Enterprise Forever

:UK => Programming => Topic started by: geco on 2020.February.14. 08:53:18

Title: Converting old Ocean games
Post by: geco on 2020.February.14. 08:53:18
Both games are looking good, Why did you stopped to develop games for z80 computers?
If i may ask the sources, i would convert them to EP, the graphics can be stolen from the released game :)
Title: Re:Converting old Ocean games
Post by: gflorez on 2020.February.14. 12:04:22
Great! we will see two (almost) original game releases on the horizon this year...

If they where programmed on an Ep.... we can say they are originals, can't we?
Title: Re:Converting old Ocean games
Post by: elmer on 2020.February.16. 21:43:11
Both games are looking good, Why did you stopped to develop games for z80 computers?

Thank you! :)

While both games received good reviews at the time, it is definitely Renegade and my 3rd Amstrad title, Gryzor (https://www.youtube.com/watch?v=M-Sng7RrdRg&feature=youtu.be&t=365), that players still seem to have fond memories for all these decades later on.

I stopped developing for the Amstrad because the ST and Amiga were becoming popular (and cheap) enough that my company wanted me to switch over to those ... and I was quite happy to get to develop for the more-powerful machines.


If i may ask the sources, i would convert them to EP, the graphics can be stolen from the released game :)

Yes, extracting the graphics from the existing game would be the way to go. I did that myself recently for one of my old Amiga/ST games.

However, I really can't see giving out old source just to have a game ported over as-is to the Enterprise without any significant changes.

If someone actually cared enough about the game, and about the Enterprise computer to go ahead and make some changes to improve it, either in terms of the game itself, or to take advantage of the Enterprise's unique capabilities, then that is more interesting.


For Short Circuit, that would probably be changing the game itself so that it gave the player more hints about what they need to do (because the game is almost impossible for anyone but the original developers to actually beat). The scrolling printout on the screen should probably be made faster, and the message that you can only carry 3 items needs to be a *lot* faster, because it is totally frustrating the way that it is.

Those changes, and whatever-else the developer who was porting it wanted to add, would provide an improved game on the Enterprise, and so be worth doing.


For Renegade, the obvious thing to add is the horizontal scrolling that had to be dropped on the Amstrad because the machine couldn't do it in hardware, and it was too slow to do it in software. With an Enterprise 128 you have twice the memory of the Amstrad 464 that the game was targeted for, and plenty of memory available to do double-buffered hardware scrolling.

Again, this would make an important visual improvement to the Enterprise version, and so make it worth doing, and also show the power of the Enterprise's hardware.


For Gryzor ... that it the one that I'd be the most intrigued to see on the Enterprise, because it would be possible to both add scrolling to the game, and probably also to add the extra stages from the NES version of the game. However, that is a project that I would want to do myself. I don't have an Enterprise anymore for testing, but I'd develop the game in ep128emu anyway, just to retain sane assembly times.


Anyway ... I'm new here, and you don't know me, but similarly I also don't know you, and I don't know about your programming capabilities and interests.

May I ask what games and/or other Enterprise programming you have done?
Title: Re:Converting old Ocean games
Post by: Zozosoft on 2020.February.16. 22:19:51
May I ask what games and/or other Enterprise programming you have done?
I recommend look arround here (https://enterpriseforever.com/summaries-from-the-hungarian-topics/latest-developments-for-enterprise/) for a Geco's programs :-)

And some example youtube links:
Bricky Prise (https://www.youtube.com/watch?v=-q8d8XWXnyA) original game
Panic Man (https://www.youtube.com/watch?v=ZcPdqRzZkJ8) original game
International Karate Plus (IK+) Reloaded (https://www.youtube.com/watch?v=KvTHOaR0E9w) conversion
Chase H.Q. (https://www.youtube.com/watch?v=WXCk-lGaKbM) conversion
Operation Alexandra (https://www.youtube.com/watch?v=V8TfVLIrxDo) conversion
Adiós A La Casta: Episode 1 (https://www.youtube.com/watch?v=Ozpdf_p5zgg) conversion
Adiós A La Casta: Episode 2 (https://www.youtube.com/watch?v=atNI0AMza8k) conversion
Treasure Cave (https://www.youtube.com/watch?v=wmmxRWdMrhw) original game
El Tesoro Perdido de Cuauhtémoc (https://www.youtube.com/watch?v=3KOkTQU0qhY) conversion
R-Type (2018 CPC remake) (https://www.youtube.com/watch?v=m1VjO7mUV_s) conversion
Nigel Mansell's Grand Prix (https://www.youtube.com/watch?v=6GIzqTJhQPE) conversion
Inside Outing (https://www.youtube.com/watch?v=jwTae4lC-i0) conversion
Green Beret (https://www.youtube.com/watch?v=Aiy_9Mz--5M) conversion

SID Player (https://www.youtube.com/watch?v=6CKt9noxA7s)
SIDBasic (https://www.youtube.com/watch?v=8UxG_sjeuyM)
MOD Player (https://www.youtube.com/watch?v=eNet1CQtnCc)
Title: Re:Converting old Ocean games
Post by: gflorez on 2020.February.16. 23:30:14
I would add that Geco's conversions have been consented by the authors, being he extremely careful to not change the gameplay, graphics or music, only adding some Enterprise exclusive characteristics like for example, scrolls, colourful horizons or more speed.

In this case it would be great a collaboration between you, Elmer, and Geco. You, as the author, know the lacks of the games and how to improve them, and Geco, has a great experience on game conversions and on the two computer architectures.

Please, give him an opportunity....
Title: Re:Converting old Ocean games
Post by: geco on 2020.February.17. 09:11:55
Hello Elmer

My capabilities are not so good as yours, but i always try to add some EP extra to my conversions,  and i would be happy to make EP versions from the 3 mentioned games, we could work together, i make the EP version based on your hints, and send you the result to check, if something should be changed or not.
I have 2 EP's but EP128emu is so good, that i use it for everythng.

Small correction SIDBasic is done by Istvánv and me, but mine part was much less in the final version, MOD Player is a conversion of MOD Player of Stefan Drissen on SAM coupé, changes: buffering part has been modified (became smaller, and bit faszer),the player plays digi in interrupt. and looking has been changed.
Title: Re:Converting old Ocean games
Post by: elmer on 2020.March.15. 04:00:56
Sorry for the long silence, it's been a really busy month for me.

My capabilities are not so good as yours, but i always try to add some EP extra to my conversions,  and i would be happy to make EP versions from the 3 mentioned games, we could work together, i make the EP version based on your hints, and send you the result to check, if something should be changed or not.

I've taken a look at the excellent work that you've done, and I'd be happy to work with you on this. :)

Honestly, I don't think that you'll really have much, if any, need of my input at all, you seem perfectly capable of doing a great job on the conversion by yourself.

Let's move the conversation to PM, and I'll send you some source code.

The only thing is that I'd like to do the Gryzor conversion myself (if I can find the source to it), since I have a particular fondness for that game.

I've ordered an Enterprise 64 from eBay to replace the old machine that I gave away many, many years ago, and hopefully I'll be able to use that to do some testing, if I can find a way to download code to it, and if there's a way to increase its memory to 128KB (or more).
Title: Re:Converting old Ocean games
Post by: geco on 2020.March.15. 08:37:54
Welcome back ☺
I think you can give good ideas to make those good programs even better to use ep capabilities. 😊 and if i can not solve any of ideas i would like to ask your help.
Sure , if you does not find the source of Gryzor, i can try to create it from the binary if you wish ☺
Until you do not have an sd card reader (it can be ordered from forum member Szörg, you can find his contact in the forum in sd card topic, or i can search it for you when i turn on my computer, and do not use phone) you can create tape files by epte or tapir and load them.
As i remember memory expansion can be ordered from Pear and Gotek.
Title: Re:Converting old Ocean games
Post by: gflorez on 2020.March.15. 10:13:05
Great news!

But a 64KB Enterprise is not the best model to start with. First it has EXOS 2.0, slightly incompatible with the definitive 2.1 version all stock 128KB models have. All modified EXOS Roms by Zozo are based on it.

Second, some hardware problems where fixed on the later 64KB models, but definitively on the 128KB model.
 
But almost all these issues can be fixed if you are handy and do not fear to open the EP.
Title: Re:Converting old Ocean games
Post by: Zozosoft on 2020.March.15. 19:53:12
Let's move the conversation to PM, and I'll send you some source code.
Great news! I believe you and Geco will make awesome Enterprise versions!
Title: Re:Converting old Ocean games
Post by: elmer on 2020.March.17. 02:19:52
Sure , if you does not find the source of Gryzor, i can try to create it from the binary if you wish ☺

I believe that an old colleague still has a copy of the final printout that I made, and he's going to send it to me.

If I can scan that listing in, then it would be tremendously helpful ... I really want to see all of the old comments in the source code.


Until you do not have an sd card reader (it can be ordered from forum member Szörg, you can find his contact in the forum in sd card topic, or i can search it for you when i turn on my computer, and do not use phone) you can create tape files by epte or tapir and load them.

Thanks, I'll contact him!


As i remember memory expansion can be ordered from Pear and Gotek.

Thanks again! I've found Pear on here, I'll see if he still has any.

If I can get a 512KB memory expansion board, then that would be an absolute dream-come-true.


But a 64KB Enterprise is not the best model to start with. First it has EXOS 2.0, slightly incompatible with the definitive 2.1 version all stock 128KB models have. All modified EXOS Roms by Zozo are based on it.

Second, some hardware problems where fixed on the later 64KB models, but definitively on the 128KB model.
 
But almost all these issues can be fixed if you are handy and do not fear to open the EP.

My soldering skills are very rusty, and my eyes aren't what they once were, but I can certainly *try* to perform any upgrades that are needed.

Honestly, I will do almost all of the work in EP128EMU, the real hardware is mostly needed for testing a few hardware-specific routines, especially if I write a new sound-driver for the conversion.

The price of an EP128 these days seems far too high for my comfort, so I jumped on one of the Egyptian EP64 imports that have recently turned up on eBay.

The serial number is 71370, so I'm hoping that any of the hardware problems were fixed in a machine that was manufactured that late.

The machine even has Arabic characters on the keyboard as well as the English characters, which made it an interesting variant to see for sale.

Anyway, I'm afraid that I won't even be able to see the output from the computer (and verify the EXOS version) until I make an RGB-to-BNC cable, because I don't have a PAL TV.
Title: Re:Converting old Ocean games
Post by: gflorez on 2020.March.18. 10:01:37
The machine even has Arabic characters on the keyboard as well as the English characters, which made it an interesting variant to see for sale.

Anyway, I'm afraid that I won't even be able to see the output from the computer (and verify the EXOS version) until I make an RGB-to-BNC cable, because I don't have a PAL TV.

Yes, the emulator is the best tool to develop, with all its options to debug, find strings, trace, disassembly, etc.

You can know more about the Egyptian Enterprise units here (https://enterpriseforever.com/hall-of-fame/qa-with-werner-lindner-technical-director-of-the-enterprise-computers-gmbh/msg45483/#msg45483).

If you name the maker and model of your monitor we can aid you to make the video cable. If it has BNC connectors it is a professional one, sometimes they need Sync on Green or other strange ways to input the Sync signal.
Title: Re:Converting old Ocean games
Post by: Zozosoft on 2020.March.18. 12:32:52
Honestly, I will do almost all of the work in EP128EMU, the real hardware is mostly needed for testing a few hardware-specific routines, especially if I write a new sound-driver for the conversion.
From a developer view: most important difference at EP64/EP128 not just the memory size. At EP64 all memory are video memory, where the CPU accesses are delayed by the Nick chip. The extra 64K in EP128 or any other memory expansion runs at full speed. Like the Amiga Chip RAM and Fast RAM :-)

Another problem the different system memory map at EXOS 2.0 and 2.1+ versions. But if you programming on the right way, allocate memory from EXOS, don't using direct system memory addresses, then the program will run on any Enterprise configuration.
This is also true for using extra memory segments, many-many old program using directly the F8-FB segments, which are the internal 64K expansion of EP128. These programs still not running on EP64 even you have a external memory expansion. But if you programming on the right way, then no problem about where the expansion addressed.
Unfortunatelly there in Hungary where the most of Enterprise sold, only the 128K version exist. Then the most of programmers don't care about the EP64, games won't run on EP64, even if it is only 48K Spectrum conversion :roll:
About at the last 15 years, when international Enterprise community started, making the new programs are maximal possible compatibility, and lot of old programs are also fixed. (Still possible if the programs need more than 64K, or a full speed RAM, but can run on EP64 with any expansion.)
When Geco write for their releases "program are EXOS compatible" this is means these.

From a "gamer" view, if you want to enjoy all existing Enterprise programs need a EXOS 2.1+ and 64K expansion at F8-FB segments. Practicaly this is a EP128 :-)

But for a developing EP64 are ok, and optionaly any memory expansion if needed more or faster RAM.

In a ep128emu the memory timings emulated correctly.

Ps: what do you think, move your thread to a separate thread? Just suggest one right name for it :-)
Title: Re:Converting old Ocean games
Post by: elmer on 2020.March.19. 06:39:41
Ps: what do you think, move your thread to a separate thread? Just suggest one right name for it :-)

Absolutely, while a few of my earlier messages might be considered to be a legitimate part of this topic, we've gone far, far off the original thread by now.

If a moderator can split off most of the recent messages into a new thread, perhaps into the "Progamming" section, then that would seem like a great idea!

How about "Converting old Ocean games"?
Title: Re:Converting old Ocean games
Post by: Zozosoft on 2020.March.19. 08:14:51
If a moderator can split off most of the recent messages into a new thread, perhaps into the "Progamming" section, then that would seem like a great idea!

How about "Converting old Ocean games"?
Done :ds_icon_cheesygrin:
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.05. 21:32:36
Congratulations to Geco for doing such an excellent job on the Short Circuit conversion! :ds_icon_cheesygrin:

Renegade is going to be a much more difficult job to convert because I apparently only have a part of the source code archived.

Having said which, it is easy (for me) to see the progression/improvements in the code over the three games, and they were definitely built one on top of the other.

For my own part, I have been exploring and disasssembling the Gryzor game in the emulator, and have already started re-writing some of the routines to be a bit more efficient on the Enterprise because of both the screen layout, and the availability of 128KB of memory. :-)



Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.05. 22:38:36
From a developer view: most important difference at EP64/EP128 not just the memory size. At EP64 all memory are video memory, where the CPU accesses are delayed by the Nick chip. The extra 64K in EP128 or any other memory expansion runs at full speed. Like the Amiga Chip RAM and Fast RAM :-)
...
Another problem the different system memory map at EXOS 2.0 and 2.1+ versions. But if you programming on the right way, allocate memory from EXOS, don't using direct system memory addresses, then the program will run on any Enterprise configuration.
...
But for a developing EP64 are ok, and optionaly any memory expansion if needed more or faster RAM.

It's not hard to write code so that it uses the EXOS interfaces, so that's not going to be a problem.

But I am going to have to add some extra RAM to my EP64 because I'm going to need the extra space of a 128KB machine to do some optimizations to the code, add scrolling, and perhaps fit in some extra graphics.

The added speed of the faster RAM will also help, and may even allow me to draw a bigger screen than on the Amstrad.


The price of an EP128 these days seems far too high for my comfort, so I jumped on one of the Egyptian EP64 imports that have recently turned up on eBay.

The serial number is 71370, so I'm hoping that any of the hardware problems were fixed in a machine that was manufactured that late.

Anyway, I'm afraid that I won't even be able to see the output from the computer (and verify the EXOS version) until I make an RGB-to-BNC cable, because I don't have a PAL TV.

The Enterprise has arrived, and is as asolutely beautiful as I remember!

I already have a modern 9V-DC center-negative PSU that I can use to power the system, so that side of things is OK.

But I still have to make an RGB cable before turning the computer on and finding out what EXOS version is inside.


If you name the maker and model of your monitor we can aid you to make the video cable. If it has BNC connectors it is a professional one, sometimes they need Sync on Green or other strange ways to input the Sync signal.

I have a Panasonic BT-H1390Y, which can either use sync-on-green, or a separate composite-sync signal.

I also have a LCD TV/Monitor that can accept 15KHz TV signals through the VGA connector.

I'm not sure what the next step is to make/buy a cable that will work.

I have found a company in Spain that sells an Enterprise RGB-to-SCART cable, does anyone have any experience with that cable?
Title: Re: Converting old Ocean games
Post by: gflorez on 2020.April.06. 03:28:23
The cable from Retrocables makes perfectly its function, although the EP plug will need some tailoring to enter completely on the EP strange socket. I have one of these and it works good for a LCD TV with Scart connector.

If your LCD TV/Monitor doesn't have a Scart connector....  

You need to make a cable yourself....

One good new is that your two monitors directly accept the Enterprise RGB signals(Scart needs some additional resistors). And other one is that  our computer delivers both composite sync and split syncs signals apart from the RGB colour signals.

The CRT will give you the more accurate "classic" feelings of scan-lines and colours, but less pixel-perfect than the LCD. 13'' screen seems too little for today standards, but on the contrary it is enough retro..... Amazing professional specs (https://www.manualslib.com/manual/304655/Panasonic-Bt-H1390y.html?page=8#manual) in that jewel.

The VGA cable on 15KHz can be seen apparently like a good solution, but it depends a lot on the maker to be or not compatible with all the screen modes that an Enterprise could deliver. Of course the Interlaced mode is discarded, and some very high line modes(like for example the presentation screen of the new Short Circuit game), will be shown cut.  

Other drawback of multi-sync monitors is that they tend to show false colours for Pal, the palette they use is not so wide as the original. But even so, maybe it suits to you.

Resolutions and colours were the main attractive of the EP computer on its days, but also its stereo capabilities and, if your monitors don't have integrated amplifier and speakers you will need to use a pair of space-wasting external ones.....

To finish, the aspect ratio of the monitor is also important, because the EP was build on the 4:3 past era, and you probably don't want to see forever a flattened image or these ugly black strips at the sides on a 16:9 monitor.

For the Enterprise I better would recommend you to buy a cheap 4:3 second-hand LCD Stereo TV with Scart if your LCD TV lacks the connector or stereo sound. 15'' is enough, but 4:3 LCD TVs were manufactured even on 17'' or 19''.

If you still prefer the CRT monitor or the VGA multi-sync, I can make you a cable.
Title: Re: Converting old Ocean games
Post by: geco on 2020.April.06. 08:17:00
Congratulations to Geco for doing such an excellent job on the Short Circuit conversion! :ds_icon_cheesygrin:
Thank you very much :)

For my own part, I have been exploring and disasssembling the Gryzor game in the emulator, and have already started re-writing some of the routines to be a bit more efficient on the Enterprise because of both the screen layout, and the availability of 128KB of memory. :-)
Cool, i am waiting the result :), Gryzor with scrolling, and probably with other new features :)
I use DZ80 (http://www.inkland.org.uk/dz80/) for disassembling, the emulator is also very good, just the output is not so friendly if source is planned make from it, probably there are much better tools which can give more help to create source from binary ex IDA ( personally i do not like it :D ).
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.12. 21:55:47
For the Enterprise I better would recommend you to buy a cheap 4:3 second-hand LCD Stereo TV with Scart if your LCD TV lacks the connector or stereo sound. 15'' is enough, but 4:3 LCD TVs were manufactured even on 17'' or 19''.

I live in the USA these days, and TVs here never had either SCART nor any other type of RGB connector here, so nothing is available second-hand ... and most wouldn't display 50Hz 625-line signals anyway.


The CRT will give you the more accurate "classic" feelings of scan-lines and colours, but less pixel-perfect than the LCD. 13'' screen seems too little for today standards, but on the contrary it is enough retro..... Amazing professional specs in that jewel.

Yes, I got very, very lucky finding that monitor locally many years ago.

I think that it is the best option that I have for using with the Enterprise, especially since seeing the true colours and aspect-ratio is important for doing any development work on the computer.


If you still prefer the CRT monitor or the VGA multi-sync, I can make you a cable.

Thank you for the offer, I really appreciate it!

Honestly, I'd much rather buy a cable from someone like you who obviously loves and cares about the Enterprise, and who is actively involved in this forum, rather than some company that I have never heard of in Spain.  I'll send you a PM.
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.12. 22:11:44
I have extracted the main maps from Gryzor. It is funny to think that this is probably the first time in over 30 years that they have been in an editable format!  :cool:

Here's the first level in the original Amstrad colours ...

(https://live.staticflickr.com/65535/49766552357_df462d5a9c_o.png)


I've been working on coming up with a set of Enterprise colours that will make the game look both nicer, and more like the original arcade game.

Here is my favorite set of colors so far. The palette is still ordered in the original Amstrad order, and has not been remapped for the Enterprise with its colours 8..15 coming from the FIXBIAS setting.

First is the original Amstrad screen, and then the Enterprise screen.

This currently uses 17 colours instead of 16, but I am hoping that a raster-split will be possible to make it work.

(https://live.staticflickr.com/65535/49766554107_679a035981_o.png)

(https://live.staticflickr.com/65535/49766556167_70cc096c02_o.png)


Title: Re: Converting old Ocean games
Post by: geco on 2020.April.12. 22:41:48
Looks cool, raster split should work if any of colours are not used on any part of the screen, hopefully fixbias will not cause any problem :)
I like the new colours :)
Title: Re: Converting old Ocean games
Post by: SlashNet on 2020.April.12. 23:24:26
In EP palette enemies looks more visible. It's better.
Title: Re: Converting old Ocean games
Post by: szipucsu on 2020.April.13. 10:54:55
I have extracted the main maps from Gryzor.
I can see so much water in these pictures. Now I know why they are called OCEAN games. :D
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.17. 00:41:07
I can see so much water in these pictures. Now I know why they are called OCEAN games. :D

Hahaha ... good joke! :lol: 

But in this case, I think that you have to blame Konami for putting all of that water in the original arcade game ...

(https://vgmaps.com/Atlas/Arcade/Contra-Stage1-Jungle.png)


In EP palette enemies looks more visible. It's better.

Thanks, that is definitely one of the important goals in picking the Enterprise colours to use. :cool:


Looks cool, raster split should work if any of colours are not used on any part of the screen, hopefully fixbias will not cause any problem :)
I like the new colours :)

I'm still investigating to see whether a raster split will be useful in adding another colour or two.

The re-coloured Enterprise screen grab that I posted earlier is using a FIXBIAS-compliant set of colours, but I'm only finding a way to use at-most 6 out of the 8 colours for any of the FIXBIAS values that I've tried.

If I can't find an easy raster split, then I'll have to change some of the sprites so that they use one or both of the unused colours in the FIXBIAS set.

In order to see what that might look like, I've extracted the rest of Mark's graphics from the Amstrad game.

For anyone interested in seeing the whole set, so that you can get a visual idea of how things were put together decades ago, I'm attaching a zip file.
Title: Re: Converting old Ocean games
Post by: geco on 2020.April.17. 08:57:03
I have mostly problem with the pink, or light purple :D , and with the orange if i use bias 1fh , in this case i use color 249 as orange :D , and pink/light purple for faces, the sprites look as bit drunken guys :D
By the original picture the water and sky border could be an ideal split, but on the CPC screen as i see the blues are used at the top too.
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.20. 05:35:40
hopefully fixbias will not cause any problem :)

I have mostly problem with the pink, or light purple :D , and with the orange if i use bias 1fh , in this case i use color 249 as orange :D , and pink/light purple for faces, the sprites look as bit drunken guys :D

Hmmm, yes FIXBIAS can be quite challenging to work with! :shock:

I guess that a FIXBIAS of either 00h or 1Fh are the obvious values to use when converting Amstrad games, but I *really* don't like either of those settings. The pink and purple colours seem like they are practically unusable.


I have spent the last few days working on the Gryzor loading screen, trying to get more comfortable with the different FIXBIAS values, and also editing the screen so that there are only 8-or-less unique non-FIXBIAS colours on each line of the screen.

Once I had results that seemed to look OK, then I figured out where to put some raster splits to add a few extra colours to the screen.

Here's the result (with 24 colours displayed), together with the Amstrad original for comparison.

Please note ... I'm not an artist, so this is about the best that I can do! ;-)

(https://live.staticflickr.com/65535/49799159307_c903966508_o.png)
Title: Re: Converting old Ocean games
Post by: Dr.OG on 2020.April.20. 05:48:50
Looks really nice, better than the original!
Title: Re: Converting old Ocean games
Post by: geco on 2020.April.20. 08:15:19
I guess that a FIXBIAS of either 00h or 1Fh are the obvious values to use when converting Amstrad games, but I *really* don't like either of those settings. The pink and purple colours seem like they are practically unusable.
Yes, purple, and pink (color 5) really unusable, if i remember well it was useful in one or 2 games, but we have to live with it :D

I have spent the last few days working on the Gryzor loading screen, trying to get more comfortable with the different FIXBIAS values, and also editing the screen so that there are only 8-or-less unique non-FIXBIAS colours on each line of the screen.

Once I had results that seemed to look OK, then I figured out where to put some raster splits to add a few extra colours to the screen.

Here's the result (with 24 colours displayed), together with the Amstrad original for comparison.

Please note ... I'm not an artist, so this is about the best that I can do! ;-)
You could be an artist too :), the new picture is amazing,, color shades just perfect.
How many splits did you use on the screen?
Probably EPimgconv can help to find places of raster split also, by checking the generated LPT and it's colour definitions.
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.20. 09:38:38
How many splits did you use on the screen?

Thank you for the kind words! :)

If you right-click the image and save it, then you can open it up in an editor like ProMotion or Grafx2 and see where the raster splits are.

There are 4 different areas in the Enterprise image, and each uses a different 16-colour palette of the main 256-colour image (0-15, 16-31, 32-47, ...).

That's how we created game graphics in the 16-bit era for the PC Engine/MegaDrive/SNES.

To see the different screen areas, just alter colour 0, 16, 32, 48, etc and you will see the area of the screen that is used by that palette.

Encoding the screen in that way makes it both easy to edit, and easy to process it into an LPT and graphic data.
Title: Re: Converting old Ocean games
Post by: geco on 2020.April.20. 11:04:18
Grafx2 is cool ( i checked only that ) , and probably i will use it in the future instead of Paint :D and Gimp. When i wanted to create a splitted screen, i used paint, and divided the screen into x part to different files :D and at the end i converted the files by EPimgconv, and finally merged them :D
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.25. 06:13:37
hopefully fixbias will not cause any problem :)

The re-coloured Enterprise screen grab that I posted earlier is using a FIXBIAS-compliant set of colours, but I'm only finding a way to use at-most 6 out of the 8 colours for any of the FIXBIAS values that I've tried.

If I can't find an easy raster split, then I'll have to change some of the sprites so that they use one or both of the unused colours in the FIXBIAS set.


Damn ... FIXBIAS really does have a nasty effect on your colour options, especially when converting an Amstrad game that uses more than 14 colours on screen at a time! :roll:


If I use a FIXBIAS value of 07h then I can get a good match to the original Amstrad colours, and still have the ability to try to find some use for the otherwise "useless" bright pink that FIXBIAS forces on me.

I suspect that geco has found that it is one of the most useful FIXBIAS values when converting Amstrad games because you get both a usable shade of blue, and a dark grey that will often be a very good substitute for the Amstrad's darkest blue, which a lot of Amstrad artists used for dark shadows.

However, if I use the value of 07h then I don't believe that the game really looks much better on the Enterprise than on the Amstrad. I've edited the Amstrad graphics to try to take advantage of the different colours on the Enterprise, but the result still doesn't make me very happy.


The re-coloured Enterprise screen that I posted earlier uses a FIXBIAS setting of 09h, which results in a totally-different set of colours.

Unfortunately, when I use that setting, the useless purple colour that FIXBIAS forces on me means that I must remove one of the other colours in the game, there just aren't enough palette entries!

As much as I hate to lose it, I believe that if I use the 09h setting, then the best colours to merge are the yellow and white, and replace them both with the Enterprise's brightest-and-whitest yellow.


Whichever FIXBIAS setting I use, the game's entire graphics will need to be manually edited in order to get the best result on the Enterprise, because just swapping palette entries really doesn't give a good result.


Anyway, since a picture paints a thousand words, here is a visual comparison of the different options., with the original Amstrad screen on top.

Please note that both Enterprise screens have been manually edited to reassign some of the pixels to different palette entries.

(https://live.staticflickr.com/65535/49815960506_c6fd25c41a_o.png)
Title: Re: Converting old Ocean games
Post by: geco on 2020.April.25. 09:21:00
I like the bottom palette :-) i think bias 1Fh could give a bit better result than bias 07h for middle image, because it's colours are brighter, and it's pink is more usable. i had the same problem  with Renegade, finally i used 1Fh,  and changed cyan to gray, and used pink for i do not remember the name  of CPC color, but similar to it.
Title: Re: Converting old Ocean games
Post by: geco on 2020.April.25. 09:23:18
Both looking and visibility of bottom screen are very good.
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.25. 21:57:15
i think bias 1Fh could give a bit better result than bias 07h for middle image, because it's colours are brighter, and it's pink is more usable. i had the same problem  with Renegade, finally i used 1Fh,  and changed cyan to gray, and used pink for i do not remember the name  of CPC color, but similar to it.

I tried 1Fh, but honestly, it doesn't work well for Gryzor, because the arcade game has a lot of grey tones, and the brighter grey in the 1Fh set just causes havok with some of the other backgrounds.

It isn't dark enough to be a shadow grey, and it isn't bright enough to be the main "steel" grey.

On top of that, the blue colour that I'm using as the water starts to take on a purple tint with the 1Fh setting.

So IMHO, 07h is definitely the better setting for Gryzor's particular graphics (if we're keeping the "Amstrad" look) ... but that certainly doesn't mean that it's the right choice for all games.

I'll be very interested to see your results with Renegade when you're willing to post some screenshots!



I like the bottom palette :-)

Me, too ... it gives a good contrast between the backgrounds and the sprites, and the extra grey tones  look really good with the game's graphics.

It does a good job of showing the strengths of the Enterprise's large colour range ... but it also shows the cost of having the top 8 palette entries being controlled by FIXBIAS instead of being regular registers that you could set to any colour.

Anyway it definitely means that I have to edit all of the game's graphics to take advantage of the different colours, in just the way that we would have done so if we had developed an Enterprise version of the game back in 1988.
Title: Re: Converting old Ocean games
Post by: geco on 2020.April.26. 09:34:25
Sorry, i did not send you the CPC source either, but it is not perfect yet, and the stage of EP version is also early, the program is just running, graphics converted, music is there, but CPC addressing is also there, and between screen changes it change to a bad palette for a short time :)

Loader screen has bias 0, this is not the final version, because there are some purple pixels on the bodies, i edited it, and have the modified picture too, just not used yet.
[attach=1]

Game has bias 1fh
[attach=2]
Level1
[attach=3]
[attach=4]
Level2
[attach=5]
[attach=6]
level3
[attach=7]
[attach=8]
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.27. 10:02:23
Sorry, i did not send you the CPC source either, but it is not perfect yet, and the stage of EP version is also early, the program is just running, graphics converted, music is there, but CPC addressing is also there, and between screen changes it change to a bad palette for a short time :)

There's absolutely nothing to be sorry for!

Thank you for spending so much of *your* valuable free time working on converting one of *my* old games. :ds_icon_cheesygrin:

I'm just curious how things are going for you since it's becoming obvious that we have somewhat different approaches in trying to get an Amstrad  game working on the Enterprise. It's fun to see (from afar) how you're getting along with my horrible old code. ;-)


Loader screen has bias 0, this is not the final version, because there are some purple pixels on the bodies, i edited it, and have the modified picture too, just not used yet.

Those screen are looking really good! Great job! :cool:

The thing that I'm noticing in the screengrabs is that you're using the  FIXBIAS pink colour as the flesh tone for the sprites.

You've mentioned that before, and now that I have some actual experience of trying to get something working on the Enterprise, I have a better understanding of the problem that you're facing with re-colouring the game.

There's no easy, or perfect solution, is there? The Enterprise's FIXBIAS limitation really does seem to have a nasty effect on making games look great on the Enterprise, even though it has all those lovely 256-colours to choose from for the first 8 palette entries.

Title: Re: Converting old Ocean games
Post by: geco on 2020.April.27. 11:59:59
Thank you for spending so much of *your* valuable free time working on converting one of *my* old games. :ds_icon_cheesygrin:

I'm just curious how things are going for you since it's becoming obvious that we have somewhat different approaches in trying to get an Amstrad  game working on the Enterprise. It's fun to see (from afar) how you're getting along with my horrible old code. ;-)
I make it as a hobby, and i enjoy it :), I saw several solutions in the code what i did not see before, i think your code is much more sophiscticated than what i saw in later released games. I checked Target Renegade (only on youtube) and i am sure that you and the graphics guy who worked on Renegade could do much better game on CPC.

Now i had much harder situation, because you had an early stage source :) , and i played puzzle with the existing source and the source what i got from binary, but finally we have it :)

Those screen are looking really good! Great job! :cool:

The thing that I'm noticing in the screengrabs is that you're using the  FIXBIAS pink colour as the flesh tone for the sprites.

You've mentioned that before, and now that I have some actual experience of trying to get something working on the Enterprise, I have a better understanding of the problem that you're facing with re-colouring the game.

There's no easy, or perfect solution, is there? The Enterprise's FIXBIAS limitation really does seem to have a nasty effect on making games look great on the Enterprise, even though it has all those lovely 256-colours to choose from for the first 8 palette entries.
Thank you very much :) I was in big trouble in the beginning, i did not want to loose number of colours, but when i found the bias, and the result, it made me happy :)
Yes, this pink not the best, but gives quite good result, much better than loosing a colour :)
Unfortunately there is no perfect solution, nearly each game gives other problems with their palette, except 4 colour games :D :D And it would be good if there would be a possibility for 1 - 2 raster split, but in most cases there isn't. Now i could do, but as i saw the advantages could be used on level 2 only.

I totally agree with you, separate 8 colour palette register would be much better than 1 fixbias, but i think Nick chip would never be ready if they choose this solution ;)
Title: Re: Converting old Ocean games
Post by: szipucsu on 2020.April.27. 16:26:52
Anyway, since a picture paints a thousand words, here is a visual comparison of the different options., with the original Amstrad screen on top.
I suggest attaching images to the post. Under the window where you can type your post, attachments can be chosen. It is better than linking from another page because external pages can change their content or even stop working and the linked images may not appear here any more.
Title: Re: Converting old Ocean games
Post by: elmer on 2020.April.30. 02:21:17
Loader screen has bias 0, this is not the final version, because there are some purple pixels on the bodies, i edited it, and have the modified picture too, just not used yet.

Dang, that Renegade loading screen is a huge pain to get looking good on the Enterprise! :shock:

It would have been so much better (and infinitely easier) without FIXBIAS getting in the way.

Anyway, here's my attempt at a conversion, mainly in an attempt to get the background wall looking darker than in the screen that geco posted earlier.

There are 2 raster splits, but they don't really add a lot.

I'm not sure that this looks any better than geco's version, but I don't believe that there's much else that I can do to it.

[attach=1]


And here's a version in the light palette, which makes it possible to add a raster split for the girl's hair ...

[attach=2]
Title: Re: Converting old Ocean games
Post by: geco on 2020.April.30. 08:20:25
The ground looks much better in both version than in mine, unfortunately the green is tto much in the 1st, i am sure i will use the ground colours from the 1st or 2nd, and i will check which body colours looks better, the 2nd, or what i posted, now the 2nd seems to be better :)
Meanwhile i am in the finish with Renegade, Scrolling is working, unfortunately i could not increase the map without modifiying map tiles, i tried to use half of the 1st and the last Map tileset to increase the map, it worked well on the 1st level, but not on the others, so if the map reached the end during scrolling, it gets border color.
I want to modify 2 things, and test the game again if i did not add any error to it :D