CPC Vs GX4000 - Comparison of the ported games.

[Novabug]

Right, this has taken a while but it's finally ready. A Side-by-Side look at both versions of the same game, the ones that were so-called dumps of CPC games.


This was something I wanted to do for a while as I felt it had not been extensively covered before. So I discover the actual differences between the versions and demonstrate them. Some games are, as expected, exactly the same, but many were not. This has been a labour of love for me so I would appreciate as much sharing and feedback as possible. The series is split into 5 parts for easy viewing, this is the first episode. I will be posting further parts in due course. I hope you all enjoy.


CPC Vs GX4000 Part 1 -

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Mucho Love. Novabug

[MacDeath]

nice video.

Batman actually has the palette slightly redone : the medium Red from CPC is turned into some orange.. the PLUS palette actually has some somewhat redundant colours and really they only started the job but did nothing.

The tile set (the bricks) would also have one octet at one point to mark the start of the tileset... this makes those 2 pixels in Orange... WTF ?



Really, we may try to patch this...


Barbarian 2 : some tiles would display some details that the badly set palette (redundant inks/colours) that would hide them.




concerning the list :

>> Panza kick Boxing : despite being a "port", the GX4000 version really has a lot of differences.

>> I think Switchblade came first on GX4000 then was ported to Spectrum and CPC... should be verified.

>> Tennis cup is also a CPC port the same way as Pinball Magic : Mode1 games turned into Mode0 games with hardware sprites added... but really those two can be considered quite different versions from the CPC... port on some parts but it is like compair a CGA PC version and an Atari ST version (sort of) or perhaps even an ST with an Amiga.
basically those

[andycadley]

I suspect the lack of title screens was a way of cramming the game into the cheapest cart possible, as every extra bit of ROM in them cost significant money. So a big 16K bitmap that was really only in the tape versions so that it looked like it was doing something during the long load was probably seen as easily expendable if it cut costs. The wipe effect on Batman is more of an oddity, but I wonder if it somehow just got dropped accidentally when the "load new level" routine was switched to read form cart rather than tape/disk/extra RAM.

It's a real shame the GX got so many of these poor effort conversions though, even the changes that were made really didn't feel like much more than a half hearted effort.

[MacDeath]

The cartridges were limited to 128K ROM.
Amstrad told bigger ROMs were possible but they never purchased any, nor let the Game producers provide somes...


Had Amstrad got a stockpiles 256K ROMs instead of 128ks, really could have been quite a different Jazz...

On the other hands, sometimes the devs would even waste space when 128k was actually too much... tape games would rarely fill 128k actually.
Titus was guilty, those huge overscan intro pages were cheap trick to mask the tape-64k game inside the cartridge.

Also not sure games would often use compression or procedural things, despite the 64k RAM was quite usefull for a "console" setting with ROM and would actually allow this, but hey, just put the CPC code and that's it..

fire and forget is perhaps the only decent titus game in the bunch.

NoExit was full of bugs... missed opportunity actually.

Mystical is the only Infograme "somewhat decent effort, just because the CPC version was already cute.

Klax was also such a missed opportunity, but hey, CPC version was good to begin with.
no 256x256 sized screen though... also no sound samples as with Atari LYNX...


Loriciel did quite well beside the "unfinished" Copter 271... they managed to provide decent Atari ST level games on the console.

[Novabug]

nice video.

Batman actually has the palette slightly redone : the medium Red from CPC is turned into some orange.. the PLUS palette actually has some somewhat redundant colours and really they only started the job but did nothing.

The tile set (the bricks) would also have one octet at one point to mark the start of the tileset... this makes those 2 pixels in Orange... WTF ?



Really, we may try to patch this...


Barbarian 2 : some tiles would display some details that the badly set palette (redundant inks/colours) that would hide them.




concerning the list :

>> Panza kick Boxing : despite being a "port", the GX4000 version really has a lot of differences.

>> I think Switchblade came first on GX4000 then was ported to Spectrum and CPC... should be verified.

>> Tennis cup is also a CPC port the same way as Pinball Magic : Mode1 games turned into Mode0 games with hardware sprites added... but really those two can be considered quite different versions from the CPC... port on some parts but it is like compair a CGA PC version and an Atari ST version (sort of) or perhaps even an ST with an Amiga.
basically those

Hey, these games will all be covered in later episodes.

[Novabug]

The cartridges were limited to 128K ROM.
Amstrad told bigger ROMs were possible but they never purchased any, nor let the Game producers provide somes...


Had Amstrad got a stockpiles 256K ROMs instead of 128ks, really could have been quite a different Jazz...

On the other hands, sometimes the devs would even waste space when 128k was actually too much... tape games would rarely fill 128k actually.
Titus was guilty, those huge overscan intro pages were cheap trick to mask the tape-64k game inside the cartridge.

Also not sure games would often use compression or procedural things, despite the 64k RAM was quite usefull for a "console" setting with ROM and would actually allow this, but hey, just put the CPC code and that's it..

fire and forget is perhaps the only decent titus game in the bunch.

NoExit was full of bugs... missed opportunity actually.

Mystical is the only Infograme "somewhat decent effort, just because the CPC version was already cute.

Klax was also such a missed opportunity, but hey, CPC version was good to begin with.
no 256x256 sized screen though...


Loriciel did quite well beside the "unfinished" Copter 271... they managed to provide decent Atari ST level games on the console.

What quizzes me is why some things are missing and vice-versa. More games to come but on Batman for example, it has a nice new title screen but the scatter SFX is missing. Memory used for the graphic instead?

[MacDeath]

Hey, these games will all be covered in later episodes.

yea but you put some spoilers in the video..   

What quizzes me is why some things are missing and vice-versa. More games to come but on Batman for example, it has a nice new title screen but the scatter SFX is missing. Memory used for the graphic instead?

I have a theory : they aimed at a proper PLUS version but had no time to do it.
I mean they actually edited the Palette and there is a "mark" on the tileset... but I guess they had no time so they rushed it and went on better job at modding for later OCEAN prods.

barbarian2 was a palace software game (were they purchased ? license ?), so the Devs/codes were certainly not at OCEAN to really modify original code.

Operation Thunderbolt : they actually did the palette editing that was probably only started/abandonned on Batman.

I guess they had to release quite fast and had not enough coders and graphicians to get all those early games developped properly or edited properly.

Also they may have wanted to put some samples for batman but failed at getting the DMA sound channels to work or had no space/time.


only speculations of course.

Would be fun to ask at OCEAN's facebook page.

tried :
http://www.facebook.com/groups/4149619741/permalink/10154039891844742/

[Arnaud]

Nice video, waiting for part 2.

[ukmarkh]

I read somewhere, when playing single player, that if you only concentrate on your side of the screen in Operation Thunderbolt, on the GX4000, the game is much easier, as on the two player side of the screen, enemies don't harm you? 

[Novabug]

tea but you put some spoilers in the video.. 
I have a theory : they aimed at a proper PLUS version but had no time to do it.
I mean they actually edited the Palette and there is a "mark" on the tileset... but I guess they had no time so they rushed it and went on better job at modding for later OCEAN prods.

barbarian2 was a palace software game (were they purchased ? license ?), so the Devs/codes were certainly not at OCEAN to really modify original code.

Operation Thunderbolt : they actually did the palette editing that was probably only started/abandonned on Batman.

I guess they had to release quite fast and had not enough coders and graphicians to get all those early games developped properly or edited properly.

Also they may have wanted to put some samples for batman but failed at getting the DMA sound channels to work or had no space/time.


only speculations of course.

Would be fun to ask at OCEAN's facebook page.

tried :
https://www.facebook.com/groups/4149619741/permalink/10154039891844742/

Good theory yeah. I'm guessing it's the time constraints, which would raise more questions. Or, it could just be basic laziness. The scatter SFX is still a weird one though. I talk about Klax in the next ep, and ponder why the GX pulls off the 6128 version rather than the 464, but oops, spoilers.

[Novabug]

I read somewhere, when playing single player, that if you only concentrate on your side of the screen in Operation Thunderbolt, on the GX4000, the game is much easier, as on the two player side of the screen, enemies don't harm you?

hmmm, From the years of playing it, I have never noticed. I'll have to test that theory.

[Sykobee (Briggsy)]

Is that only 9 colours (10 if you count the duplicate sky colour) in Barbarian 2 ... sure the enemies add an orange and a vivid green too, but it's barely there.

This is crying out for a new .cpr with updated background graphics! And maybe a raster sky gradient.


OpThunderbolt could have at least had a smooth road scroll using the programmable raster (and maybe not white,black,grey). Still, better than the CPC, and the menu screen is way better (some sprites at least, for the logos). The premise is broken, full screen scaling effects (aka software rendering jerkily) at such a pace were not the CPC's forte. OTOH why are you running forward at such a pace in the first place...



Batman could have had some bonus tiles defined for each level surely.


Looking forward to part 2.

[MacDeath]

Longplays of co-op games are far too often done playing alone...

Is that only 9 colours (10 if you count the duplicate sky colour) in Barbarian 2 ...
This is crying out for a new .cpr with updated background graphics! And maybe a raster sky gradient.

I guess it is not the place to talk about that but the game actually places a raster/palette change between the title zone and the Play zone.

This enable to use simple palette swaps to change the colours of the life gems... really.

But also many inks are actually using same colours.
It can also be so you swap colours for monsters with jsut the change of some inks...still it was done with feet instead of hands. 

The tiles are actually like the C64 version, the sky is supposed to have 2 layers of colours... the faces on piques are also supposed to have sides with different inks.

you may check this old topic and feel free to resurect it :
Barbarian 2 oddities...

[Sykobee (Briggsy)]

Yeah, I wasn't counting the standard scoreboard/playzone interrupts.


The Amiga and ST versions are just as bad in the background graphics though, IMO. Like someone just found the archaic spraycan tool in PC Paintbrush.


If the graphics are encoded then maybe it's not worth it. In the end it's just a big-character-fighting-game but with various enemies and a 'map' to walk through.

[MacDeath]

Well, Barbarian suffer some lackluster control and maneuverability.
also to have the screen speccy sized doesn't help as the holes in the middle would have too few spaces on sides and so on.

Still with better graphics, it can be a game to play. The exploration part and the patterns for each monsters can be quite a challenge.

Thargan was quite superior anyway.

[||C|-|E||]

Very cool video! I enjoyed it a lot and it is very illustrative as well! 

[Phantomz]

@Novabug

If you've got a C4CPC you can now have a version of "Barbarian 2" with the loading screen. 

It's on the Converted GX4000 .cpr - The topic  thread now. 

[ukmarkh]

OpThunderbolt could have at least had a smooth road scroll using the programmable raster (and maybe not white,black,grey).

The only negative I can find with Operation Thunderbolt is the lack of a proper cross-air, if the game had one like seen in Operation Wolf, I would have loved it, regardless of the scroll. Without a proper cross-air, the game is a mess! I have no idea what the programmers were thinking, somebody should have noticed.


If you play the Amiga version, the scroll going forward is better, but still not convincing, a bit choppy as well. Only version I've played where it looks convincing is the arcade version. 

[MacDeath]

It was a way to match the arcade...

Arcade uses some guns on base... like analog joysticks, not quite sire they were "light guns", but the fixed gun's basis was somewhat properly set so it was accurate with no flashing.

Basically such system may be done on a PLUS via the analog port... I guess, but you would have to measure properly where you put the gun compared to screen.


So yeah, arcade uses no crosshair, you just have some laser targeting as bonus option sometimes.

Wich is unfit for joypad/stick playing computers off course.

As you had to fire to see where you are, you waste ammunitions = harder.

lightguns are another issue : can't put proper crosshair... and really can't properly fire in full auto rate unless you get some epilectic inducing 25hz white screen flashing...
Not even sure you can use 2 lightguns at the same time (actually this may be possible perhaps).



So yeah, games like Opwolf/Thunderbolt/spacegun /railFPS  are some sort of things that should get modern production.

well, CyberChiken/Huhn was actually one of those.


Still GX4000/PLUS could really have great things like that.

= hard sprite crosshairs / layer.
= perhaps handle some analog port things so some crazyax dudes may create some hardware to play more like the arcade cabinets with fixed guns... or use analog joysticks or some analog mouse or whatever...
= scrolls, palette, whatever PLUS can.
= lightgun too... or even lightpens...



SpaceGun was an unfinished mess of a hidden speccy port of suck...

[andycadley]

Doesn't the CPC+ have proper hardware support for the lightgun, allowing it to work by detecting the position of the raster beam? I thought it did, but I've never seen a real Plus lightgun, so not paid much attention to coding for one.

[Novabug]

@Novabug

If you've got a C4CPC you can now have a version of "Barbarian 2" with the loading screen. 

It's on the Converted GX4000 .cpr - The topic  thread now. 

Excellent. I'm going from the original carts here though.

[Novabug]

It was a way to match the arcade...

Arcade uses some guns on base... like analog joysticks, not quite sire they were "light guns", but the fixed gun's basis was somewhat properly set so it was accurate with no flashing.

Basically such system may be done on a PLUS via the analog port... I guess, but you would have to measure properly where you put the gun compared to screen.


So yeah, arcade uses no crosshair, you just have some laser targeting as bonus option sometimes.

Wich is unfit for joypad/stick playing computers off course.

As you had to fire to see where you are, you waste ammunitions = harder.

lightguns are another issue : can't put proper crosshair... and really can't properly fire in full auto rate unless you get some epilectic inducing 25hz white screen flashing...
Not even sure you can use 2 lightguns at the same time (actually this may be possible perhaps).



So yeah, games like Opwolf/Thunderbolt/spacegun /railFPS  are some sort of things that should get modern production.

well, CyberChiken/Huhn was actually one of those.


Still GX4000/PLUS could really have great things like that.

= hard sprite crosshairs / layer.
= perhaps handle some analog port things so some crazyax dudes may create some hardware to play more like the arcade cabinets with fixed guns... or use analog joysticks or some analog mouse or whatever...
= scrolls, palette, whatever PLUS can.
= lightgun too... or even lightpens...



SpaceGun was an unfinished mess of a hidden speccy port of suck...

Spacegun never made it to cart, or did it? I saw a copy of it for sale a while back, was tempted but remembered it a spec port.


For me, it's the scaling/scrolling that screws OP thunderbolt. I can live with the crosshair thing, because you can get a 'sight' once you have shot the right object.

[MacDeath]

Space Gun was a PLUS game on 6128PLUS only, cartridge was most probably a bootleg or a Fake.


Also you know, you don't have to copy the whole post (mine are so long... lol) as quotes...  just parts of them.


yeah, Op Thunderbolt "vertical" scrolling (how is it actually called ?) lack proper smoothneed... would have needed more rasters effects... they must still use the CPC ones, CPC couldn't perform rasters that smooth and it was a cheap trick to use the "synched raster lines".

Also some parts of background are too adapted to CPC palette.
Some parts use massive ditherings because there is only one grey on CPC.
Those could use proper different greys on PLUS but yeah, had to redo a few tiles.



Dithered grey... for the walls.

Dithered grey too :   


Also the greens are a bit too similar, lacks some contrast. Skin colour are perfect though...

now should take this :

then add a few rasters... and some hardsprites patches for extra colours : 16bit perfect.
But yeah really some coders should do something...

[ukmarkh]

I just played OP Thunderbolt on Mame with mouse, there's an option to turn on the Cross-air, and I can't live without it.

[Novabug]

Space Gun was a PLUS game on 6128PLUS only, cartridge was most probably a bootleg or a Fake.


Also you know, you don't have to copy the whole post (mine are so long... lol) as quotes...  just parts of them.

Yeah, I know. see? haha, I just forget to remove the rest of the post.