Not working Amiga Protections

All questions about how to use KryoFlux go here.
PARALAX
Posts: 10
Joined: Sun Mar 25, 2012 8:32 pm

Not working Amiga Protections

Post by PARALAX »

I got the KryoFlux hardware several weeks before and could test now a bunch of different protections.

I just want to give some feedback about some IPF images which I have write back on different drives here. The KyroFlux seems to do a great job except the PDOS Protection by Rob Northern which was found on different Team 17 products between 1993-94. This protection seems to be very dependent to the drive speed. This was a very known problem for all owners of the Cyclone hardware "T2" which I also own since 1993. Copying this disks without faulty tracks is nearly impossible if you don't have a drive which is more than 0,2-0,3 RPM asynchronous to the source drive. Getting such drives is a real gamble. I didn't have this luck with 3-4 different drives when I try to copy games like "Superfrog, Body Blows Galactic or Arcade Pool", so most drives fail. You can test this with the "speed check" from the Cyclone 12 program from the X-Copy Tool disk...in most cases it display: "No APWM mode with this drives".

Now, almost 20 years later the KryoFlux seems to be face the same problem wich such disks. I used very different drives from Sony, Chinon (FZ-357) and Mitsumi (D359-T3), all with the same result and this is not an issue with the amout of tracks (all drives are working with up to 83 tracks). The curious thing is that the disk is fully working in the drive where is has been written with the KryoFlux adapter, on other drives some random tracks are unreadable. I wrote the same image from "Arcade Pool" on 3 different TDK disks which has been 100% error free tested and formatted, every time the faulty tracks occours on different tracks. So it seems that even the KryoFlux adapter is not able to write this kind of copy protection 1:1 back to disk, all other protections seems to work.

There are some other games which you can try: Jurassic Park, Mortal Kombat I & II, F-17 Challenge. But don't forget to test such disks of different Amiga drives (e.g. from Amiga 500 and A1200) afterwards...you will not be able to get it fully working as this drives are not running at the same speed and KryoFlux is not writing as a real copy station. I don't know wether this can be solved with a firmware of driver update, I just want to point to the fact that this issue is currently a bit to much for the KryoFlux hardware.

That's all from me so far! Thanks for your attention.
User avatar
IFW
Posts: 3080
Joined: Mon Nov 08, 2010 2:42 pm

Re: Not working Amiga Protections

Post by IFW »

KF works exactly like a duplicator machine in fact it has a slightly better resolution than the Trace machines used at the time.
The problem is if your Amiga drive is not running at exactly 300 RPM, as the bitcell width specified is on the verge of what is being (barely) readable by the Amiga FDC - it's a non-issue for KF though.
More over, KF automatically adjusts to your drive speed when writing and constantly monitors it for any changes - unlike the Trace machines.
Please verify that your Amiga drive runs at exactly 300RPM.
Using different type of disks can also help.
User avatar
IFW
Posts: 3080
Joined: Mon Nov 08, 2010 2:42 pm

Re: Not working Amiga Protections

Post by IFW »

Additionally, many of the titles you listed are likely to have serious incompatibility issues in their original copy-protected format when running on different Amiga models, especially A1200, or any accelerators, extra ram, higher than 68000 cpu, cpu caches etc.
Jurassic Park for sure, use the dedicated A1200 version when trying on an A1200 and ensure you try it with a basic a1200 model with no extra hw attached at all. Same about the A500 version, will probably crash with the A1200 one or using any non-standard A500 setup, e.g. 512k chip+512k slow.
PARALAX
Posts: 10
Joined: Sun Mar 25, 2012 8:32 pm

Re: Not working Amiga Protections

Post by PARALAX »

Thanks for letting me know this. I never could find the real reason for this strange behaviour of this protection yet but it was a real challenge every time when I try to copy such disks. So let me explain and add some more informations: I got a drive several months before (Chinon FB-354 = 300,55 RPM) which has been detected as very synchronous to my external drive (Chinon FZ-357 = 300,60 RPM)...that was a lucky deal when I need a new A500 drive for other reasons. I still have some Team 17 originals bought in the 90's like "Superfrog" or "Arcade Pool" which I could examine now again. The fact is that I could copy now this disks 1:1 without problems even with the "Deep Nibble Mode" of Cyclone 12.01 and the T2 hardware. This disks are running on all my 3 Amigas (2x A500, 1x A1200 with 68060 + 64MB Ram) no matter if I turn on the turbo board or not (e.g. "Arcade Pool" detect this card only as 68040 card, thats all). When I try to copy the IPF back with the recommended command "DCT -FFILENAME -W -L15" it works with my first A500 during the first week. 2 weeks later strange loading problems occured on some tracks. When I try to boot the disk from the external drive (I've an A500 boot selector) which I've used to write the IPF back to DD-Disk (I only use high quality DD disks), this problem doesn't occur. But it also occours on my internal A1200 drive even with actually written images on disk with KryoFlux. As this behaviour don't occour with 1:1 copied disk with Cyclone 12.01 and the T2 hardware (with the above said synchronous drives) I have the suspect that the IPF images contains maybe some weak or unstable bits or something which are behaving very different depending from the Amiga drive type...It's just an idea. Or maybe the original disks have been dumped with a bad drive or from an unstable disks at the time (I'm using the original SPS release). Like I said, this protection type is extremely sensitive but I know this behaviour from my older drives I've used in the 90's. It's not a compatibility issue with the Amiga hardware apart from the drive in this case (I even didn't this with "Jurassic Park" as I don't like the game but I know that it use the same kind of protection).

There are many other games with longtrack protected disks like "Pinball Fantasies" or all Turrican games. But this kind of protection did never has a problem with asynchronous drive speeds when I try to copy them 20 years ago, the "PDOS protection" (not the one-track protections) by Rob Northern is the only exception so I think he did a very good job at that time.

I also remember that some PC drives have been modified ex factory for using on Amiga (e.g. for working disk change). I only used old external amiga drives like my external Chinon FZ-357 which I have especially removed from the external drive case to connect with KryoFlux adapter. I'm not sure wether only real PC drives or unmodified drives for using on Amiga should be used with KryoFlux. I can remember that many Mitsumi drives like the D359 series was also used on real PC's. Could that be the reason for the strange behaviour above? Another reason maybe could be the DD disk (I don't use HD disks right now), although all games with the PDOS protection has been sold on DD disks as well.
User avatar
IFW
Posts: 3080
Joined: Mon Nov 08, 2010 2:42 pm

Re: Not working Amiga Protections

Post by IFW »

I took a closer look...
The main reason it fails, is the mark pattern used.
The MFM encoding is limited to 3 consecutive 0 bits.
The mark used by the game is:
1448 4891
(0) 0001 0100 0100 1000 0100 1000 1001 0001

When this pattern is written its readability is questionable - when you copy from disk to disk, the fourth 0 bit when happens is very likely to generate a weak, ie random bit.
The only way to write this pattern to read back as intended properly is to use some magic ;) which would need a fair amount of experimentation to get it right.

Thanks for bringing this to my attention :)
User avatar
IFW
Posts: 3080
Joined: Mon Nov 08, 2010 2:42 pm

Re: Not working Amiga Protections

Post by IFW »

I don't think you can write this properly with any Amiga/DD drive at all... that's the point of doing something like this ;)
Please try with a genuine PC HD drive and a DD disk; I'd recommend the DD enabled Samsung one discussed elsewhere.
[note: not all Samsung drives support DD as the hardware required is not in them, they "just" fail, when you try...]
User avatar
IFW
Posts: 3080
Joined: Mon Nov 08, 2010 2:42 pm

Re: Not working Amiga Protections

Post by IFW »

Please note, that all duplication was done on high quality PC drives at the time, sometimes modified like the ones used for C64 duplication.
There are other protections (using areas that read back on a DD drive as having no flux transitions at all) that are impossible to write or copy on a DD drive - you just haven't encountered those yet, they would fail as well if you attempt to write them with a DD drive.
PARALAX
Posts: 10
Joined: Sun Mar 25, 2012 8:32 pm

Re: Not working Amiga Protections

Post by PARALAX »

IFW wrote:I took a closer look...
The main reason it fails, is the mark pattern used.
The MFM encoding is limited to 3 consecutive 0 bits.
The mark used by the game is:
1448 4891
(0) 0001 0100 0100 1000 0100 1000 1001 0001

When this pattern is written its readability is questionable - when you copy from disk to disk, the fourth 0 bit when happens is very likely to generate a weak, ie random bit.
The only way to write this pattern to read back as intended properly is to use some magic ;) which would need a fair amount of experimentation to get it right.

Thanks for bringing this to my attention :)
It's a pleasure to help when I can do this.:) Unfortunately I have only one PC floppy drive left and this is a SD/Floppy disk combination from TEAC in my Desktop PC. As PC Flöppy disks are more and more unusual in current PC's, the only way would be to buy a special PC drive from eBay or could you recommend the SD/Floppy disk solution from TEAC as well? I remember that there was many reports here that current PC floppy drives are not compatible with KryoFlux at all. As my Floppy drive has been bought in 2006 or 2007, I don't think this could work with KryoFlux. Maybe you have some more information about this.
User avatar
IFW
Posts: 3080
Joined: Mon Nov 08, 2010 2:42 pm

Re: Not working Amiga Protections

Post by IFW »

Probably checking the drive thread or asking around would help to find a suitable HD drive.
We used to have one known good type on the webstore, but it's not available at the moment.
viewtopic.php?f=3&t=4
PARALAX
Posts: 10
Joined: Sun Mar 25, 2012 8:32 pm

Re: Not working Amiga Protections

Post by PARALAX »

What about this drive? It is listed as "fully working" in your list but I don't know wether it has the correct firmware version. Should I buy it for a working copy of the games mentioned above or should I expect the same "gamble effect" like the other drives I've used before?

http://www.ebay.de/itm/Diskettenlaufwer ... 0574352455

Maybe you could try it first if you have one of this drives in your collection, e.g. with "Arcade Pool" and booting on different Amigas.;)
Post Reply