Snakes!

[prowler]

Okay, I've exhausted my collection of previous images of this disk without fixing any more bad sectors, but I got it running in A500 WinUAE configuration nonetheless.

The developer's name, previously known only as "Slash", is revealed as Peter Feenstra in the opening credits!

When the opening screen arrives, it is garbled (screenshot attached). I am not sure whether this is due to my DirectX settings or disk corruption. The music plays okay, and Level 1 starts up when the spacebar is pressed.

As promised, I attach the WIP1 disk image for testing. All comments and attempts at fixing any problems will be welcome.

Originally Posted by flateric

Thanks for the update and great work Prowler. Where did you learn all this?

I had to learn how to salvage corrupted disks when faced with the need to do it. I started by reading all documentation bundled with disk recovery software and related utilities on Aminet, tried the programs and found alternative ways of succeeding where they failed - first by reading books on Amiga disks and drives, then by instinct, trial and error, blood, sweat and tears, and finally with success and smiles.

[prowler]

I fixed another three bad sectors this evening, so now there are only 16 to go...

I attach the WIP2 disk image for anyone who is testing it.

If the garbled opening screen I get with the WIP1 version is found to be due to disk corruption, then WIP2 probably will not fix it as the changes are only trivial (and I have not tested it myself yet).

[Retro1234]

Thank you

Bravo Prowler! I get the garbled intro page as well, but the first few levels seem fine. When I have time I will try all 50 levels - bearing in mind I only had the demo before The Amiga version is so much better than the PC version. Prowler, maybe you should look at a career in digital forensics

[Paul_s]

I do often wonder if Prowler is secretly MacGuyver?

[prowler]

Originally Posted by flateric

Bravo Prowler! I get the garbled intro page as well, but the first few levels seem fine. When I have time I will try all 50 levels - bearing in mind I only had the demo before The Amiga version is so much better than the PC version. Prowler, maybe you should look at a career in digital forensics

Thanks for your feedback, flateric! I really appreciate it.

If you can reproduce the garbled screen, then the cause is not my DirectX settings but disk corruption. Unfortunately, the one sector on the disk which may be unrecoverable is the likely culprit. If it is, it may be possible to reconstruct it with code from the demo version.

It's good to know that the early levels are intact. This evening I have fixed another four bad sectors, leaving just twelve, and this will help if you are going to try all 50 levels.

@Boo Boo: If you're testing this disk image as well, please let me know how it's going. Any information you can provide, however trivial it might seem, will help me fix the sectors I have not so far managed to salvage intact from the disk.

The WIP3 disk image is attached for all those who are interested.

[Retro1234]

Dont know if this info is of any use but I used Track2File with Snakes-WIP2 and the actual Picture file seems to be intact - i.e the picture open correctly in GfxRip.

[clenched]

Prowler - real savvy in restoring this game. This game has a built-in level skip that can vastly speed up checking that all the levels look OK. Start at opening screen where options are set up. Make sure only one orange ball (left of keyboard) shows. Keep pressing CTRL until screen flashes green. Now at minimum you have unlimited lives and levels can be skipped with Help key. Who knows what else?

[prowler]

Originally Posted by Boo Boo

Dont know if this info is of any use but I used Track2File with Snakes-WIP2 and the actual Picture file seems to be intact - i.e the picture open correctly in GfxRip.

Thanks, Boo Boo!

Your report confirms that the missing sector has nothing to do with the screen corruption and that will make it easier to fix, as most of the other bad sectors require only minimal edits (one or two bits) to repair them.

Would it be possible for you to upload the actual picture for me to use as a reference while making adjustments to the disk image? That would be a great help if it's not too much trouble for you.

Originally Posted by clenched

Prowler - real savvy in restoring this game. This game has a built-in level skip that can vastly speed up checking that all the levels look OK. Start at opening screen where options are set up. Make sure only one orange ball (left of keyboard) shows. Keep pressing CTRL until screen flashes green. Now at minimum you have unlimited lives and levels can be skipped with Help key. Who knows what else?

Thanks for that, clenched!

I was wondering if there was a level skip option. It will make debugging level corruption much less tedious.

This evening, I have fixed another bad sector to leave just eleven remaining, and I attach the WIP4 disk image here.

[Retro1234]

I put the file in the Zone I think the file is between !277,578 to !291,765 on the ADF


I dont know but guess its possible that the picture(Tile Screen) could be on the disk twice? One corrupt one not.

[prowler]

Originally Posted by Boo Boo

I put the file in the Zone I think the file is between !277,578 to !291,765 on the ADF

Thanks, Boo Boo!

Originally Posted by Boo Boo

I dont know but guess its possible that the picture(Tile Screen) could be on the disk twice? One corrupt one not.

I don't think think that's likely, but I'll bear it in mind.

Edit: I've played around with SNAKES1.RAW in GfxRip, but so far I've not been able to display the picture properly. Could you please either tell me what keypresses are required to do that, or upload a screen capture of it? Thanks.

[Retro1234]

Originally Posted by prowler

Edit: I've played around with SNAKES1.RAW in GfxRip, but so far I've not been able to display the picture properly. Could you please either tell me what keypresses are required to do that, or upload a screen capture of it? Thanks.

Use xfdDecrunch to unpack it, anything could be used to view it, like ArtPro I used DeluxeGfxRipper
320*256 5 BitPlanes ST/RAW Interleaved
Theres also a highscore Table picture but that displays correctly.

[prowler]

Originally Posted by Boo Boo

Use xfdDecrunch to unpack it, anything could be used to view it, like ArtPro I used DeluxeGfxRipper
320*256 5 BitPlanes ST/RAW Interleaved

Thanks, Boo Boo. That's a great help!

I had noticed that the first four bytes of SNAKES1.RAW are 'PP20' and I wondered if the reason it wouldn't display properly was that it's PowerPacked.

Originally Posted by Boo Boo

Theres also a highscore Table picture but that displays correctly.

Fortunately, that picture displays properly even when the game is played using the WIP1 disk image.

[Retro1234]

Yep I probably shouldnt have named it .RAW - Hope you have some luck if not well done so far

[prowler]

Originally Posted by Boo Boo

Yep I probably shouldnt have named it .RAW - Hope you have some luck if not well done so far

I'm not done trying to salvage it yet. I have a few more disk drives I would like to try it with first, and then further fixes will be done with a binary file editor in response to bug reports and my own attempts to play the game in emulation.

It would be useful if somebody could upload a disk image with one or more highscores added... Please?

[clenched]

There is a bug on level 15 (wip-4). Don't touch the controls and just let the snake take off due east on its own. When it hits the blue mine the game just locks up. This happens on real A500 and WinUAE. I notice this level doesn't have the tile symmetry of prior levels but since no garbage shows it looks OK at a glance. Hitting other mines the game goes as expected and as long as that particular blue mine is avoided the level can be completed normally. All this makes me suspect levels 1 and 2 since they look like two dark voids compared to the other levels.

[prowler]

Originally Posted by clenched

There is a bug on level 15 (wip-4). Don't touch the controls and just let the snake take off due east on its own. When it hits the blue mine the game just locks up. This happens on real A500 and WinUAE. I notice this level doesn't have the tile symmetry of prior levels but since no garbage shows it looks OK at a glance. Hitting other mines the game goes as expected and as long as that particular blue mine is avoided the level can be completed normally. All this makes me suspect levels 1 and 2 since they look like two dark voids compared to the other levels.

Hi clenched, thanks for your bug report concerning Level 15.

I'm not at the stage where I'm looking for bugfixes yet, because I want to exhaust every possibility of salvaging data from the disk first, and that won't be for another couple of weeks or more. Then, my first priority will be to fix the intro screen loading.

It does sound as if you've found a bug due to disk corruption, as most of the fixes have involved very minor changes indeed.

I realize that the first two levels seem very spartan compared to the others and those of the demo version, but maybe that is done deliberately to provide a couple of beginner levels for those who are attempting to play the full version without having played the demo first, and there are fifty levels in total, after all. So, I'll only be looking for problems with those if bugs are actually reported.

Originally Posted by Boo Boo

I put the file in the Zone I think the file is between !277,578 to !291,765 on the ADF

I dont know but guess its possible that the picture(Tile Screen) could be on the disk twice? One corrupt one not.

Hi Boo Boo,

As you have found, the SNAKES1.RAW data is at offset 277,578 (0x43C4A) to 291,765 (0x473B5) inclusive in the snakes.adf file. However, no part of this picture is on the disk twice, unless the other uses a different compression method or is uncompressed.

Originally Posted by Boo Boo

Theres also a highscore Table picture but that displays correctly.

Could you upload the raw data for the highscore table for me please, or tell me the range of offsets where it can be found in the ADF? Thanks.

@Thread: I've not had any success saving highscores to the disk. Are they really lost each time you quit the game, or is there something I'm missing?

Over the weekend, I have fixed another bad sector, leaving just 10. I attach the WIP5 disk image here, and I would recommend using this new version if you are testing the game in case it fixes anything.

As you will see, the opening screen is still not fixed. Unfortunately, all except one of the remaining bad sectors occur in the tracks which are accessed while the screen is loading.

BTW, I have replaced the screen capture in my WIP1 post above, because the original speed indication box was corrupted by my pressing the ALT key to capture just the active window rather than the screen!

[prowler]

This evening I have achieved a minor miracle and salvaged the bad sector that I had thought was going to be unrecoverable!

The WIP6 disk image has only nine bad sectors, and there is a realistic chance that they can all be fixed!

[whitegiant89]

just had a quikie at wip6, title screen is still scrambled, did not go past first level, but has sound and music playing ok

[prowler]

Originally Posted by whitegiant89

just had a quikie at wip6, title screen is still scrambled, did not go past first level, but has sound and music playing ok

Thanks for having a look, whitegiant89.

I should receive another A1200 in the next couple of days, and that will enable me to conclude my efforts to salvage what I can from the disk. Then I'll have a go at fixing that annoying title screen corruption.