Beginners Corner
By Grant Kwai
Copyright (c) 1991 Apple Users' Group, Sydney
Republished from Applecations, a publication of the Apple Users' Group, Sydney, Australia.
Over the last few months, I have met with a number of relatively new Apple // users. To my astonishment, I was amazed by how little they actually knew about the Apple //, particularly anything which went beyond the limits of a menu system of operating. They were what I would stereotype as an IBM user, familiar only with programs and knowledge of little else (though I know many IBM 'power users'.)
It then struck me that perhaps the may be many people in the Apple Users' Group who are in the same boat. Whether they thought it was too technical to get into and use DOS, or they didn't know where to start, this article is dedicated to those 'new users' unfamiliar with anything other than other people's programming.
The program which they all seemed to be able to use was Appleworks. Why was this? Was it the power of the program? or the ease of its operation? (in particular, the easy to use menu system). I tend to lean towards the ease at which a beginner can access such a powerhouse program. A person can simply run Appleworks without any prior knowledge in a matter of minutes. It is full of menus which makes it particularly simple for someone to understand what does what.
This perhaps is what makes DOS and ProDOS (and even Integer basic or CP/M) seem so technical and a world better left to the professionals. Think that no more.
Firstly, we will start with what DOS really is.
DOS stands for Disk Operating System. ProDOS is a Professional Disk Operating System (The more recent and more powerful version. Most new commercial programs these days run under ProDOS). Without DOS, your Apple // would not know how to access your disks e.g. how to load your BASIC program. Basically, DOS is a program which is loaded into RAM, (Random Access Memory - Can be thought of as the memory of the computer in that data is stored in it) each time you boot up a disk. Generally, unless you do something drastic, DOS will remain in your Apple until you turn your computer off.
Since it is a Disk operating system, it has a number of reserved words which are used to access your disks. Some of these which you may be familiar with are LOCK, UNLOCK, CATALOG, RENAME etc. These are all part of DOS. BASIC (Beginners All-purpose Symbolic Instruction Code), also has a number of reserved words such as LIST, GOTO, LET, FOR etc. When you type something in from the keyboard, your computer first checks DOS to see if it is a command to access a disk. If not, it will then check to see if it is a reserved BASIC command. If the computer still doesn't recognize it, then that is when you get a SYNTAX ERROR. e.g. if you type in CATALOGUE, your Apple // will search DOS, it will find it not in its vocabulary, it will then search BASIC, will once
again not recognize it, so it will then tell you it must be an error. All this takes place is a fraction of a second.
[A reserved word is a special word, or command that the computer has embedded either in DOS or BASIC so as to know what function you want performed. If you were allowed to use these words for any other purpose, you would seriously confuse your Apple.]
Now that you know the difference between DOS and BASIC, why don't you try it out and see how it works. To get into DOS, load up your system master disk or some other disk which has DOS on it. As stated above, there are two types of DOS and two types of BASICs available. You can tell which one you are in by referencing the following. For DOS 3.3, you will be greeted, upon booting up your disk by the ']' prompt in the lower left portion of your screen. For ProDOS, you will see a screen displaying something like PRODOS 1.1.1 on your screen with a copyright notice by Apple Inc. You should then be greeted by the DOS prompt of ']'.
If you are using ProDOS then if you type CAT (40 column screen) or CATALOG (80 column screen, implemented with a 'PR#3' command) and hit return, you will notice that on the disk you should have a program called PRODOS and possibly BASIC.SYSTEM.
The two types of BASIC (Applesoft basic and Integer basic) can be easily determined by the type of prompt you get (A prompt is the character next to which your typing appears when the computer accepts input from the keyboard.) For Applesoft, you will get the familiar ']' prompt. This is the most common BASIC, and the one in which you will most likely always use. Integer BASIC displays the '>' prompt. Many older programs may require Integer BASIC, but hardly anyone uses it these days since it was invented before the disk drive era.
The DOS 3.3 catalog
In a DOS 3.3 catalog, you will see something like the following:
DISK VOLUME 254
*A 011 HELLO
B 050 INTBASIC
*I 036 TOMATO PLANTS
T 015 DATA FILE
Here you will notice a variety of information is available at your finger tips. Starting with the top line, most disks will start with DISK VOLUME XXX, where XXX is a number between 0 and 255. This has no real significance.
You will then notice that on the first column some of the programs have a '*' next to the letter. This signifies that the program is 'LOCKED'. When you lock a file, it can not be
deleted from DOS with the normal DELETE command. This protects the file from unintentional erasure. To delete such a file, you will be required to UNLOCK the file first. An UNLOCKED file is shown by no asterisk in the first column. For example, the DATA FILE and INTBASIC files above are unlocked and the HELLO and TOMATO PLANTS files are locked. The DATA FILE and INTBASIC files can be deleted with the DELETE command.
Next you will see the letters of; A,B,I,T. What these stand for are Applesoft basic, Binary file, Integer basic and text file respectively. Applesoft files are BASIC files which can be entered into the computer at the ']' prompt then saved to disk with the SAVE command. You can then RUN these programs or LOAD them into memory. programs preceded by the 'B' file type must be BRUN to run or BLOADed to load into memory. These are binary files which are usually programs, programmed in machine code. Machine code is the computer's native language and a program written in machine code is therefore generally executed faster. However, programming in machine code is much harder than in Applesoft, so we will leave it at that.
Integer basic programs must be loaded from within Integer basic and therefore you must have the '>' prompt. To load Integer basic, you should find a file on your system master disk called INTBASIC, or something similar to that. You must BRUN this program first before you can RUN any 'I' type programs.
Finally we have the 'T', text file. Such a file is used for storing data for a Applesoft or Binary program. Such information may be high scores for a game, a phone number list, or a word processor document. There are numerous ways to access a text file. For example, an application program, such as a word processor, could access the text file while keeping the details hidden from you, or you could directly OPEN, READ, WRITE or CLOSE the text file from within an Applesoft basic program.
A PRODOS catalog
A ProDOS catalog varies slightly from that of the DOS 3.3 catalog. If you view such a catalog in the 80 column mode, you should see something like:
Blocks Free: 179 Blocks Used: 101 Total Blocks: 280
The asterix '*' still represents whether or not the file is locked as in the DOS 3.3 catalog. However you will notice that filenames under ProDOS cannot contain spaces, therefore you have a full stop between each word in a filename (e.g. BASIC.SYSTEM, DATA.FILE).
Under the title 'Type', you will notice a slight difference to those in the DOS 3.3 catalog (there are many other file types under ProDOS which were not listed for brevity). Each file type has been condensed into a three character identifier (e.g. SYS, BAS, BIN, TXT). SYS stands for a system file, BAS for BASIC, BIN for Binary and TXT for text. All RUNable files under ProDOS can be simply put into operation by typing '-XXXXX' where XXXXX is the filename. This will work for file of SYS, BAS and BIN filetypes. Alternatively, you can for basic programs, RUN them or LOAD them, and for BIN files, BRUN them or BLOAD them as required.
The next column simply shows you the size of the file in blocks. The larger the number, the larger the file.
The next two columns contain something new to DOS. ProDOS adds the function of a data/time stamping ability. Under the 'modified' heading you will see the date and time the program was last saved. The 'Created' column signifies when the program was created.
In the last column, 'Endfile', we are told the length of the files in bytes (a byte is one character, letter, digit etc).
Finally down the bottom of the catalog we have the blocks free, the blocks used and the total blocks. These tell use how much room it still free on the disk for future files, how much storage space has been used by the files already on the disk and the total amount of storage space available on the disk. [Note, 7 blocks are already use by ProDOS on the disk even without any files, so technically, only 273 free blocks are left].
One little function possible under ProDOS is the ability to catalog just one type of file. That is, just BASIC files, SYS files etc. To do this, simply type:
CATALOG,TXXX
where XXX is the file types three character abbreviation.
Well, after all that I hope that you have learnt the noticeable differences between DOS 3.3 and ProDOS. Now you should be able to look at your disk catalog and understand
everything. If there are any other areas you would like covered then please drop the editor a note.
Permission is hereby granted for non-profit user groups to republish this content. PLEASE CREDIT THE AUTHOR AND THE SOURCE: Applecations, publication of the Apple Users' Group, Sydney, Australia