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General Category => Programming => Topic started by: steve on 15:42, 13 June 13

Title: what good are the plus features?
Post by: steve on 15:42, 13 June 13
The Phortem demo shows a CPC and a PLUS apparently doing (almost) the same thing.

Maybe the plus features were not really exploited so that the CPC could keep up?

So can anyone imagine a game using all the plus features that could not run on the CPC or at the same speed?

The sound DMA and sprites should mean more CPU time for other things, but how much time would be saved?, is it enough to make a much more complex game?
Title: Re: what good are the plus features?
Post by: arnoldemu on 16:04, 13 June 13
The Phortem demo shows a CPC and a PLUS apparently doing (almost) the same thing.
Phortem only uses the plus colour palette I believe, it doesn't use other plus features.
Title: Re: what good are the plus features?
Post by: steve on 18:09, 13 June 13
Yes, that's what I thought, but it set me wondering if the plus features would really make that much difference, do they make up for not having a 16 bit processor?
Title: Re: what good are the plus features?
Post by: steve on 18:19, 13 June 13
If a game used a standard graphics mode, could the plus hardware put text or small graphics in the border without using overscan?

I am thinking here of startrek's viewscreen which has a few numbers below the screen IRC.
Title: Re: what good are the plus features?
Post by: TFM on 18:21, 13 June 13
For a much more complex game you'll need:
- 4 MB of RAM
- 20 MB (or more) of hard-disc space
- and maybe a ROM card
 
The Plus features add new things, may speed up things, but don't allow necessarily to make bigger / more complex games.
Title: Re: what good are the plus features?
Post by: steve on 18:22, 13 June 13
For a much more complex game you'll need:
- 4 MB of RAM
- 20 MB (or more) of hard-disc space
- and maybe a ROM card
 
The Plus features add new things, may speed up things, but don't allow necessarily to make bigger / more complex games.

So you are saying they are totally useless?
Title: Re: what good are the plus features?
Post by: steve on 18:24, 13 June 13
For a much more complex game you'll need:
- 4 MB of RAM
- 20 MB (or more) of hard-disc space
- and maybe a ROM card
 
The Plus features add new things, may speed up things, but don't allow necessarily to make bigger / more complex games.

You've gone overboard there just a bit, just add a 512KB cartridge and maybe 128KB ram.
Title: Re: what good are the plus features?
Post by: TFM on 18:35, 13 June 13
So you are saying they are totally useless?
No. Not at all. I was answering regarding complex games (and 128 KB RAM is really not enought, I have serious trouble with that with some of my games...).
The Plus features can make things more beautiful, sound and smooth. So they are perfect for "polishing" a game.
Title: Re: what good are the plus features?
Post by: steve on 18:41, 13 June 13
No. Not at all. I was answering regarding complex games (and 128 KB RAM is really not enought, I have serious trouble with that with some of my games...).
The Plus features can make things more beautiful, sound and smooth. So they are perfect for "polishing" a game.

I wonder if the CPC+ is fast enough to run 2-4MB of code, if most of the ram is filled with data you could load it from disk when needed.
Title: Re: what good are the plus features?
Post by: fano on 19:06, 13 June 13
I wonder if the CPC+ is fast enough to run 2-4MB of code, if most of the ram is filled with data you could load it from disk when needed.
Nope, the interest to have a lot of ram is not only for data, you can use precompiled stuff to speed up your code.I'd say most interesting features are (obviously) RGB palette, harware scrolling and sprites.Programmable interrupts are very interesting but vectorisation of theses is useless as it is bugged.DMA list are usefull too but limited to main 64K RAM =(
Title: Re: what good are the plus features?
Post by: steve on 19:38, 13 June 13
Nope, the interest to have a lot of ram is not only for data, you can use precompiled stuff to speed up your code.I'd say most interesting features are (obviously) RGB palette, harware scrolling and sprites.Programmable interrupts are very interesting but vectorisation of theses is useless as it is bugged.DMA list are usefull too but limited to main 64K RAM =(

Yes, that was my question, is the CPC fast enough to plough through 2-4 MB of code?
If we say the Z80 in the CPC+ can execute 500,000 instructions per second it would take 8 seconds to run through a 4MB program, what kind of program would that be?
Title: Re: what good are the plus features?
Post by: arnoldemu on 19:50, 13 June 13
Nope, the interest to have a lot of ram is not only for data, you can use precompiled stuff to speed up your code.I'd say most interesting features are (obviously) RGB palette, harware scrolling and sprites.Programmable interrupts are very interesting but vectorisation of theses is useless as it is bugged.DMA list are usefull too but limited to main 64K RAM =(
there is lots of discussion... who will be the first to make a game that pushes the plus like Pang or Robocop 2 or Navy Seals????
Then they can say how much better or not the plus is...

So far I have used the extra palette and sprites in a couple of games (one of which is in development) and in my 16kb game you can use the plus analogue sticks for full analogue control ;)

I haven't used the dma/interrupts yet fully yet.
Title: Re: what good are the plus features?
Post by: fano on 20:20, 13 June 13
Yes, that was my question, is the CPC fast enough to plough through 2-4 MB of code?
If we say the Z80 in the CPC+ can execute 500,000 instructions per second it would take 8 seconds to run through a 4MB program, what kind of program would that be?
Was not thinking to a full linear program but for example you can precompile tiles (R-Type used this for some) or sprites (Axelay could confirm but afaik he used this in his games)


there is lots of discussion... who will be the first to make a game that pushes the plus like Pang or Robocop 2 or Navy Seals? ???
Yep , Plus have been underused from now.Sadly, i must admit we need prefer to get the largest audience possible (on original machines) so making games for CPC is more interesting than making only for Plus.
Btw , good idea to try analog controller, i never used this type of device , that could be interesting.
About doing great things with Plus, i'd say it requires serious coding tasks as it is not easy to compensate its flaws.
Title: Re: what good are the plus features?
Post by: Bryce on 10:50, 14 June 13
512K of RAM has been available for the CPC since the 80's. Nobody ever wrote a game that used it though.

Bryce.
Title: Re: what good are the plus features?
Post by: fano on 11:28, 14 June 13
Sure, the problem for me is not the reality of a such extension but its popularity.It is a bit like 64K extension on 6128, it has been used because there are enough to be an interesting target for people who devellops games.
Title: Re: what good are the plus features?
Post by: TFM on 00:41, 15 June 13
512K of RAM has been available for the CPC since the 80's. Nobody ever wrote a game that used it though.

Bryce.
Nope, a lot of games / apps use more than 128 KB RAM.
 
Title: Re: what good are the plus features?
Post by: Bryce on 14:02, 15 June 13
Really? Which ones? I don't remember any game or app that required or made use of additional (above 128K) RAM.

Bryce.
Title: Re: what good are the plus features?
Post by: Gryzor on 19:10, 15 June 13
Me neither, this should be interesting to know.
Title: Re: what good are the plus features?
Post by: TFM on 19:18, 15 June 13
You can find it in the Wiki:
For 4 MB stuff take a look here:
Category:4 MB RAM Software - CPCWiki (http://www.cpcwiki.eu/index.php/Category:4_MB_RAM_Software)
 
For more than 128 KB stuff (actually your question), check out this:
Category:Extended RAM Software - CPCWiki (http://www.cpcwiki.eu/index.php/Category:Extended_RAM_Software)
(Most of them are able to use up to 512 KB RAM or even more).
 
Title: Re: what good are the plus features?
Post by: Gryzor on 20:43, 15 June 13
The 4MB category is all your stuff :D


The "Extended RAM" category also includes lots of your stuff and newer releases, leaving very few to wonder about - how did North and South use more than 128KB, for instance?
Title: Re: what good are the plus features?
Post by: TFM on 21:10, 15 June 13
Well, if you want I can create a 128KB+ category, which f.e. contains RDOS, Discology and so on... but maybe that would be too much.
Title: Re: what good are the plus features?
Post by: AMSDOS on 03:40, 16 June 13
Would APB fall into this Extended RAM Category? I know with the Disc (and maybe the Tape) version of the game if you only have 64k, the game does a lot more loading compared to if you've got 128k, though I don't know if the game needs any more than that. It's nice to see that the game makes use of the extra 64k if you've got it.  :)
Title: Re: what good are the plus features?
Post by: Devilmarkus on 12:54, 16 June 13
The wiki page with the extended ram apps only shows games what use 128k.

I never saw Orion Prime using 512k or so... It always uses 128k AFAIK.

You can add "Robocop" there, too. It provides speech samples when run on 128k machines.
Title: Re: what good are the plus features?
Post by: TFM on 00:54, 18 June 13
You also can do it  ;)
Title: Re: what good are the plus features?
Post by: pacomix on 00:57, 18 June 13
Any games that makes a difference between the non plus and the plus versions? For what I have seen so far... most of them are the same even Pang compared to Zapt'n'Balls and Prehistorik. But it is quite understandable. How would be the games market actually if there are two different versions of the PS3? One with 128MB of ram and another with 512? Not many I guess... Only storage room...
Title: Re: what good are the plus features?
Post by: ukmarkh on 01:03, 18 June 13
I hope one day, we all get to see the true power of the Plus model.
Title: Re: what good are the plus features?
Post by: TotO on 09:57, 18 June 13
Well, if you want I can create a 128KB+ category, which f.e. contains RDOS, Discology and so on... but maybe that would be too much.
I know that Discology can use DK'Tronics up to 256K and Vortex up to 512K.
Title: Re: what good are the plus features?
Post by: arnoldemu on 11:18, 18 June 13
I hope one day, we all get to see the true power of the Plus model.
I have 2 games where development has been paused, both will be finished and both use plus features.

I will e-mail some people for help when I am ready to finish them.
Title: Re: what good are the plus features?
Post by: TFM on 22:14, 18 June 13
I know that Discology can use DK'Tronics up to 256K and Vortex up to 512K.
Vortex is imcompatibel to all standard RAM expansions. Discology uses around 300 KB of RAM, because it doesn't not need more for a 3" disc. You can check that on any emulator. On real hardware it definitely works with the Dobbertin and the Inicron RAM expansions (also with the SF2).
Title: Re: what good are the plus features?
Post by: TotO on 22:22, 18 June 13
Vortex is imcompatibel to all standard RAM expansions. Discology uses around 300 KB of RAM, because it doesn't not need more for a 3" disc. You can check that on any emulator. On real hardware it definitely works with the Dobbertin and the Inicron RAM expansions (also with the SF2).
The Discology technical note "said" to support the full memory of the DK'Tronics (64 to 256K), Vortex (64 to 512K) and Silicon Disc (256K) on 464 and 664.
It "said" too that Discology allow to use 3"1/2 and 5"1/4 40/80 tracks simple and double side discs.
So, I think that 512K is not useless here... (sure, I have tested nothing)

http://www.cpcwiki.eu/imgs/1/13/Discology_Notice_Technique_Version_5.pdf (http://www.cpcwiki.eu/imgs/1/13/Discology_Notice_Technique_Version_5.pdf)
Title: Re: what good are the plus features?
Post by: mr_lou on 07:06, 19 June 13
Any games that makes a difference between the non plus and the plus versions? For what I have seen so far... most of them are the same even Pang compared to Zapt'n'Balls and Prehistorik. But it is quite understandable. How would be the games market actually if there are two different versions of the PS3? One with 128MB of ram and another with 512? Not many I guess... Only storage room...

There is no difference between the CPC and CPC+ in regards of memory.

I'm no expert, but as far as I've understood, the differences are:
So the biggest "pain" for developers (I guess) is to change their code to use hardware sprites instead of software rendering, while the biggest "pain" for graphics artists would be to re-do all of their graphics. I can certainly understand why they don't feel like doing that, especially considering that the CPC version of the game runs just fine on the CPC+ too. The only one who has it easy is the musician, who doesn't have to create another version of his tracks.

I'd love to see more CPC+ games though.
Title: Re: what good are the plus features?
Post by: TFM on 20:51, 21 June 13
Thank's for the information  :)
Title: Re: what good are the plus features?
Post by: mr_lou on 21:31, 21 June 13
Thank's for the information  :)

I wrote that to pacomix, who expressed a lack of knowledge.

No need to be a jerk just because you know all there is to know yourself. ;-)
Title: Re: what good are the plus features?
Post by: TFM on 21:34, 21 June 13
I wrote that to pacomix, who expressed a lack of knowledge.

No need to be a jerk just because you know all there is to know yourself. ;-)
And I posted to another topic! Don't know why it appeared here! You better take that Jerk back, or I make a smiting game about you  :laugh:
Title: Re: what good are the plus features?
Post by: mr_lou on 21:35, 21 June 13
Your PC is obviously drunk then.

Don't run Windows.
Title: Re: what good are the plus features?
Post by: TFM on 21:36, 21 June 13
It's IE !!! That's even worse - @work btw.... However you explanation was well.
 
But my comment was going to TotO in a complete other section of the forum...
Title: Re: what good are the plus features?
Post by: Executioner on 05:24, 18 October 13
So can anyone imagine a game using all the plus features that could not run on the CPC or at the same speed?

Actually, Frogger on the Plus uses most of the Plus features: hardware sprites, hardware soft-scroll, palette, DMA sound and raster interrupts.
Title: Re: what good are the plus features?
Post by: TFM on 20:17, 18 October 13
Oh really? You use DMA sound? Isnt't that a big waste using a lot of RAM?

Title: Re: what good are the plus features?
Post by: redbox on 22:55, 18 October 13
Oh really? You use DMA sound? Isnt't that a big waste using a lot of RAM?

Not it you know how to do it properly.

Foes - data in first 64kb of RAM and instructions are Words.
Friends - iteration compatible playlists.
Title: Re: what good are the plus features?
Post by: andycadley on 23:13, 18 October 13
Anyone in any doubt of whether the Plus can beat the ordinary CPC should just run Robocop 2. It's a very flawed game in many, many ways but it is one of the better demos of what the Plus could do. There is nothing on the ordinary CPCs which even comes close to being as smooth or as pretty.
Title: Re: what good are the plus features?
Post by: AMSDOS on 23:26, 18 October 13
Anyone in any doubt of whether the Plus can beat the ordinary CPC should just run Robocop 2. It's a very flawed game in many, many ways but it is one of the better demos of what the Plus could do. There is nothing on the ordinary CPCs which even comes close to being as smooth or as pretty.

That maybe true, though from a programming perspective I have no way of testing a routine on a real Plus because Amstrad refused to ship any to Australia - and emulators just don't cut the dice. :(
Title: Re: what good are the plus features?
Post by: Bryce on 23:33, 18 October 13
They are more difficult to find in Australia, but there are many European sellers that are willing to ship there. But they're not particularly cheap here either :D

Here's one that was on offer recently: http://www.amibay.com/showthread.php?t=51014 (http://www.amibay.com/showthread.php?t=51014)
Gone already, but they do pop up quite regularly.

In fact, contact Kris (he's sold three in the last few weeks) and he could probably organise one for you. He's a member here too as far as I know.

Bryce.
Title: Re: what good are the plus features?
Post by: TFM on 23:51, 18 October 13
Anyone in any doubt of whether the Plus can beat the ordinary CPC should just run Robocop 2. It's a very flawed game in many, many ways but it is one of the better demos of what the Plus could do. There is nothing on the ordinary CPCs which even comes close to being as smooth or as pretty.


Time for you to take a look at my Giana Sisters WIP.  ;) 


However I agree that the Plus is superior to the CPC old generation, because it just got some more features, but doesn't lack the old ones. [nb]Except some fancy CRTC modes, which never got used in games anyway.[/nb]
Title: Re: what good are the plus features?
Post by: AMSDOS on 23:54, 18 October 13
They are more difficult to find in Australia, but there are many European sellers that are willing to ship there. But they're not particularly cheap here either :D

Here's one that was on offer recently: http://www.amibay.com/showthread.php?t=51014 (http://www.amibay.com/showthread.php?t=51014)
Gone already, but they do pop up quite regularly.

In fact, contact Kris (he's sold three in the last few weeks) and he could probably organise one for you. He's a member here too as far as I know.

Bryce.

I found a Plus Monitor on eBay, though the price seemed to be a bit high at around $80 US, though at the moment the Aust Currency is almost on Par for the Greenback. I would be interested in a working machine which would reflect on the price.
Title: Re: what good are the plus features?
Post by: Bryce on 00:06, 19 October 13
A CM14 for $80?? That is high, you'll get one for a quarter of that usually.

A recent sale (from Kris too): http://www.amibay.com/showthread.php?t=51408&highlight=cm14 (http://www.amibay.com/showthread.php?t=51408&highlight=cm14)
Unfortunately the postage will probably be a killer from the US too.

Bryce.
Title: Re: what good are the plus features?
Post by: Executioner on 02:59, 19 October 13
Oh really? You use DMA sound? Isnt't that a big waste using a lot of RAM?

Not really.. The way it works is to prepare a DMA buffer for a single frame at a time. All it has to do is write all the register changes for the frame into a buffer rather than doing all that nasty IN/OUT stuff with the PPI.
Title: Re: what good are the plus features?
Post by: AMSDOS on 04:55, 19 October 13
A CM14 for $80?? That is high, you'll get one for a quarter of that usually.

A recent sale (from Kris too): http://www.amibay.com/showthread.php?t=51408&highlight=cm14 (http://www.amibay.com/showthread.php?t=51408&highlight=cm14)
Unfortunately the postage will probably be a killer from the US too.

Bryce.

Probably, the only other dilemma I'd have if I got a Plus Machine, would be how much I would be using it, I'd be told to get rid of my 6128 which is also a nice machine.  :D
Title: Re: what good are the plus features?
Post by: TFM on 21:50, 19 October 13
Not really.. The way it works is to prepare a DMA buffer for a single frame at a time. All it has to do is write all the register changes for the frame into a buffer rather than doing all that nasty IN/OUT stuff with the PPI.


Ah understood. Instead of feeding the PSG, you feed the DMA. Well, I though you may have the whole song / sounds in big copper program. But just feeding the DMA in time is a great idea. Saves time and space.
Title: Re: what good are the plus features?
Post by: TFM on 21:52, 19 October 13
Probably, the only other dilemma I'd have if I got a Plus Machine, would be how much I would be using it, I'd be told to get rid of my 6128 which is also a nice machine.  :D


A no! A Plus and the classic 6128 is the perfect combination  :) :) :)
Title: Re: what good are the plus features?
Post by: Bryce on 21:55, 19 October 13
My two most used machines are my 6128 and 6128+, I like to swap every few days. Although now that I have a 664, the 6128 is starting to be used less.

Bryce.
Title: Re: what good are the plus features?
Post by: beaker on 00:26, 20 October 13
I tend to use my original 6128 more than my 6128 plus... One day I'll get a 664!!!  :laugh:

Actually, that's a lie, I actually use my BBC Master and Atari ST with HxC more than my Amstrads of late...  :-[ and when the power was off while the electrician was around last week I was playing on the Gamegear...  ;D but before, I used my original 6128 more. It's nice having both though...
Title: Re: what good are the plus features?
Post by: Gryzor on 17:47, 20 October 13
When the electrician was over I was playing Lawnmower Sim on my NC :D