Atari 800 "Impossible" disk backup board

[Chuck Gill]

I have an 800 with "The Impossible" disk backup system installed in it. The board is a custom OS board that allows you to duplicate a copy protected disk on an unmodified disk drive. The only catch is that the disk will only play on a computer with an impossible board installed.

 

I lost all my Antic and Analog magazines a few years ago and I would appreciate it if someone could scan an image of an advertisement for The Impossible. I remember seeing them frequently in the magazine ads back in the day.

 

-Chuck

[sloopy]

O.O

 

sloopy.

[Nukey Shay]

I guess it's about 3 decades too late to yell "shenanigans" and smack them with broom handles?

 

It says that the protection is removed and copies run on any machine

[ijor]

It says that the protection is removed and copies run on any machine

 

I don't think it claims that, does it? What it claims is that it works on any disk drive (not any machine). The idea is that you can back up (sort of ...) copy protected disk using a stock 1050 or 810, that's why they called it "impossible".

 

However, IMHO, the whole thing is still misleading. The hardware doesn't really copy any disk at all. The hardware it's actually a freezer with save/restore capability.

 

Later CSS released a software only product that could run some of those backups made with the impossible. I believe it was called "XL Mate", but I'm not 100% sure.

[Rybags]

It's partially true.

 

For games that load then don't have further disk access and will resume if you press RESET, a simple RAM dump/restore will be sufficient to make a copy.

 

Even for games that do disk access, that technique will work as long as subsequent disk I/O doesn't rely on the bad sectors being present.

 

I see this version has a 4K static RAM - so in all likelihood is maps to $C000, which would allow the program to preserve the entire 48K RAM contents rather than the overwriting that would occur when dumping to disk.

 

Also, assuming it does have a custom OS ROM, it could use a different NMI System Reset routine that doesn't wipe parts of low RAM if the user's requested a dump.

If done right, it could even create a copy that restored the game to the exact state it was in, e.g. in the middle of a game level.

 

But the problem with a "Restore State" on the real hardware is that since most of the HW Registers you need to restore are Write-only, you have to rely on the actual game to refresh the proper values for you.

[Nukey Shay]

Nevermind.

 

Writing something in a "totally unprotected format" doesn't really mean anything at all. Dos is a totally unprotected format

[Bryan]

I see this version has a 4K static RAM - so in all likelihood is maps to $C000, which would allow the program to preserve the entire 48K RAM contents rather than the overwriting that would occur when dumping to disk.

 

That reminds me... When I disassembled MULE, I found it looking for something at $C000 to jump to.

[Rybags]

Maybe part of it's copy-protection, crash and burn if it's not there.

Or maybe just a self-modified instruction that's changed later.

 

Or maybe some sort of residual code from a test version that does a Monitor call.

[Chuck Gill]

O.O

 

sloopy.

Sloopy, thanks! Exactly what I was looking for.

 

-Chuck

[Nukey Shay]

IIRC I've got the commercial game's sector edits to remove M.U.L.E.'s c/p laying around here someplace...probably points right at it.

 

Or are you referring to a "The Impossible" backup file?

[Chuck Gill]

It does write the backups in an unprotected format, you can copy them with a sector copier. They still won't run without the Impossible board. The Impossible does plug into the socket that the OS chip was in. Of course all markings on the chips were removed to make it harder to reverse engineer.

 

All the Electronic Arts games stop and say "Remove rom at $C000" if they found anything there. That's what they do on my 130XE with a custom OS.

 

-Chuck

[ijor]

Or maybe some sort of residual code from a test version that does a Monitor call.

 

It surely is:

 

311E			LDA RANDOM
3121			STA $C000
3124			CMP $C000
3127			BEQ $312A
3129	      	        RTS 
312A	     	        LDA $C001
312D			CMP #$4C	; JMP
312F			BNE $3129
3131			JMP $C001

[fibrewire]

I guess I just bought one of these... Stay tuned!

[Mathy]

Hello guys

 

Software protection works, because the software expects a certain behavior. Protected software checks for certain things, like bad sectors, fuzzy sectors, etc. What the Impossible does, is check what the software protection expects and recreates/emulates this. For instance, if the software expects a fuzzy sector, the Impossible makes the software think, there is a fuzzy sector. That's why it would probably even work on SD devices, that can't have fuzzy sectors.

 

The Impossible was called Impossible because people said it was impossible to fool protected software that way.

 

CU

 

Mathy

[Rybags]

The important thing would be just intercepting the SIOV call. And you'd need a list of what sectors need special actions performed, which would need to be stored in some bit of RAM seperate from main RAM (maybe switch out FP package ? )

You'd have to wonder how sophisticated it is though... it's all well and good "emulating" stuff like duplicate/missing/fuzzy sectors but more sophisticated detection techniques that relied on timing thresholds might not have been emulated well.

 

"The Impossible" that I remember, I think I got a copy somewhere, was the earlier one that just dumped out the RAM contents. It relied on the game not coldstarting if the user hit Reset, and not modifying the CASINI vector.

[AtariGeezer]

I guess I just bought one of these... Stay tuned!

 

I'd be interested in seeing if this has one or two 6264 ram chips. I've seen a pic of the one board that has two, but mine only has one...

 

Jay

[gtmtnbiker]

When I was a teenager with an Atari 800 and Percom high density floppy drive, I had one of these "Impossible" devices. Does anyone have any photos of it? For the life of me, I can't remember what it looked like.

[fibrewire]

krap - I forgot all about this one. He probably sold it by now... I couldn't pay via PayPal, which meant a special trip to the post office.

[Atariman56]

krap - I forgot all about this one. He probably sold it by now... I couldn't pay via PayPal, which meant a special trip to the post office.

 

I emailed you about a week or 2 ago asking if you still wanted the Impossible that you had asked me to hold for you.I still have 2 left. Will you make good on your request? Hmmmmmm.....

Edited September 16, 2011 by Atariman56

[fibrewire]

Absolutely!

[Atariman56]

Absolutely!

 

 

Interesting, you replied to me right away after I mentioned that I've been holding the impossible for you for 3 weeks. However it is now 9 days later since your reply above and you still have not contacted me about making good on your request. Hmmmmmmm still again