VOGONS


First post, by red_avatar

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I have a bit of a problem. I started a project to rip all my Windows 9X and Windows XP games to CD images to save my CD/DVD drives from degrading too much. This seemed to work amazingly at first glance - Alcohol 120% defeats almost every copy protection - but I discovered that the CD images are not always reliable. A game would throw errors during installation or would crash due to corrupted files and this seems to stem from the CD image not being a perfect rip. Normally this is not a problem but to defeat copy protection, you HAVE to enable "ignore errors" and I believe this is where the problem stems from since it will not try multiple reads of a bad sector meaning I have CD images with data missing.

Anyway, after a lot of searching and thinking I realized this is simple impossible to avoid. Usually attempting a second CD rip fixes the problem but I'm never sure there isn't a new error in another area of the CD.

That made me think: the easiest solution here would be for some software to compare files of the CD image with the files on the CD itself byte per byte and check for differences.

The question is now: what tool would be ideal to use for this? Ideally it would be run in Windows 98 but since I store all images on USB sticks I could technically do it on a modern PC but that would mean using my external DVD drive (and I prefer not to use it too much since the new ones you can get are trash). Would a file checksum tool be suitable or reliable for this job?

Retro game fanatic.
IBM PS1 386SX25 - 4MB
IBM Aptiva 486SX33 - 8MB - 2GB CF - SB16
IBM PC350 P233MMX - 64MB - 32GB SSD - AWE64 - Voodoo2
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i5-2500k - 3GB - SB Audigy 2 - HD 4870

Reply 2 of 13, by rasteri

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You'd have to rip the CD at least 3 times, then and pick the version of each file that appears in at least 2 of the 3 images.

I'm not aware of any tool that automates this, although it wouldn't be too hard to knock something up if you can script

Reply 3 of 13, by Deksor

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I second rasteri. Dump your CDs twice and check if the cheksum is the same. If it's not, dump it again and check if any of your images now match.

If it still doesn't, inspect the CD, clean it and try again. Otherwise your CD might be just dead.

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 4 of 13, by red_avatar

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Azarien wrote on 2022-06-10, 15:37:

Total Commander and its "synchronize dirs" feature?
Or any other folder synchronization tool.

I'll try Total Commander - see if it does what I need to do with ease. It's supposed to compare subfolders etc. as well so not sure if this will work. Most sync tools also don't work on Windows 98 AND they generally don't do what I need to but just look at file date & size.

Retro game fanatic.
IBM PS1 386SX25 - 4MB
IBM Aptiva 486SX33 - 8MB - 2GB CF - SB16
IBM PC350 P233MMX - 64MB - 32GB SSD - AWE64 - Voodoo2
PIII600 - 320MB - 480GB SSD - SB Live! - GF4 Ti 4200
i5-2500k - 3GB - SB Audigy 2 - HD 4870

Reply 5 of 13, by red_avatar

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Deksor wrote on 2022-06-10, 16:29:

I second rasteri. Dump your CDs twice and check if the cheksum is the same. If it's not, dump it again and check if any of your images now match.

If it still doesn't, inspect the CD, clean it and try again. Otherwise your CD might be just dead.

That's not very healthy for the laser though. Even ripping once is already a lot of work - some CDs take over an hour and decent CD/DVD drives are hard to come by these days. I have a pile of them that don't properly work anymore as is ...

But isn't my way better: compare the checksum of the CD in the drive with the checksum of the CD image? If it encounters a reading error on the CD, I know the CD needs cleaning at least and if it doesn't, both checksums should be identical.

Retro game fanatic.
IBM PS1 386SX25 - 4MB
IBM Aptiva 486SX33 - 8MB - 2GB CF - SB16
IBM PC350 P233MMX - 64MB - 32GB SSD - AWE64 - Voodoo2
PIII600 - 320MB - 480GB SSD - SB Live! - GF4 Ti 4200
i5-2500k - 3GB - SB Audigy 2 - HD 4870

Reply 6 of 13, by Deksor

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It depends. Copy protected files with fake bad sectors might report a bad checksum even if they're actually fine

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 7 of 13, by red_avatar

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Deksor wrote on 2022-06-10, 17:15:

It depends. Copy protected files with fake bad sectors might report a bad checksum even if they're actually fine

Well that one is easy: if it installs fine & runs fine, then the copy protected files won't be an issue. Alcohol actually has built-in copy protection emulation so you have some leeway here. Having actual game files being corrupted - now that I won't accept. Since this is for Windows 98, I don't have to worry about crap like Starfarce which is a horrible HORRIBLE copy protection that killed more than a few of my drives back then.

Retro game fanatic.
IBM PS1 386SX25 - 4MB
IBM Aptiva 486SX33 - 8MB - 2GB CF - SB16
IBM PC350 P233MMX - 64MB - 32GB SSD - AWE64 - Voodoo2
PIII600 - 320MB - 480GB SSD - SB Live! - GF4 Ti 4200
i5-2500k - 3GB - SB Audigy 2 - HD 4870

Reply 8 of 13, by rasteri

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red_avatar wrote on 2022-06-10, 16:53:

But isn't my way better: compare the checksum of the CD in the drive with the checksum of the CD image? If it encounters a reading error on the CD, I know the CD needs cleaning at least and if it doesn't, both checksums should be identical.

Once you have read the image, how can you know what the checksum of the CD is without reading it at least once more?

Reply 9 of 13, by red_avatar

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rasteri wrote on 2022-06-10, 18:16:
red_avatar wrote on 2022-06-10, 16:53:

But isn't my way better: compare the checksum of the CD in the drive with the checksum of the CD image? If it encounters a reading error on the CD, I know the CD needs cleaning at least and if it doesn't, both checksums should be identical.

Once you have read the image, how can you know what the checksum of the CD is without reading it at least once more?

I guess I improperly used the term "checksum". I used Azarien's suggestion and tried Total Commander and it works really well. It told me exactly which files did not match. I'm now trying to find a way to edit MDF files in such a way that the files are still readable by Alcohol 120% and still defeat the copy protection. At worst I will know if an image is good or not which is more than I knew before. Also, stupid me didn't turn down the speed of the CD drive when ripping the CD - I dropped it from 40 to 8Mbps.

Retro game fanatic.
IBM PS1 386SX25 - 4MB
IBM Aptiva 486SX33 - 8MB - 2GB CF - SB16
IBM PC350 P233MMX - 64MB - 32GB SSD - AWE64 - Voodoo2
PIII600 - 320MB - 480GB SSD - SB Live! - GF4 Ti 4200
i5-2500k - 3GB - SB Audigy 2 - HD 4870

Reply 10 of 13, by pentiumspeed

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Get LG optical drives. Their laser is very reliable. Philips chassis (many brands use these back in the day), had very short laser life.

Cheers,

Great Northern aka Canada.

Reply 11 of 13, by red_avatar

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pentiumspeed wrote on 2022-06-10, 22:42:

Get LG optical drives. Their laser is very reliable. Philips chassis (many brands use these back in the day), had very short laser life.

Cheers,

I have all kinds of brands including LG - the main problem I have isn't the laser but the motors. Either the motor that spins the disc or the tiny motor that makes the laser move up and down or the motor that opens & closes the tray.

On the plus side, Total Commander works awesome - it gives me certainty that games won't have corrupted files. I'm now going through all my ripped images (some 40 so quite a lot already) and verifying them. So far Z Steel Soldiers is the only one that gave me problems (Securom 2) but there's a CD Copy crack for it anyway.

It's a fun thing to keep me busy - I have some 3000 PC games and most are on CD so it makes sense to make usable backups. DOS CD games are easy - even ISO files are sufficient if there's no CD audio - and I already use mainly CD copies to save the original CDs from wear & tear. Windows 98 games so far are relatively easy as well. I fear once I hit the XP years, things will become less fun ... .

Retro game fanatic.
IBM PS1 386SX25 - 4MB
IBM Aptiva 486SX33 - 8MB - 2GB CF - SB16
IBM PC350 P233MMX - 64MB - 32GB SSD - AWE64 - Voodoo2
PIII600 - 320MB - 480GB SSD - SB Live! - GF4 Ti 4200
i5-2500k - 3GB - SB Audigy 2 - HD 4870

Reply 12 of 13, by Horun

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Another suggestion is to burn at the lowest speed possible. I have done that forever and have old CDR from before 1999 that still read like I just did them after many years and many reads.. but you probably already figured that out ;p

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. https://archive.org/details/@horun

Reply 13 of 13, by red_avatar

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Horun wrote on 2022-06-11, 03:25:

Another suggestion is to burn at the lowest speed possible. I have done that forever and have old CDR from before 1999 that still read like I just did them after many years and many reads.. but you probably already figured that out ;p

I actually don't burn CDs except for DOS. For DOS there's currently no other solution sadly enough - I was hoping some CD emulation device would exist by now but it doesn't.

Retro game fanatic.
IBM PS1 386SX25 - 4MB
IBM Aptiva 486SX33 - 8MB - 2GB CF - SB16
IBM PC350 P233MMX - 64MB - 32GB SSD - AWE64 - Voodoo2
PIII600 - 320MB - 480GB SSD - SB Live! - GF4 Ti 4200
i5-2500k - 3GB - SB Audigy 2 - HD 4870