by Brian Moriarty

This article is not another sermon on the evils of disk pirating. Anybody with two cents' worth of intelligence knows that pirating is wrong, and that unauthorized software duplication violates the author's right to a fair profit.

But what are the rights of a software BUYER? Is it legal for the original purchaser of a disk to make personal copies? Is it possible to duplicate a "copy-protected" disk? Is it moral to sell a disk copying program - or to advertise one?

This last question is of particular concern to the staff here at A.N.A.L.O.G. Over a dozen ATARI disk copiers have appeared on the market over the past few months. These are supposed to be able to back up virtually any ATARI disk, even those protected by something called "bad sectoring." Many of the companies producing these products have bought ad space in the pages of this and other magazines.

A.N.A.L.O.G. has a responsibility to its other advertisers and to ATARI users in general. If the "super-dupers" being advertised in our magazine are contributing to the piracy of copyrighted software, it is not in the best interest of anyone to continue running them.

The reactionary way out of this dilemma would be to immediately reject all further ads for disk copiers. Instead, we decided it would be fairer (and more interesting) to test the copiers first to see if they really worked. We will also examine the technology of ATARI disk copying, and propose a set of protection standards for consideration by the ATARI community.


The Hardware.

Before discussing the operation of disk copiers, let's review the hardware that makes it all possible - the ATARI 810 Disk Drive.

The 810 is an intelligent drive. It contains its own 6507 microprocessor, memory buffers and a dedicated operating system that directly controls every reading, writing, and formatting function.

The 810 accepts commands from the main console over the serial bus. Only five commands are recognized by the 810 operating system: Read Sector, Write Sectors, Write Sector with Verify, Format Disk and Status Check. All ATARI disk I/O (including disk copying functions) works by using one or more of these fundamental operations.

It's important to understand that the computer can only tell the 810 what to do - NOT how to do it. That means that it's impossible to write a program that will make the 810 access a disk in a non-standard way. The ONLY way to accomplish this is by monkeying around with the drive, or with the disk itself.

The Disk.

When you format a disk, the 810 writes a predefined magnetic pattern consisting of 40 concentric rings or tracks. Each track is divided into 18 sectors which contain 128 data bytes apiece. Since there are 18 X 40 or 720 sectors, a standard ATARI disk can hold 720 X 128 or 92, 160 bytes of information.

The 810 also writes timing information and a unique indentification number onto each sector when it formats a disk. These sector headers cannot be altered once they are in place because the 810 doesn't know how to access them individually. You can play with the sector data all you like - but you can't touch those sector headers unless you completely reformat the disk.

The Copiers.

The principle of ATARI disk copying is very simple. All you do is read the data from each interesting sector into RAM, and write the data out to the same physical sectors on another disk. The copy disk should perform exactly the same as the original.

ATARI DOS II uses this method to dup licate disks. Whenever you create or modify a disk file DOS updates a map of "in-use" sectors called the Volume Table of Contents (VTOC), which is maintained at sector 360. When you select option "J" (Duplicate Disk), DOS checks the VTOC to find out which sectors are marked as being active. It then reads the contents of those sectors and copies them.

DOS ignores sectors that haven't been marked in the VTOC. Some early disk protection schemes took advantage of this fact by "hiding" important data in unmarked sectors. If you tried to copy one of these disks with DOS, you wouldn't get a complete copy and the program would fail.

The first ATARI "disk backup" programs were merely dumb sector copiers. These products (with provocative names like Mirror Image, Superdup and Lockpik) bypassed DOS altogether by talking directly to the disk drive. Each and every one of the 720 sectors on a disk was read and duplicated, whether or not DOS thought those sectors were important. The resulting copies included all the "hidden" data and ran just like the original.

Software manufacturers were understandably concerned about these copy programs. Piracy was rampant, and for a while it seemed as if there was no way to circumvent a dumb sector copier.

The Breakthrough.

Towards the end of 1981, a new type of ATARI disk protection was introduced which put an end to "dumb" sector duping. Pirates were bewildered by these innocent-looking disks which copied perfectly but would not run.

The disk manufacturers found a way to modify selected sectors so that they could not be read by a standard 810 drive. The application program included a routine that checked for these "bad" sectors. If they were readable, the program assumed the disk was a copy and crashed itself.

Imagine what happens when you try to "Lockpik" disk protected by bad sectoring. The copier will detect the bad sectors but will not be able to reproduce them because the 810 doesn't know how to write anything but good sectors. The resulting copy may contain, every byte of program data, but it will stubbornly refuse to execute.

Software publishers were delighted by the effectiveness of this new protection scheme. The pirates shuffled away to sulk - and, inevitably, to tinker.

The New Copiers.

Hackers are known for their cleverness and dogged persistence. It didn't take long for one of them to figure out a way to beat "bad sectoring."

It seems that if you write to a disk sector with your drive speed adjusted far above or below its normal setting, the written data will be screwed up so badly that a normal-speed drive won't be able to read it. A similar result can be obtained by sticking a piece of tape on the disk jacket and pulling on it during a write operation. This throws the drive alignment off just enough to produce a bad sector. These two discoveries have led to a second generation of disk copiers that allows repeated read/write access to any selected sector, making it fairly easy to produce bad format. First you perform a sector-for-sector copy of the source disk, noting the sectors that are bad. Then you go back and destroy the integrity of the noted sectors on the dupe. The copied software will never know what happened to it - and neither will the software author, if the person doing the copying is lucky.

Most of the copy programs in our listing are the second-generation type with provisions for bad sectoring. Some include additional utilities that allow you to directly examine and edit sector data, and perform a variety of other useful (and totally legitimate) housekeeping function. Each listing is followed by a brief comment which notes the strong and weak points of that particular product. Contact the manufacturer if you need more detailed information.

The manufacturers of these copy programs do NOT endorse the use of their products for the purposes of duplicating copyrighted software. All of them include strict warnings to this effect in their documentation, along with a defensive note emphasizing the importance of being able to back up valuable software. It is amusing that most of these same publishers are distributing their copy programs on heavily protected disks! Did I hear someone use the work "hypocrisy?"

Another Breakthrough.

Software publishers aren't as worried about second-generation copy programs as you might think. Why? Because they have ALREADY adopted ingenious new disk protection methods that can foil even the most elaborate software-based copier.

Again it was the disk duplicators who came to the rescue, this time with sophisticated duplicating machines that can do all sorts of weird things to the sector headers on an ATARI disk. I won't divulge the details here, but I can tell you that not one of the copy programs listed here can make an executable copy of a disk duplicated using these methods.

What's more, there will NEVER be a copy program that will allow an unmodified 810 to dupe these disks, because there is no way for an 810 to access individual sector headers. The only way out is to scan the entire disk, sector by sector, locating and bypassing the machine-language instructions that took for the special-format. This is a formidable task, especially if the code happens to be encrypted (and it nearly always is). So if your main reason for buying a "disk backup" program is to make dupes of Choplifter, Filemanager 800+, The Datasoft Compiler or any other current software hit for your friends, forget it!

What About Us Honest Guys?

The new disk protection technology has important implications for ALL software buyers, even the completely honest ones (yes, both of you). It is now more important than ever for software publishers to start providing separate backup disks with their products. Not just a mail-in coupon - I mean an extra physical disk, in the same package as the original. This is particularly true of systems and business programs, where an untimely disk failure can cause a lot of annoyance and expense.

Few things are more frustrating than an essential disk that crashes. The first prize for thoughtless software packaging goes to ATARI, for their disk-based version of Microsoft BASIC. Would you risk writing an important business program with this language, knowing that your only copy of the interpreter is a speck of dust away from total uselessness? Would you care to deal directly with ATARI in a time-critical emergency? I thought not.

It would cost publishers only a few dollars more to include a separate backup disk with their products. This simple precaution would go a long way towards protecting the interests of buyers and enhancing the professional image that ATARI software so desperately needs, It would also help reduce the temptation to produce unauthorized backups - a practice that usually leads to pirate copies at the next user's g roup meeting.

I don't think it's necessary to provide separate backups for games. But it would be an inexpensive comfort to have an extra copy on the flip side of the disk, just in case. This is definitely NOT recommended for professional programs. I know of at least one popular (and expensive) business-oriented program that comes only with a flip-side backup - a pointless courtesy if I misplace my disk.


What Do You Think?


A.N.A.L.O.G. is eager to hear your opinions on the issues presented in this article. I'd like to see feedback from everybody. consumers, authors, publishers and maybe even a pirate or two. We'll publish the most interesting replies, in our next issue. So get out your favorite word processing program (hopefully a legitimate copy) and start typing!