CPCEC a new emulator from cngsoft

[cngsoft]

Can it use ParaDOS v1.2? / Remap keyboard?

Yes, all you have to do is to swap the default ROM files (AMSDOS and the original English-keyboard firmware) with your own ones. CPCEC will accept them as long as they're compatible, i.e. firmware is a 32k file where the first 16k is the BIOS and the last 16k is the BASIC, and the DOS ROM is 16k and includes a valid high ROM ID.

[cngsoft]

After posting a minor bugfix several days ago I'm already preparing the next major releases. On one hand, image interpolation is now based on three independent shaders whose effects pile up on the image.



On the other hand, extended memory (up to 32 ROM 16k banks and 8 RAM 64k banks) is the first step towards Amstrad Plus support. A very early step, but I can already see some screens and hear music...



When these features are ready, I'll get back to improving the overall compatibility of both CPCEC and ZXSEC, hoping to get the CRTC and FDC quirks and the ULA contention right sooner or later.

[cngsoft]

The past weekend's release was a rushed one, fixing the ZIP archive "read-then-write" bug and adding 576 kB RAM support but disabling the still minimal PLUS ASIC emulation.



Video filters can now be configured independently, together with the scanline and interlace modes, sometimes leading to interesting effects. I like X-Masking and Double Interlace on my laptop, but I prefer Y-Masking and Whole Scanlines on my desktop.



Plans for the near future include PLUS ASIC emulation for CPCEC, as stated in past messages, and memory contention for ZXSEC, where I'm rewriting the Z80 engine so it relies on macros that provide either "coarse" CPC timings (always aligned to 4 clock ticks and very predictable in their duration) or "fine" Spectrum timings (aligned to nothing and very volatile because of the address bus collisions) thus allowing both emulators to rely on the same Z80 files.

[cngsoft]

Before I get too busy with the CPC Retrodev compo, I updated CHIPNSFX, UZ80 and CPCEC with few news and many fixes:



* 20191004 -- Twelfth public release. Precise (albeit not perfect yet) memory contention and ULA noise ("snow") on Spectrum: "48K Timing Tests" passes all tests but 36 and 37, and "128K Timing Tests" fails on just six tests. "Mask 3: Venom Strikes Back" draws the attribute and border effects on their precise locations on all platforms (48K, 128K/Plus2, Plus3) and Software Creations' "Black Lamp", "LED Storm" and "Sly Spy" behave well on 128K machines. Improvements in the debugger: fixed disassembly panel invalid cursor locations, added optional tall characters, avoided debug+pause clashing, new key M toggles memory dump ROM+RAM and RAM-only modes. Improved ZIP handling (ZIP archives are no longer locked, files within archives are filtered by extension), user interface fixes.
* 20191004 -- Minor patch making the debugger options set with V and M stick between sessions.



I'd have liked to fix the CRTC bug that makes the recently released and spectacularly smooth "Pinball Dreams" unplayable but the deadline looms :-(

[cngsoft]

I just released a new version of CPCEC and its little sibling ZXSEC, mainly because I had to support "Pinball Dreams" in one way or another!




Instead of trying to develop all CRTC types at once I focused on CRTC 1. "Mission Genocide", "Warhawk", "Dynamic Duo", "Prehistorik 2", "From Scratch", "Batman Forever", "Imperial Mahjong", "Octopus Pocus" and many more work flawlessly now, instead of the fragile balance where some tweaks fixed some titles and broke others. Sadly, the fragile balance has now shifted to CRTC 1 against all the other types... so there's still a lot of work to do.




New options include a basic V-Hold control (now the original "Thunder Blade" release works) and a flexible H-sync mode that allows fine-tuning Gigascreen effects such as the "Batman/Spawn" screen in "Batman Forever" together with the already extant interlaced mode options.

ZXSEC also benefits from increased precision in memory contention timings, especially on 48K. There's no longer conflict between "Starion", "Dark Star", "Black Lamp" and others that were drawing special effects on the border and the attribute map at once.

[cngsoft]

Emulating the CRTC type 1 was the first step towards full "Pinball Dreams" support. CRTC 0 is now half done and some demos that either worked in early versions of CPCEC thanks to kludges ("Nayad" part of "5KB Demo 3") or didn't work at all ("Tantrum" part of "Face Hugger's Ultimate Megademo") are now fully operational. "Pinball Dreams" itself still resists, though.

[Ast]

Hi César,


To complete your crtc 1 emulation, try to make runable Scroll Factory.


It would be a good challenge for you and a good way to make your cpcec better.


Have a good fun.

[cngsoft]

Hi César,

To complete your crtc 1 emulation, try to make runable Scroll Factory.

It would be a good challenge for you and a good way to make your cpcec better.

Have a good fun.

Good suggestion. This is how it looks like right now:





CPCEC simulates a 2 NOP delay on MCR changes (Imperial Mahjong needs either 2 or 3 NOPS to behave properly); if I set the delay to 0 or 1, the title of Scroll Factory improves:



I'm going to have to ask so many questions about the internal delays that happen between the Z80, the Gate Array and the CRTC. I better start writing them down already.

[cngsoft]

I released yesterday morning a new version of CPCEC, but it's a minor patch fixing bugs such as bad window rendering when the screen isn't tall enough (for example my current laptop), recording the wrong value in the bytes/second field of WAV files, or failing to keep OUT &0088,&88 from going to the Gate Array ("Knight Rider"). The FDC can now format tracks, a feature that I had dummied out until I was advised to enable it.



"Still Rising" (CRTC 0 and 1) and "Octopus Pocus" (CRTC 1) join the list of CPC demos that work. "PhX" temporarily loses sync in two different parts depending of the CRTC type. "Pinball Dreams" doesn't run on CRTC 0 or 2 yet, but it works well on CRTC 3 and 4, although only because the game expects them to behave like CRTC 1 regarding the "buffered" CRTC registers 4, 5 and 9. This goes against Shinra's document "Differences between CRTC types" stating that CRTC types 3 and 4 are like CRTC 0 and 2 in this aspect. Who's right?

[Ast]

Hi @cngsoft


I've just tested CPCEC right now. There's still some work to do on Scroll Factory's intro.


Your emulator begins better and better each day. Do you plan adding Amstrad Plus emulation ?

[cngsoft]

A change in the behavior of REG1 finally makes the level start SFX of "Zap't'Balls advanced edition" work properly and improves "Onescreen Colonies":

Hi @cngsoft

I've just tested CPCEC right now. There's still some work to do on Scroll Factory's intro.

Your emulator begins better and better each day. Do you plan adding Amstrad Plus emulation ?

Scroll Factory is indeed still incomplete, as I showed in the past screenshots. Either the mode change happens too late or the video rendering happens too soon. I know that there's a delay between what the Z80 does and what the screen shows, but I don't know its nature and its length, or whether it's just one delay or several types of it.

Amstrad Plus is in the queue too, and in a past message I posted a screenshot of "Burnin' Rubber" running on incomplete ASIC emulation.