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Gunship problem

Posted: Sat Sep 02, 2017 7:17 pm
by Stefan jL
Has anyone been able to make a copy of Gunship using SCPro and play on a real ST? My dump of gunship do not work if i write it back to disk and the dump does not work in SteemSSE either? The original disk do work on my ST.

Here is my dump of Gunship (from the Megamania compilation)
http://arcade.ym2149.com/files/scpro/gunship_megamania_read2.7z

Re: Gunship problem

Posted: Sun Sep 03, 2017 12:31 am
by dlfrsilver
Please dump as kryoflux stefan :)

Re: Gunship problem

Posted: Sun Sep 03, 2017 7:11 am
by Steven Seagal
Your dump of Gunship is probably good and revealed problems in Steem SSE. :)
First is a plain bug, on track 2, ID over IP, I reset a variable I shouldn't.

Second on track 73 sector 11 is more mysterious.
Is it possible that only 2 special $A1 before a $FE are enough to constitute an address mark? Steem needs 3.
If I say 2 is enough it loads, but maybe it breaks other games.

The MFM of this is:

WD_TYPEII_FIND_ID #0 MFM A224 c $D4 d $02
WD_TYPEII_FIND_ID #1 MFM 6244 c $50 d $8A
WD_TYPEII_FIND_ID #2 MFM 4489 c $0A d $0B
WD_TYPEII_FIND_ID #3 MFM 4489 c $0A d $A1
WD_TYPEII_FIND_ID #4 MFM 5554 c $00 d $FE

Re: Gunship problem

Posted: Sun Sep 03, 2017 8:15 am
by Steven Seagal
There was already an SCP dump of Gunship that works in v3.9.2.
IP happens at a different place.

The MFM for sector 73/11 is:

WD_TYPEII_FIND_ID #5572 MFM A224 c $D4 d $02
WD_TYPEII_FIND_ID #5573 MFM 4489 c $0A d $0B
WD_TYPEII_FIND_ID #5574 MFM 4489 c $0A d $A1
WD_TYPEII_FIND_ID #5575 MFM 4489 c $0A d $A1
WD_TYPEII_FIND_ID #5576 MFM 5554 c $00 d $FE

Re: Gunship problem

Posted: Sun Sep 03, 2017 11:46 am
by Maartau
Steven Seagal wrote:There was already an SCP dump of Gunship that works in v3.9.2.


Steven, is the other SCP coming from "Air Sea Supremacy" (compilation) ?

http://www.atarimania.com/game-atari-st ... 24298.html

Re: Gunship problem

Posted: Sun Sep 03, 2017 3:09 pm
by ijor
Stefan jL wrote:Has anyone been able to make a copy of Gunship using SCPro and play on a real ST? My dump of gunship do not work if i write it back to disk and the dump does not work in SteemSSE either? The original disk do work on my ST.


Your dump seems to be good. At least it loads up to the screen that you are asked to identify the tank.

This disk has data under the index. That means that the tracks were not formatted aligned to the disk index. You might need to set the correct parameters with the SCPro software. Even then, there might be a bug in the SCP software that is not identifying the write splice correctly, especially in the copy protected track.

I am afraid that I am not very familiar with the SCP software, but I might get an idea about the problem if you make a dump of the non working copy.

Btw, there are plenty of different versions of Gunship.

Re: Gunship problem

Posted: Sun Sep 03, 2017 3:18 pm
by ijor
Steven Seagal wrote:Second on track 73 sector 11 is more mysterious.
Is it possible that only 2 special $A1 before a $FE are enough to constitute an address mark? Steem needs 3.
If I say 2 is enough it loads, but maybe it breaks other games.


No, 2 syncs only are not valid. But that seems a bug in your decoder, I see 3 syncs there. Note that in this case the syncs are right at the start of the track.

There was already an SCP dump of Gunship that works in v3.9.2.IP happens at a different place.


As I said above, there are many different versions of Gunship. And for each version, the index alignment is not constant. If that dump is this same version (no idea, didn't check) and it does work for you, then I'd say that you probably have a bug when decoding syncs right at the start.

Re: Gunship problem

Posted: Sun Sep 03, 2017 3:35 pm
by dlfrsilver
This release of gunship use a speedlock. I have yet to determine which version, but the game loads here correctly in CTraw format.

Re: Gunship problem

Posted: Sun Sep 03, 2017 6:25 pm
by Steven Seagal
Maartau wrote:Steven, is the other SCP coming from "Air Sea Supremacy" (compilation) ?

http://www.atarimania.com/game-atari-st ... 24298.html


Probably as the file has 'ASS' in it. Could be confusing. :mrgreen:

ijor wrote:No, 2 syncs only are not valid. But that seems a bug in your decoder, I see 3 syncs there. Note that in this case the syncs are right at the start of the track.


Thx for looking into it. The decoder is mainly 3rd party so it's not buggy. ;)
The real bug is loading first rev again while the AM detector is on... it was a bad idea.
Now that dump loads.

Another question: is 4 $A1 + $FE valid as address mark?

Re: Gunship problem

Posted: Sat Sep 09, 2017 4:19 pm
by Stefan jL
Did a search in the forum about Gunship and found out DrCoolZic says that Gunship can't written back to disk.

DrCoolZic wrote:Here we have a different aproach: the inner gap is maintained at 34 bytes but the gap between sector is reduced to 2. So reading will work without problem but writing will probably result in overwriting next sector (i.e. read-only)

http://www.atari-forum.com/viewtopic.php?f=1&t=25586&p=265587&hilit=gunship#p265587

Thats the version that is part of the Megamania compilation.

Re: Gunship problem

Posted: Sat Sep 09, 2017 6:37 pm
by ijor
Stefan jL wrote:Did a search in the forum about Gunship and found out DrCoolZic says that Gunship can't written back to disk.


No. You are misinterpreting what he is saying and that's not the problem you are facing. Some versions of Gunship have a problem if you write an individual sector, such as when writing the high score. This might result in damaging the next sector. This has nothing to do with writing back the whole disk using low level hardware such as the SCP. As long as the hardware write the whole track in one single pass it shouldn't be a problem.

Again, read my initial reply to your post. I explained the (most likely) reason your write back is failing. And as I said there, if you want to be sure then dump the non working copy and I could check it to be sure.

Re: Gunship problem

Posted: Sun Sep 10, 2017 1:30 pm
by Stefan jL
Oops... yes i misunderstod DrCoolZic.
Now i have made an copy of the scpro copy i wrote back to a disk:
http://arcade.ym2149.com/files/scpro/gunship_megamania_scpro_copy.7z

Re: Gunship problem

Posted: Mon Sep 11, 2017 3:23 am
by ijor
Definitely a problem with sectors under the index. I can't say for sure if you are using the wrong parameters or it's a bug in the SCP software.

As I said, I don't own a SCP and I am not very familiar with it. But try changing the "Copy Mode' when writing back. This should be required for disks, such as this one, that have data under the index. But this can sometimes might be tricky for the software, and I don't know how good the SCP software handles this. So conceivable won't work.

Re: Gunship problem

Posted: Sat Sep 16, 2017 11:21 am
by Stefan jL
Thanks for your reply ijor, i am using the "splice" mode.
Maybe a bad diskdrive or something i don't know. Is there anybody here that can test the Gunship SCP dump and write it back to disk and see if it works for you on a real ST?

Re: Gunship problem

Posted: Sun Sep 17, 2017 1:24 am
by ijor
I don't think it is a problem of the drive. I suspect it is a problem of the SCPro software that is not detecting the write splice correctly. May be worth to check with Jim. Just in case, are you using the latest SCPro software/firmware?

Re: Gunship problem

Posted: Sun Sep 17, 2017 7:52 am
by kodak80
Stefan jL wrote:Thanks for your reply ijor, i am using the "splice" mode.
Maybe a bad diskdrive or something i don't know. Is there anybody here that can test the Gunship SCP dump and write it back to disk and see if it works for you on a real ST?

I have tried writing back your SCP dump to disk with my SCP board and no luck with the disk it creates. I have tried both splice and index modes with weak bit setting in both states as well as changing the index sensor to ingnore and required. Changing the settings for writing in the SCP software has no effect and the disk created does not work.

I would raise this on the SCP forum and see if Jim can answer why it does not work?

Re: Gunship problem

Posted: Tue Sep 19, 2017 4:20 pm
by Stefan jL
kodak80 did you use the file i posted in the first post? Just have to ask so i can be sure you did not mix it up with the later copy of a copy dump i posted later :)
I have removed the copy of a copy dump now.

Re: Gunship problem

Posted: Mon Sep 25, 2017 5:36 pm
by JimDrew
I just saw this post. Where is the image file? I would like to look at it to determine the problem. Sounds like the SPLICE routine is not finding the write splice and is writing two revolutions back.

Re: Gunship problem

Posted: Mon Sep 25, 2017 5:46 pm
by Stefan jL
The image is in the first post... the download did not work as the server was down but it works again now.

Re: Gunship problem

Posted: Mon Sep 25, 2017 8:23 pm
by kodak80
Stefan jL wrote:kodak80 did you use the file i posted in the first post? Just have to ask so i can be sure you did not mix it up with the later copy of a copy dump i posted later :)
I have removed the copy of a copy dump now.

Yes, I used your original dump file.