[Amstrad CPC] Commando

[bonnefoi]

Hello,

Do you think that fixing the Commando screen artefacts could be possible ?

best regards, Pierre-François.

[renaudhelias]

Commando's screen atefacts seems due to Z80 implementation (instruction speed, instruction quality). I have a Z80 testbench, and it does fail a lot (but it is my favourite Z80... ^^')

[bonnefoi]

Do you have taken a look at the A-Z80 core by Goran Devic ? You have already succeeded to use external memory so perhaps you could try another core... :)

[sorgelig]

A-Z80 is more far from Z80 replica than T80. I've started my ZX core with A-Z80 and later found many problems. Some instructions aren't correctly implemented. Timings are also not correct. Author of A-Z80 claimed it's based on chip decaping, but i think it's not true according to bugs i've found.

[renaudhelias]

A-Z80 was allready tested on CoreAmstrad, it is worse. That is certainly due to the fact I did progress my project with T80 ¤ But if it is worse, so then it is "different". That's a interesting fact, A-Z80 is using a different approach than T80. T80 is a translate from MAME one if I know enough the author of it. A-Z80 seems a full-hardware approach, using low level set of components as a gallery of ants, and ... does run. Facing each other shall be a great and cool way to progress.

¤ I shall have to retest 20000 games from begin, in current project I allready have my "selection of known running cool games"...

[renaudhelias]

Let's, for the fun, try Commando with A-Z80. I turn on the parameter : USE_AZ80:boolean:=false; in FPGAmstrad_amstrad_motherboard.vhd Compiling...

[renaudhelias]

Testing...

[renaudhelias]

Does boot...

[renaudhelias]

CRTC:1/MEM_wr:quick : KO (normal quick is not original) CRTC:1/MEM_wr:slow : KO CRTC:0/MEM_wr:slow : KO CRTC:0/MEM_wr:quick : KO Exactly as on CoreAmstrad (damn !)

Game test : -Moktar : KO - some problems while reaching bottles (this is my best friend favorite game...) -Star Sabre (a 2009's game) : OK -Sim City : INTRO HACK DEMO DOES PASS PERFECTLY USING A-Z80 and NOT WITH T80 (2/3 of luck) -Edge Grinder (squeeze screen bug in CoreAmstrad) KO, same -Pinball Dreams (recent game maked by Batman group !) - freeze with MEM_wr=slow, DOES RUN WITH MEM_wr=quick (as in CoreAmstrad)

OK, next challenge, DEMO (It is known as testbench booting, detecting and rage quit if something is bad emulated... forcing as it buying the original CPC ^^). Using CRTC1/MEM_wr:slow -30YMD (not running so fine in CoreAmstrad, and in a lot of emulators) : rage reset, directly. -the legendary Batman Group's demo (running not so badly in CoreAmstrad) : first part : PERFECT sound/PERFECT graphics, second part : quite GOOD -MEGABLASTERS death (in CoreAmstrad it does run) -Points barres : first part OK, second part KO (as in CoreAmstrad), crash. -Midline Progress (not running in CoreAmstrad) KO (normal it is made by god itself : ARKOS, certainly a FDC bug) terrible crash, even the reset button of MiST does nothing, and received an electric choc touching the platform. -From Scratch (oh oh oh) does crash (as in CoreAmstrad damn it !)

And MUSIC (cause CPC has an Yamaha chip inside, respect) : -STARKOS (by ARKOS) - the CPC best soundtracker ever, MEM_wr=slow, CARPET.SKS => PERFECT (too perfect ?)

And ROMs : -PROTEXT ok

[renaudhelias]

TODO-list updated (http://www.cpcwiki.eu/index.php/FPGAmstrad) just do search "A-Z80" on this manifest. Good job, well done, a lot of thanks to you guys !

[renaudhelias]

¤ in fact, small electric choc comes from my speakers... just have to turn then on after turning on MiST-board (I currently have a very very old electronic installation........)

[renaudhelias]

Can be closed, commando is already in TODO-list.

[renaudhelias]

do play Ikari Warriors instead ^^

[bonnefoi]

Ikari warriors :D it's too damn hard for me ! thank you for trying with A-Z80 👍

[sorgelig]

The most important (and sad) fact is: there is no Verilog/VHDL exact replica of Z80... All Z80 modules are based on known functional model and don't include very specific less documented nuances.