The purpose of this article is to give a beginner's guide to loading files from DOS 3.3 disks. It is written from the point of view that the user has little or no knowledge of the Apple II platform. Where a command is written such as RUN FILENAME or UNLOCK FILENAME, the word FILENAME should be replaced by the name of the file you are trying to use.

Since Apple announced the abandonment of the Apple II platform in favour of the Macintosh, Apple II computers of varying models have become exceptionally cheap or are often given away. Many users get hold of an Apple II without manuals or any knowledge & want to use the disks that often accompany the computer but don't know how to access the information.

Typically, disks are formatted using either DOS (Disk Operating System) version 3.3 or a version of the ProDOS, which is a later DOS Apple released. There are a number of ways to access the information on any DOS 3.3 disk, but typically, you insert the disk in question & turn on the computer. You shouldn't insert a disk into a running drive as it is possible to cause damage to both the disk & the disk drive.

If the disk is formatted with DOS 3.3, it will automatically load the instructions for the computer to access the disk (hence the name DOS), then load a greeting program, which in DOS 3.3 is usually called HELLO. The HELLO file can be presented in any number of ways, such as to automatically load a program residing on the disk, present you with a list of the programs on the disk in a menu you can choose from or it may simply load the DOS & give you a flashing cursor & a BASIC prompt (]).

If you are presented with a menu from which to choose, all the better & the HELLO program will let you automatically run your program. However, if you are presented with a BASIC prompt & a flashing cursor, you need to find out what's on the disk before you can run any of the programs on it.

Firstly, you'll need to call the contents of the disk up using the CATALOG command. As you might have guessed, this particular command will give you a catalogue or list of the contents of the disk. To use this command, from the BASIC prompt, type CATALOG & then hit RETURN. The disk drive will start up & the contents of the disk will be displayed on the screen. If the disk contents don't display, there's a chance that this is a specially protected disk & you will need to resort to more complicated measures to inspect the contents than this article outlines.

Once you have a list of contents, it should look something like the following:

DISK VOLUME 254

A 005 HELLO

A 024 BASICPROG

*T 010 TEXTINFO

T 006 MORETEXT

*I 015 COOKING

A 065 LOTTOPICKER

B 034 HIRESPIC

B 143 GOODGAME

B 063 INTEGER

*B 120 RASTER BLASTER

A 006 PICLOADER

]

Okay, now you have a CATALOG on the screen, it may look a little difficult, but it's not really very hard to run some of these. Looking down the left hand side of the column, next to the letters, you'll notice that some of the files have an asterisk (*) next to them. Each file marked with * means that it is locked & cannot be deleted unless you lock it.

To lock a file simply type LOCK FILENAME & press RETURN. The disk drive will start up & the file will be locked. If you then type CATALOG again, you'll notice that the file will now have an * beside it. To unlock a file, simply type UNLOCK FILENAME & press return.

Next, the letters in the column next to the * denote the type of file it is. An A denotes an Applesoft BASIC (Beginners All-purpose Symbolic Instruction Code) program & you can execute one of these by simply typing RUN FILENAME & pressing return. The disk drive will start & your program will run. An Applesoft program is usually designed to run without any extra loading procedures.

A letter B next to the file is slightly more complicated. This means that it is a Binary program or is written in machine language (another programming language similar to Applesoft BASIC) Not all Binary files can be run directly from a command. To try, simply type BRUN FILENAME & press return. If the program is executable, it will automatically run the contents of the file. If not, it may simply return something like I/O ERROR or perhaps it may cause the machine to crash into machine language giving you a prompt something like:

*0800: AE F8 90 9C

*

If this happens, the simplest way is to restart the computer by either turning it off or by performing a warm boot, which is done on Apple //e, //c, //c+ & IIGS computers by holding down the Open Apple (the Apple which is outlined) & CONTROL keys then pressing the RESET button. On earlier machines like the Apple II Plus, it is easier to switch the computer off, wait about 10 seconds, then switch it back on. You could also try from the * prompt, C600G, which will reboot the computer from the machine language prompt.

A letter I beside the name of your chosen file usually means that it is an Integer BASIC program (an earlier version of Apple BASIC than Applesoft). These are not able to be run without the Integer BASIC loader, which is available on the DOS 3.3 System Master disk. If you have an Integer loader, once you have run this loader, then you simply type INT & press RETURN to enter Integer BASIC & type RUN FILENAME in the same way you would run an Applesoft program.

The letter T beside a file indicates that it is a text file. Text files are usually used for data storage for other programs or contain executable code used by other programs. It is possible to open these files from a BASIC prompt, but this requires more knowldge than the scope of this article can cover.

Hopefully this article will give new Apple II users some knowledge about the mysterious disks that came in a box with your newly acquired computer.

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