WHY YOU WANT DOS 2
Where to get it, how to use it!by JACK POWELL, Antic Technical Editor
A guide for new Atari 1050 Disk Drive owners who may wish to do themselves a favor and use Atari DOS 2.0S, instead of the inferior and incompatible DOS 3 which was supplied with their drive.
Because of sharply lowered prices, there has been a swift increase in the number of new Atari owners. If you bought a 1050 Disk Drive recently, you were supplied with the newer DOS 3 Disk Operating System and a few fairly mystifying booklets. DOS 3 provides increased storage density, but is virtually incompatible with just about every product on the market. Antic strongly recommends that all new owners use the earlier DOS 2.0S until they feel comfortably knowledgeable with DOS functions. DOS 2.0S is available on many Antic public domain disks (including Moon Games, Antic Exclusive Games #1 and Super Utilities #1) or can be found on any of the Antic monthly subscription disks. But since you don't have documentation for DOS 2.0S, we offer the following tutorial.
WHAT IS DOS?
The first thing you should understand is that DOS is simply a program. Period. It is written in machine language and works like any professional game or word processor that starts up as soon as you boot (turn on) your computer.
Just as a game, when booted, loads into memory and tells your computer to put animated characters on the screen, DOS, when booted, loads a program into memory that tells your computer how to deal with your disk drive.
Atari DOS 2.0S is really two programs, or disk files: DOS.SYS and DUP.SYS. When you turn on your computer with a disk containing DOS.SYS and DUP.SYS, the DOS.SYS program is automatically loaded and BASIC is enabled (if you haven't pressed the [OPTION] key). DOS.SYS turns you over to BASIC and the READY prompt appears. You can now do anything you wish in the BASIC language, but DOS.SYS is still there waiting to act upon any BASIC commands it recognizes.
One of these BASIC commands is: DOS. This can be confusing because, when you type DOS, the DOS.SYS program in memory runs another program called DUP.SYS and you find yourself looking at a menu of choices. You are now no longer in BASIC. You are in DUP, which stands for Disk Utilities Package.
Still with us? To make things a bit more confusing, we should tell you that when you type DOS from BASIC, this is always called "going to DOS." It might be clearer if it were called "going to DUP", but it's not. If you hold down your [OPTION] key when booting the DOS disk, you will also find yourself in the DUP.SYS menu. This is because, after loading, the DOS.SYS program has nowhere to go, so it loads in the DUP.SYS program.
Now we're at the meat of it. The menu screen shows selections labeled A through O. Keep in mind that you are now running a program that serves no other purpose than to manipulate the files on your disks. We cannot cover all the menu options in this article, but we'll get you off to a good start by explaining the most important options. For complete documentation on DOS 2.0S, we recommend Your Atari Computer by Lon Poole. (458 pages. $17.95. Osborne/McGraw-Hill. 2600 10th Street. Berkeley, CA 94710. (415) 548-2805.) Here are the most commonly used DUP.SYS menu commands:
To find out what files are on your disk, press [A][RETURN][RETURN]. If the files scroll beyond your screen, you can temporarily halt the scrolling by holding down [CONTROL] while pressing . Repeat this same sequence to start the scrolling again. While you're in DUP.SYS, you can put other compatible disks into your drive and manipulate their files.
When you press [B][RETURN]. you will be returned to whatever cartridge is in the machine. If there is no cartridge, you will return to the built-in BASIC. (You can also return to BASIC any time you press the [SYSTEM RESET] key.)
Be careful here! There is no going back.
This might be a good place to talk about Reading and Writing. Many of the disk utilities in DUP either read from the disk or write to the disk. Reading will harm nothing, but writing can permanently erase information that was on the disk. If you wish to avoid any writing on a particular disk, place a write-protect tab tape over the notch on the side of the disk. This blocks a beam of light in the drive and tells it your disk is protected. If you attempt a write command from DOS onto a write-protected disk, you will get an error message, which is better than losing a file.
When you press [D][RETURN], the computer will prompt, DELETE FILE SPEC. Simply type in the name of the file you wish deleted. With a single drive, you can leave off the D: and just type in the filename. This is true of all DUP.SYS commands. Press [RETURN] and the computer will ask you if you really want to delete that file. Do you?
You can change the name of any file by simply pressing [E][RETURN] and then typing in the old filename followed by a comma and the new filename. Caution! It is not a good idea to have more than one file with the same name. If this happens, you will only be able to access one of those files.
A locked file is protected from any change. Press [F][RETURN], then type in the filename. When you now look at the directory (press [A][RETURN][RETURN]), your locked file has an asterisk [*] before it. It can no longer be deleted or renamed. If you're in BASIC, you cannot SAVE to a file that has been locked.
This might be the place to mention the subject of Wild Cards. Just as in a deck of playing cards, Wild Cards can stand for anything, depending on where they are placed. There are two kinds of Wild Cards, and we'll explain the most commonly used type here.
When typing in a filename (which can be as many as 8 characters followed, if you wish, by a period and a 3 character extender) you may substitute any portion of the filename or extender with an asterisk [*]. DUP.SYS will ignore everything to the right of the asterisk in either of the 2 fields. Thus: D:AT*.BAS will be seen as any and all files that begin with AT and have an extender of .BAS. If you wish to lock all the files, press [F][RETURN] followed by *.* . If you only wish to lock those with BAS extenders, enter *.BAS
This is exactly the opposite of [F] Lock. The [F][RETURN] and [G][RETURN] commands are a good place to experiment with Wild Cards. You can't do much damage here.
H-WRITE DOS FILE
Here is your opportunity to create new DOS 2.0S disks. When in DUP. SYS, insert a blank disk and format it using the I option (described below). Now press [H][RETURN], answer the prompts, and both DOS.SYS and DUP.SYS will be written to the new disk. This should always be done before any files are placed on the new disk.
WARNING! This function will wipe your disk clean. It will override locked files and there is no turning back. You will be given a couple of prompts, however, before committing yourself. A disk that is to use DOS 2.0S must be formatted by DOS 2.0S. You cannot write DOS 2.0S on a disk that has been formatted with DOS 3.
This option will permit you to copy an entire DOS 2.0S disk and all its files. It will not duplicate professional software that has been copy-protected. You will be given a series of prompts in which you must trade back and forth between the Source disk and the Destination disk. The Source disk is the disk with the original files, the Destination disk is the disk the files are going to. For safety's sake, place a write-protect tab on your Source disk.
This will LOAD and in many cases, RUN a binary, or machine language program. These files will usually have an extender of .EXE, .BIN, .COM, or .OBJ. Simply type [L][RETURN] and follow the prompt with the filename. If the file is not a binary file, you will be told
Use this [O] [RETURN] command when you wish to move one file from one disk to another. As in the [J][RETURN] command above, you will be prompted to trade back and forth between Source and Destination disks. Again, use a write-protect tab on the Source disk.
ACCESS FROM BASIC
If you're like many new Atari users, you will soon get quite familiar with the commands to SAVE or LOAD a program from BASIC. But you may be a bit confused about LISTing or ENTERing a program. These four commands are a function of the BASIC language and are the same no matter what DOS you use.
When you type: SAVE: "D:MYGAME.BAS" from BASIC, the disk whirrs and you have copied the BASIC program in memory to the disk (device D:) under the filename MYNAME.BAS. The program is still in memory and it is now also written on the disk. By using the command SAVE, the program is written on the disk in what is called a "tokenized" form. This simply means that it's there in a kind of code.
If you want to know what this tokenized code looks like, LOAD a program into memory and type: SAVE "S:". You'll see a bunch of garbage scroll across the screen. This is the tokenized program. If you simply type LIST, the same program will scroll across the screen in standard ATASCII form and be quite readable. Now, if you type: LIST "D:MYGAME. LST", this same program will be LISTed to disk, but will now be on disk in the same ATASCII form that it was when listed on the screen.
A SAVEd program may be RUN from disk or LOADed from disk. A LISTed program may only be ENTERed from disk. For the example above, you would type: ENTER "D:MYGAME.BAS"
Once ENTERed, it may then be RUN. Also, if a program is already in memory when a second program is ENTERed, the second program will merge with the first. This is not true of a LOADed program.
Caution! do not type LIST "D:MYGAME.LST" when there is nothing in memory. You will then have written a file to disk consisting of nothing and possibly wiped out a file of the same name that was already there. If you have a printer, you may list your program to it by typing: LIST "P:". You have now listed your program to the printer device.
The best way to master all these commands is to put together a disk of duplicated program files and experiment. As long as you use backups you have nothing to lose and the computer will be only to happy to teach. you.