Release of Amstrad Cpc Crtc Compendium (and Amazing Demo Rev 2021)

[Longshot]

Hello

A new version of the Compendium (v1.4, 269 pages) is available here:
http://logonsystem.fr/down/ACCC1.4-FR.pdf

The English version is under review.
Thanks to Marc for his remarkable work.
BSC, be patient !!

The chapters relating to the "Interlace" mode, as well as several concepts relating to the VSYNC signal (e.g. a single-line lag in certain situations), have all been reviewed in depth.

The chapter on "tips & tricks" has been largely enriched (10 sub-chapters).

A new chapter dedicated to "fixed-time development techniques" has been added.

These techniques are one of the cornerstones of the work carried out to create the Compendium.

This new chapter is also a way to introduce the use of a CPU calculation function, described in the document.

SHAKER 2.3,  developed with the help of this calculator, is available on the logon system portal.
( 80 kb with 4 modules).

Results of the SHAKER 2.2 tests can be accessed here: https://shaker.logonsystem.fr/

I would like to take this opportunity to thank DManu for our positive, collaborative work.
Much more accurate than any other CPC emulator, AMSPIRIT perfectly simulates the "Gate Array/Z80/CRTC" trio of the old generations of CPCS for CRTCs 0, 1, 2, and 4, including all of the "Interlace" functions (unjustly ignored so far ).

[andycadley]

Cool. Looking forward to an English translation as the French is a bit beyond me. Really good technical documentation though. Hopefully we'll end up with definitive docs of how the different CRTC variants work and get better emulation and even more cool tricks as a result.

[GUNHED]

Great thing for people who want to get into CPC coding more seriously. 

[SerErris]

Hello

A new version of the Compendium (v1.4, 269 pages) is available here:
http://logonsystem.fr/down/ACCC1.4-FR.pdf

The English version is under review.
Thanks to Marc for his remarkable work.
BSC, be patient !!

Are we there yet ? ... 

[BSC]

Are we there yet ?

Please be patient!

[martin464]

Learning French is easier than programming crtc, by the time you know crtc coding you will know all the French swear words too!

[Animalgril987]

I already know one French swear!

[Apollo]

Learning French is easier than programming crtc, by the time you know crtc coding you will know all the French swear words too!

Learning French for 3 years as 3rd language in school, I disagree respectfully!

[zhulien]

Dragonbreed Wetware announced their second demo would include the first example of vertical rasters - but the demo never came out (as far as I know) - are you aware of that and is it possible?

[megachur]

Hello,

Is it what you called 'vertical raster' ?

example : https://www.cpc-power.com/index.php?page=detail&num=9101


Technicaly : The rasters are only horizontal. but we can get pixels on the screen that look like vertical rasters ;-)!

example : https://www.cpc-power.com/index.php?page=detail&num=7743

[redbox]

Dragonbreed Wetware announced their second demo would include the first example of vertical rasters - but the demo never came out (as far as I know) - are you aware of that and is it possible?

I think they meant vertical rupture.

Maybe you could ask PowerHowse from Dragonbreed?

[Longshot]

Hello

A new version of the Compendium (v1.5, 282 pages) is available here:
http://logonsystem.fr/down/ACCC1.5-EN.pdf
http://logonsystem.fr/down/ACCC1.5-FR.pdf

The document updates for version 1.4 and 1.5 in English have not yet been checked and corrected by Marc.
Thank you for your indulgence.

I will put online the version corrected by Marc once available.

The chapters relating to synchronization have been reviewed in depth, in particular on the nature of the CSYNC signal sent to the monitor by the GATE ARRAY.

The chapter on the states of CRTC's 3 & 4 has been updated with the identification of new states.

SHAKER 2.4 will soon be available on the Logon portal (....Be patient ).

SHAKER now demonstrates that it is possible to achieve smooth horizontal hardware scrolling in 1 pixel mode 0 and 1 pixel mode 1 without resorting to double buffering.

Results of the SHAKER 2.2 tests can be accessed here: https://shaker.logonsystem.fr/ 

 
The next version of the Amspirit emulator, developed by @DManu, reaches new heights of precision.
Amspirit should in particular consider the work on the composite signal and its management by the CTM. 
No emulator until now was able to handle an in-line CSYNC.

[GUNHED]

Thanks for putting lots of work and effort in it!!! 

[Longshot]

SHAKER 2.4 is now available on the Logon portal:
http://logonsystem.fr/html/downloadlogon.htm

The add-on disk (SHAKER_ADDON.DSK) contains two little programs:

- An example of a vertical rupture for all crtc's (already presented with 2.1).
- An example of an hardware horizontal scroll at the pixel level in graphics mode 1.

[Anthony Flack]

That scrolling is amazing, is there a catch?

[SyX]

For game developing, of course there is a catch, you need to sustain the fx in every scanline that you want that fx.

Aside of that, you need extreme timming accuracy, because you need to set R3 = 5 and then R3 = 6 during the HSync period (that simulate the display shift per one pixel).

Of course, you can not forget, that your screen is going to shake one pixel  in horizontal, then you need to blank those columns if you can not hide them outside the screen borders (take a look to the AMAZING Relentless in Winape with "show interrupts" enabled).

And last, if you are using a HUD after the scroll zone, then you need a few scanlines between the zones for letting the CRTC resynchronize again and the start of your HUD is not shifted by the display resynchronization.

It is not impossible, but your engine need to be built around these limitations.