CPC games with ZYDROLOAD Protection

[dlfrsilver]

Hello Guys, i have finally made the first game with the zydroload protection scheme.

In fact it's pure Spectrum, and you must use TAPER, the spectrum tool in order to
get the zydroload data working. and strangely, this loader use 2 or 3 headers before the main blocks
of the game. that's why samp2cdt can't cope with it it only sees the header but not main block right
after it.

Have fun

[Gryzor]

Huh? I must admit, I haven't heard of Zydroload before!!! How does it work? How did you do it? And, interesting, what do you mean "it's pure Spectrum"?

[dlfrsilver]

Huh? I must admit, I haven't heard of Zydroload before!!! How does it work? How did you do it? And, interesting, what do you mean "it's pure Spectrum"?

Zydroload is a K7 protection scheme used on 3 games on CPC :

North and South, The light corridor, and hostages - Operation jupiter.

This loader is not a CPC one, but one coming from the Spectrum world.
I mean that none of the actual CPC is able to deal with it.

TAPER can however. thoses games have the pilot tone, length, and bits x stored INSIDE
the data blocks.

they use a standard CPC loader and then Spectrum data handling (Pure Spectrum).

The CPC version of Zydroload is the same as the one used on Spectrum versions of the games. I have used Light corridor spectrum version to see how it is.

Pure spectrum like Toyota Celica Gt rally, Lotus turbo challenge, and supercars from Gremlin.
Those 3 also use a Pure spectrum protection scheme.

[Cholo]

Hi dlfsilver!
Thats some great news there. Especially as i managed to get my hands on a copy (original) of Hostages a short while ago and in order to make a cdt ill have to retrace your steps on how to do it properly 

[AugustoRuiz]

Hi!
Zydro is a member of computeremuzone forums... He was a developer at the company that made Spectrum conversions of some french CPC titles, called New Frontier (like those cited above), and he developed Zydroload...
Maybe you can post a message at the "New Frontier Unplugged" thread at CEZ forums, where he answered some questions...
Cheers!

[dlfrsilver]

Hello Augusto, i'm sorry, but i don't speak spanish

[dlfrsilver]

Ok peeps, i have found a STABLE way to convert Games using Zydroload

1) Dump your tape as *.voc 22050khz 8bits mono
2) Use taper, and convert without any flag(none), click OK
3) save as TZX file, like game.tzx
4) Use samp2cdt to get the amstrad CPC loader, save
as game.cdt
5) Use TAPIR, load in it game.cdt, remove all spectrum blocks that are anyway badly decoded.
6) In the file menu use APPEND ;
7) load Game.tzx
Remove all useless bits/blocks in game.tzx and KEEP
the Spectrum blocks !!!
9) Save the whole thing by doing SAVE in file menu
10) launch with CPCE and it works !!!!

It works with hostages, so please find below the link
giving access to it :

http://www.phenixinformatique.com/CPCGAMES/pages/download.php?fiche=1109&dsk=9

Have fun, North and South is prepared and 100% tested,
i have finished it :

http://www.phenixinformatique.com/CPCGAMES/pages/download.php?fiche=138&dsk=8

[Cholo]

Great thanks 
Never would have figured that i must admit 
Gonna try and make a dump right away and see what happens.

[dlfrsilver]

You have The light corridor ? If yes would be nice yes to try converting it for us.

In case of trouble, please upload the VOC file, i will convert it

[Cholo]

You have The light corridor ?

Dont recall having the game, so unless its hiding inside a multiple games pack somewhere (i havnt checked those fully) then i aint got it.

Did get Hostages to work right away tho. Thanks again for the information 

Edit: oh and i was suppriced how well the amstrad version is compared to the amiga 500 one. Played the amiga game a lot back then and it seem that even the intro and music is there too on the amstrad. Petty cool.

[dlfrsilver]

Yes it's excellently converted it's brilliant port from the atari st version in fact

Adn yes Hostages convert 100% top with this method

[specfreak]

Hi folks.  It's been a while since i've been here and they've changed the forum ;-).

Yer, we recently re-TZXed a number of Zydroload games on the Spectrum for the TZX Vault and WoS.
Seems Taper can decode them quite well.

More info on Zydro can be found on my Schemes page, I should probably start a CPC one, although I have to admit that most info is from a guy called Mikie based in the Czech Republic and I wouldn't know how to obtain these timings:
http://newton.sunderland.ac.uk/~specfreak/Schemes/docs/zydroload.html

I wonder if ODELoad could be CDTed in a similar way to the spectrum ones.  I'd be interested in seeing a v1.20 CDT in line with the TZX update spec.  I know Generalized Data block (id.19) caused a stir, but it might be able to store some trickier loaders like maybe Bleepload v3.

I'd best go and read up what's happening around here.

Best wishes

Andy Barker (8-bit Preservation team, TZX Vault, World of Spectrum)

[Gryzor]

Hello SpecFreak,

Yes, quite a few things have changed around here... and it's really nice to see you dropping by

I read your page and, amazingly so, just by reading the sound description I knew which protection it was! I find it really intriguing that we're still going after protection schemes so long down the road...

[dlfrsilver]

Hi folks.  It's been a while since i've been here and they've changed the forum ;-).

Yer, we recently re-TZXed a number of Zydroload games on the Spectrum for the TZX Vault and WoS.
Seems Taper can decode them quite well.

More info on Zydro can be found on my Schemes page, I should probably start a CPC one, although I have to admit that most info is from a guy called Mikie based in the Czech Republic and I wouldn't know how to obtain these timings:
http://newton.sunderland.ac.uk/~specfreak/Schemes/docs/zydroload.html

I wonder if ODELoad could be CDTed in a similar way to the spectrum ones.  I'd be interested in seeing a v1.20 CDT in line with the TZX update spec.  I know Generalized Data block (id.19) caused a stir, but it might be able to store some trickier loaders like maybe Bleepload v3.

I'd best go and read up what's happening around here.

Best wishes

Andy Barker (8-bit Preservation team, TZX Vault, World of Spectrum)

Hello Andy,

The Zydroload scheme on CPC is exactly the same as the one used on
Spectrum. The timings doesn't matter since i have done some tests,
which shows that when converted back to WAV, it loads 100% ok
on a real CPC.

We have done with CNGSOFT Trivial Pursuit and Gazza II which uses both
UNIlode. The sequence required is known, and for TP the main block is pure
data, without pilot, only bits 0 and 1.

[dragon]

As i take a look to the nort & south tape...

Really the protection is a pain  .

Because they load small blocks 0f &0200 lenght. In diferent places. So only to load the map is equivalent to have 18 files diferent to load in the memory : p.

[Joseman]

As i take a look to the nort & south tape...

Really the protection is a pain  .

Because they load small blocks 0f &0200 lenght. In diferent places. So only to load the map is equivalent to have 18 files diferent to load in the memory : p.

If i remember correctly the bleepload protection do something similar, on every "bleep" the destination mem can be a different direction because is specified every time, technically it can write on any part of memory docens of times. The game i tried (usagi yojimbo) didn't make use of this feature and the memory was contiguous on every bleep, but if they want to they can convert on a nightmare this protection

[dragon]

Yeah i have anoted these:

1º fist load from basic &4000-8bd3
2º &7000+442E=B42E INFROGRAMES draw+loader.
3º turbo load 0100+7C56=7D56=c1(cx is the number of .bin to the cartridge).
4º &C000 A &3FFF  =c2

game run in &jp100

5º &c000 a &3fff =c3 (introduction)

6º&5800+1d40=7540-1 =c4 (choose keys).

7º choose dificulty:&0200+62CE=64CE-1 =C5    &8000+3FFF=BFFF-1 =c6

8º load map (the nightmare). &0000-&0800-1 (c7) &0800+&7779=7f79-1(c8) 8000+17e8=97e8-1 (c9)
----&8600-0200=8800-1 (c10) 8e00+0200=9000-1(c11) 9600+0200=9800-1 (c12) 9e00+0200=a000-1 (c13)
----a600+0200=a800-1 (c14) ae00+0200=B000-1 (c15)  b600+0200=b800-1 (c16)  be00+0200=c000-1 (c17)
----c600+0200=c800-1 (c18) ce00+0200=d000-1 (c19) d600+0200=d800-1 (c20)  de00+0200=e000-1 (c21)
----e600+0200=e800-1 (c22)  ee00+0200=f000-1 (c23)  f600+0200=f800-1  fe00+0200=0000-1 (c24)

lol.

I found these from spectrum:
Zydroload

To find where zydroload is write in ram, is easy as search the ld ix,0000 de,0000.

Subrutine overwrite it with the  ix memory loading begining point and de lenght of copy-1, when load the indicator from tape.

So made a break point in the ix line, reveals you all loads from tape/write to memory. Loading the tape.