Farb

Here are the titles we have flagged as containing artifacting in the preservation database: http://www.a8preservation.com/#/software?f=t:ARTF&page=1 I see a few that aren't on your list including some Crystalware adventures and the Sierra Hi-Res Adventure series.

Thank you for sharing these, @Zarxx!

Interestingly, the torrent CAS works fine on real hardware (checked by @Fred_M converting the CAS to WAV and recording to a real cassette) and on the Atari800 emulator. So it seems like we're looking at an Altirra-specific issue. @Atarigrub has identified some differences in the baud rate and gap between data blocks across the different dumps which seem to account for the differences in behavior between our CAS and Zarxx's. We are still trying to determine what would make for the most accurate CAS file.

Yes, it has been preserved... Disk File Manager v1.0 (1979-09-24)(Atari)(US)[disk].zip

Thanks, @Zarxx. We'll take a look and see how it differs from the current dump in the torrent. And thanks for the interesting information @Shannon. Any chance you remember where you learned this from?

Well, it depends what you mean by "easy" 🙂 The PRO file format does not contain all the necessary information to properly represent a disk. The ATX file format, on the other hand, does contain that information. So, to convert a PRO to an ATX, the missing information has to be created by making educated guesses about what the original disk layout looked like. Sometimes theses guesses are easy to make and sometimes they are close to impossible. Version 0.5.0 of my a8diskutil utility (among other things) has a convert function that can read a PRO file and create an ATX. You run it via: a8diskutil convert foo.pro foo.atx (Mac / Linux) a8diskutil.exe convert foo.pro foo.atx (Windows) So it is easy to convert PRO files using this utility but the resulting ATX may not work reliably for disks that had more advanced protection. a8diskutil makes a best effort to create a working ATX but there's only so much it can do. Keep that in mind while playing with it. Here is the latest version for different platforms (Mac version is the first link): http://www.a8preservation.com/downloads/a8diskutil-darwin-amd64-0.5.0.zip http://www.a8preservation.com/downloads/a8diskutil-win-amd64-0.5.0.zip http://www.a8preservation.com/downloads/a8diskutil-win-i386-0.5.0.zip http://www.a8preservation.com/downloads/a8diskutil-linux-amd64-0.5.0.zip

I've tried to document the different known variants here: http://www.a8preservation.com/#/software/title/17 See the descriptions of each release for more info.

These are great, @Dutchman2000! Thank you very much for sharing.

Hi all, it long overdue for a new preservation torrent. If anyone is interested in creating and seeding one for us, please PM me. Thanks!

Thanks for the ATX files. Caverns of Mars isn't protected but also doesn't match any dump we have - the sector interleave is different. I am uncertain if this is a legitimate variant or a side effect of the way it was dumped. Choplifter also doesn't match any verified dump we have. The closest match is to our [a] dump but it has data differences in the first two sectors and the interleave of the protection track is different. I'm also not sure here what the cause of the difference might be.

@toddtmw beat me to it. I'd give both sides of Top Gunner Collection a shot since it's already preserved, would test missing sectors, duplicate sectors and whether skew alignment is replicated correctly.

You can certainly try that. Ultima disks are a very trivial example I would expect to work fine since they only leverage simple missing sectors. Just be aware that these old disks will vary in what kind of shape they are in and how many reads they will be able to tolerate before they begin suffering permanent data loss. So it is possible that a test boot or a test dump is the only completely good read you get. I've heard folks in the past disagree with that statement, but I've personally dumped and processed well over 1000 disks and have seen this phenomenon first hand. Update: If you try to dump them yourself, be sure to check the drive head in between each dump to check if debris has accumulated. If so, clean the head before the next dump. The build-up of head debris can easily prevent a good dump and possibly destroy the disk.

@djmat56, it's great to hear from you! I hope you are doing well. Yes, many of the tape images in our archive are yours. Fortunately, we've been able to verify many of them over the past few years with contributions from others 🙂 Thank you for putting the list together. And thanks @toddtmw for cross-referencing the list with the preservation database 👍 As @toddtmw indicated, we often have a better chance of preserving disks if we can do a flux dump with Kryoflux or SuperCard Pro. If you would be willing to send them to me in Germany, I can dump them and return them to you. However, I understand if you don't want to incur risk or cost to send disks, so we'll take dumps made on an Atari drive as a last resort. I honestly don't know the quality of an ATX that Respeqt generates as I don't even own an Atari drive anymore 😛 There will be titles that simply can't be dumped accurately using such a method (not sure if any of yours fall in that category though).

Thanks for pointing out the problems you found. A number had already been corrected in the database and I've fixed the others that I am able to. As @ijor said, some of them are ATX files that were made a long time ago. $74 is the creator for my a8diskutils.

I recall Archon having this behavior as well. I didn't think the floating bus had anything to do with the EA protection but I could be wrong. I know one title whose protection was affected by the A800's floating bus was Coleco's WarGames. I had contacted phaeron about it because the verified ATX worked on a real Atari but not Altirra. As I recall, the floating bus emulation was pretty CPU intensive so was off by default.