is called CRTC4 because it was discovered after the Plus ASIC called CRTC3.

The pre-ASIC include the GA, the CRTC and some glue logic to save parts and simplify the mainboard tracks rooting by removing the need to expose the video data and address buses. It doesn't include the PPI and the AY (neither the ASIC) as sometime wrote.

Sure, we was able to expect it to have hidden future features like 12-bit palette, but... no.
https://www.cpcwiki.eu/imgs/8/8e/CPC464_PCB_Top_%28Z80329_MC0099A%29.jpg
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

eto

Quote from: TotO on 14:37, 30 March 22The pre-ASIC include the GA, the CRTC and some glue logic to save parts and simplify the mainboard tracks rooting by removing the need to expose the video data and address buses.
just out of curiosity: it's the same ASIC as in the cost-down 6128, right? Would it be possible to upgrade to 128K internally as the ASIC includes the PAL? E.g. populating the 41464 sockets and wiring CAS to CAS1?

TotO

As I know, yes you can enable the PAL include into the pre-ASIC and upgrade like a real 6128.
"You make one mistake in your life and the internet will never let you live it down" (Keith Goodyer)

Powered by SMFPacks Menu Editor Mod