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Vespertino - new game from BG Games

Started by XeNoMoRPH, 15:17, 05 May 19

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ervin

#125
Quote from: AHack on 09:01, 14 May 19

My GBC games are:

Cool Bricks
Mia Hamm Soccor Shootout - I'm pretty proud of this one for the fact that it can screw the emulators (when they were first been developed) as I did a Hi-colour screen by racing the LCD.
European Super Leauge
Thunderbirds

Tremendous, I'll check them out shortly!

[EDIT] Very cool!
How was the GBC to code?
Regarding the hi-colour screen, is that the title screen for Mia Hamm?
Also, the graphics in Thunderbirds are lovely.

AHack

Quote from: ervin on 10:07, 14 May 19
Tremendous, I'll check them out shortly!

[EDIT] Very cool!
How was the GBC to code?
Regarding the hi-colour screen, is that the title screen for Mia Hamm?
Also, the graphics in Thunderbirds are lovely.


The GBC had it's quirks but it was weird using a cut down Z80 like CPU to program with. It did have some handy instructions added like ld r,(hl)+. It was basically a tiled and sprite system where the CPU set registors and things happened with the hardware, so you were not concerned about making graphic routines with the CPU. And it also had DMA to help with transferring data around. It was probably the last system where games had to be written in assembly language to get the best from the hardware.

keith56

#127
I have Gameboy/GBC ASM programming videos on my Youtube Channel, for anyone interested in comparing the Gameboy to Z80
To get back on topic, I'm pleased to see the apparent interest Vespertino is gaining, even from the non-CPC community - it's nice to see people interested in technical achievement - and hopefully we can all learn something new about the CPC in the process!

Personally it's inspired me to take another look at CRTC tricks, and learn a bit about the rupture trick.
Chibi Akumas: Comedy-Horror 8-bit Bullet Hell shooter!
Learn ARM, 8086, Z80, 6502 or 68000 with my tutorials: www.assemblytutorial.com
My Assembly programming book is available now on amazon!

AHack

Quote from: keith56 on 22:17, 14 May 19
Personally it's inspired me to take another look at CRTC tricks, and learn a bit about the rupture trick.


There is plenty of info about how to do basic ruptures but there is very little about line to line ruptures and how to make it work on CRTC type 2. If you can do a full extensive tutorial on all the rupture tricks with example code then you will be doing a great thing for the community!

ukmarkh

Quote from: AHack on 05:02, 14 May 19
This is speaking for myself as a developer with a current CPC project on the go. I don't expect to make money programming an old 8bit computer as I'm not motivated to do so. I'm doing this for reasons of nostalgia from my childhood as it was the first computer I learnt to code on. With all the CRTC tricks that were discovered after it's commercial use you realise that games back when the machine was first launched really never used it's full potential so for me it's interesting to see what games could of been made if the CRTC tricks were known from the word go. And last but not least it's interesting going back to a machine where every CPU cycle makes a big difference and over the years I miss that type of programming challange - my last commercial machine code game was in 2000 for the Gameboy Color.

Hi, this is great to hear, and exactly the thing I'm talking about with regards to the CPC community. The CPC is the wrong platform if anyone is looking to get paid for their efforts, the motivation for putting together a new game on this beloved computer is that we had one as kids and it's interesting to see what games could have been made, and the technique used to help games sing, constantly pushing the hardware, man vs machine. I hate the idea of a subscription service, that gives exclusive access to developer content, locking other people out, but unless we can come up with another way to say thank you, and that's what it is for me, a method or platform to thank people for their time and effort. I purchased the new R-Type 128k because words alone didn't feel like enough, I love that game so much, a real labour of love, so I think what I'm saying is their just needs to be that option or donation button if you like for people to say thank you. I'm waffling now, but I hope people understand where I'm coming from.


Sent from my iPhone using Tapatalk

keith56

Quote from: AHack on 09:24, 15 May 19
There is plenty of info about how to do basic ruptures but there is very little about line to line ruptures and how to make it work on CRTC type 2. If you can do a full extensive tutorial on all the rupture tricks with example code then you will be doing a great thing for the community!
I'm hoping to do something, but the trouble is I'm nowhere near the smartest person on this topic, so I don't think I can do more than the basics at this time - I'm hoping I can learn more on the subject though
Chibi Akumas: Comedy-Horror 8-bit Bullet Hell shooter!
Learn ARM, 8086, Z80, 6502 or 68000 with my tutorials: www.assemblytutorial.com
My Assembly programming book is available now on amazon!

BSC

Quote from: AHack on 09:24, 15 May 19

There is plenty of info about how to do basic ruptures but there is very little about line to line ruptures and how to make it work on CRTC type 2. [...]


And that is actually a real shame. I really don't want to be finger pointing or embarrass anyone, but I wonder why not a single good tutorial (at least afaik) has been made
by any of the experts of CRTC wizardry around. Most of the tricks have been around for a while now (even taking the new things introduced around the Batman Demo era
into account) and I am sure that a lot of people (including me) would highly appreciate if someone made a howto on tricks like line to line (or many per line) split and I am
also convinced that it would boost interest in CPC (mainly demo) coding in general and also and help newcomers and people from other platforms to start coding for the CPC.
I must admit that I am way too lazy to do CRTC reverse engineering and I appreciate the amount of dedication and time(!) the veterans have spent exploring that area, but
the demo and retro computing scene in general should be much more about sharing and much less about secretiveness. Sharing is caring :)

** My SID player/tracker AYAY Kaeppttn! on github **  Some CPC music and experiments ** Other music ** More music on scenestream (former nectarine) ** Some shaders ** Some Soundtrakker tunes ** Some tunes in Javascript

My hardware: ** Schneider CPC 464 with colour screen, 64k extension, 3" and 5,25 drives and more ** Amstrad CPC 6128 with M4 board, GreaseWeazle.

ukmarkh

Here's a post from Arnoldemu about it... in case you haven't read it. http://www.cpcwiki.eu/forum/programming/rupture/

At the weekend I wondered when the first cpc game with rupture was made.

I found some interesting things (or maybe re-found) that could explain some things:

ACU, Jan 1988.
ZZKJ has an article about 32K screen. He mentions how to do rupture but I think he has experimented and doesn't fully know what is going on.

"..However, by sending an illegally large value to register 7 for the top frame the 6845 gets confused into omitting frame flyback, which gets rid of this band, and it just joins the top screen into the bottom if you position them correctly...

In a later ACU in july of that year there is an article for rim runner:

"
Although the Amstrad has a hardware scroll, it is useless here because it affects the whole screen. I needed to scroll different areas of the screen by different amounts, so what's the fastest software scroll?
Well, two articles in ACU, one by ZZKJ and one by Justin, suggested two possible approaches.
In his article on 32-row text screens on the Amstrad (January 1988), ZZKJ showed how to fool the 6845 video chip into displaying two separate screens together at once. OK, thought I, let's try giving different hardware offsets to the two screen sections. Then part of the screen will hardware scroll and the rest won't, right?
Wrong. This is one straw too many for the poor 6845, which promptly has a nervous breakdown. I couldn't find any combination of register values which worked consistently on one machine, let alone on different Amstrads. It meant giong back to the drawing board...
Justin's Scroll (June 1987) is the one I used. This employs the Z80 block move instruction to shunt all the screen data along, but uses a whole sequence of single LDI instructions (16 clock cycles per byte shifted) instead of a single LDIR (21 clocks per byte)."

There appear to be only two games that have rupture before 1988:

"Energy Warrior" which is not true rupture, the vsync happens twice.

"Mission Genocide" which is true rupture.

I wonder if the ACU article was the inspiration for people to try it. Does anyone know of any other articles in amstrad magazines that mention the rupture method?




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AHack

#133
I remember when Mission Genocide came out. I was so impressed with how smoothly it scrolled that I broke into the code and reversed engineered how it worked. From what I remember Paul Shirley used a lot of firmare functions and all the interrupt handling was via firmware. The graphics of the game were nothing special. The sad thing is by 1988 a lot of programmers had moved onto the 16bit computers so it was probably too late to use the Rupture tricks for viable commercial games.


The fact is that if those tricks had been known in 1984 by programmers then we would of been living a different history. The CPC would of been more close to the C64 than the Spectrum and potentially out do the C64 at certain games. The Spectrum coders were pretty clever on how to get the best from the Z80... imagine that practice on the Amstrad with hardware assist with the CRTC and you potentially move away from what the C64 could do and the Amstard would of shined, instead of the crappy Spectrum ports.


And now we are in 2019 and the Amstrad has more untapped potential then any other 8bit computer. For retro hobbyist programmers the Amstrad CPC has become an interesting platform because the Spectrum, Atari 800 and C64 machines have been mined more or less to their full potential... it would be pretty hard to do something on those platforms that has not been done to death over the years. And yet the Amstrad is sitting there untapped.

AHack

The disadvantage for the CPC was it's bitmap screen. Scrolling games were pretty aweful on it because the Z80 had to shunt the data around - most people to this day believe the machine is terrible at scrolling when in fact it is not. But with hardware assist, with the CRTC, it becomes it's main advantage because every single pixel can have it's own colour and games can look more vibrant with the colour choices the CPC has to offer.


The Amstrad can out do any 8bit platform for vertical scrolling games - just look at the Pinball Dreams conversion. And in recent years there have been some good horozontal scrolling games. I find it funny when C64 users see another 8bit out perform the C64 that they always say the sound is crap and we have the SID chip. Well, I like to think the C64 has really drab colours and a restrictive char based screen. As for the sprite handling you don't get many colours for the sprite. On an Amstrad sprites have to be done in software but they can also be pretty fast with compiled/UFD techniques with every pixel having it's own colour choice. Graphically the Amstrad is very strong. Anyway, joking aside about C64 users (I love that machine as well) the Amstard is like the forgotton child of the 8bit computers - people just dismiss it and say it cannot scroll smoothly.

Rhino

Quote from: Prodatron on 23:59, 06 May 19
This is so fucking cool, I am completely impressed, love this preview so much!  :o :P This is showing the pure power of the CPC, it is just fantastic!
What's about the new Tesla Roadster, I am sure, they will not sue you, but even promote it  :D
Impressive that Tesla!, the cars of the teaser are provisional but we want to give some surprises with the cars that we will include at the end :)

Rhino

Quote from: AHack on 09:24, 15 May 19

There is plenty of info about how to do basic ruptures but there is very little about line to line ruptures and how to make it work on CRTC type 2. If you can do a full extensive tutorial on all the rupture tricks with example code then you will be doing a great thing for the community!
For crtc 2 it is usual to use two-lines ruptures instead of line to line and if what you want is to repeat the same scanline, r9=0, r1>r0 also works on type 2.

AHack

Quote from: Rhino on 17:06, 17 May 19
For crtc 2 it is usual to use two-lines ruptures instead of line to line and if what you want is to repeat the same scanline, r9=0, r1>r0 also works on type 2.


Thank you for the information! I hope one day that the CRTC experts document all these techniques for the community to learn from. When I get a bit of time I would like to experiment with the CRTC. I think why this should be documented is because most users only own one Amstrad CPC and it makes it difficult to test on the different CRTC types - espesially with crucial timings.


Hopefully oneday this will happen.

roudoudou

Quote from: AHack on 18:03, 17 May 19

Thank you for the information! I hope one day that the CRTC experts document all these techniques for the community to learn from. When I get a bit of time I would like to experiment with the CRTC. I think why this should be documented is because most users only own one Amstrad CPC and it makes it difficult to test on the different CRTC types - espesially with crucial timings.


Hopefully oneday this will happen.
It's documented since decades...
...in french oups!
My pronouns are RASM and ACE

AHack

Quote from: roudoudou on 19:24, 17 May 19
It's documented since decades...
...in french oups!


:D


Any chance of someone converting over to English? A lot of English homebrew developers would really like this to happen - I tried a few French forums with google translate and it's not the best way to read technical stuff.

Rhino

Quote from: roudoudou on 19:24, 17 May 19
It's documented since decades...
...in french oups!
I'm curious to see that French docs, can you put the links?

Ast

Simply look at Amstrad Plus Forum.... May you find what you are looking for...
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All friends are welcome !

roudoudou

Quote from: Rhino on 11:04, 18 May 19
I'm curious to see that French docs, can you put the links?
I will tomorrow (only my phone until then)
My pronouns are RASM and ACE

XeNoMoRPH

your amstrad news source in spanish language : https://auamstrad.es

roudoudou

Quote from: Rhino on 11:04, 18 May 19
I'm curious to see that French docs, can you put the links?
https://amstradplus.forumforever.com/t283-Dossier-Rupture.htm
Mostly handwrittent letters (i said decades  ;D )
We plan to compile a proper version in english on a new doc website (no deadline)
My pronouns are RASM and ACE

AHack

Quote from: roudoudou on 21:46, 19 May 19
https://amstradplus.forumforever.com/t283-Dossier-Rupture.htm
Mostly handwrittent letters (i said decades  ;D )
We plan to compile a proper version in english on a new doc website (no deadline)


Those docs look fascinating, even though I cannot read them. I cannot wait to read the information in them on the planned website. Thank you to the people who are doing this, making that information available to all.

pelrun

#146

I just spent an hour running the Ramlaid docs through tesseract-ocr, with pretty good results - see attached. Google Translate makes short work of it. I'll do the Paradox document another day, I've done enough proofreading of foreign language recognition results for one day.


I've also been working through the old Logon System articles in Amstrad Cent Pour Cent for the past week with the same strategy. Now if only the listings hadn't been mangled several times by the publisher...


(Edit: I've reworked Ramlaid's doc and it's available on https://github.com/pelrun/cpc-demo-tutorials now. Good thing, because I completely screwed up the page order the first time...)

Rhino

Quote from: roudoudou on 21:46, 19 May 19
https://amstradplus.forumforever.com/t283-Dossier-Rupture.htm
Mostly handwrittent letters (i said decades  ;D )
We plan to compile a proper version in english on a new doc website (no deadline)
Although I don't understand them, but those Overflow and Madram manuscripts are pure gold :)

keith56

Quote from: pelrun on 13:25, 20 May 19
I just spent an hour running the Ramlaid docs through tesseract-ocr, with pretty good results - see attached. Google Translate makes short work of it. I'll tdo the Paradox document another day, I've done enough proofreading of foreign language recognition results for one day.

Fantastic work, I'm reading the Google-Translated version now, it's worked really well.
Chibi Akumas: Comedy-Horror 8-bit Bullet Hell shooter!
Learn ARM, 8086, Z80, 6502 or 68000 with my tutorials: www.assemblytutorial.com
My Assembly programming book is available now on amazon!

pelrun

I've just finished cleaning up Gozeur/Paradox's rupture tutorial, you can find it here: https://github.com/pelrun/cpc-demo-tutorials/blob/master/Paradox/paradox-rupture.md


Absolutely no warranty given for the accuracy of the text; OCR and a french spell checker helped get it close but I can't speak a word of that language (wait, I lied. merde.), so it probably put some very wrong accents in places.


The Logon System articles from Amstrad Cent Pour Cent are also in that repository, but they aren't fully edited yet. Some listings work, some are hopelessly broken.

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