Disk ][ And You

by John Covington

Finally! !! Disk II is out. If you’re lucky, you will be able to play with one in your local computer store until yours arrives from Cupertino. That is what I have been doing this last week, and this article comes from using the disk and my varied background in Data Processing. Hopefully, I’ll be able to explain some of the HOWS and WHYS of the disk system and clear up some of the blind spots in Disk II’s documentation. So let’s get on with it and explore the mysteries of DOS.

DOS is simply short for DISK OPERATING SYSTEM, the heart of Disk II. With it, Apple is able to talk to the disk and treat it like any other 110 device. The DOS is just a program (which resides in the top of RAM) so like Applesoft, if you write over it, you can kill it. However, with normal use, you don’t have to worry about that. If you are like me and have only 16K of RAM, the DOS will lock you out of using HIRES, because HIRES Page 1 uses your upper 8K of RAM. Now, let’s bring the DOS up and find out how to use it.

First, follow the instructions that came with the Disk System and plug the controller card into slot 6 in your Apple (with the power off). Then connect the ribbon cable from the drive into the controller card connector marked “Drive 1” (on the top of the card) and power your Apple up and hit reset twice. Insert the master diskette in the drive and type a 6 (for slot number), followed by Control P. This will bootstrap in the DOS and bring the disk system up. If all goes well you will see some titles and an Integer Basic prompt. This means DOS is up and you can begin running programs.

One of the first to run is the COpy program, but there is a hitch; it requires two drives. I’m sure the owner of your local computer outlet will let you run this program in his store, using your drive as the second drive. The purpose of running the copy program is to duplicate your master. It may save both of you a lot of headaches later. (We found out the hard way •… ed)

The reason is your master can be lost in a number of ways, ranging from oxide breakdown to operator error. Therefore it is prudent to have a backup disk to recover from.

To copy your master, you must first initialize a blank disk. To do this, boot the DOS up and then enter a short Integer Basic program (as per example) and use the INIT routine as follows:

INIT (program name), V{vol. no.), S{slot no.), D{drive no.).

Then run the COPY routine and Disk II will make you a second master.

The INIT command INITializes new disks. Because the Apple system uses soft sector drives, the floppies must be formatted to fit the DOS software. Any
mini-floppy has 35 tracks (similar to a track on a phonograph record, except it does not spiral in; it meets itself after one revolution. ) each of which must be divided into a certain number of sectors (a sector is where the data actually goes, and is composed of 256 bytes). To perform the INIT, you must have an Integer Basic program in RAM, which serves as a model for the formatter. It can be any runable Basic program, but keep it short, as this program will automatically run each time the disk is booted. The short program listed on Page 4 will serve as well as any, and will also call the catalog up for you each time you boot the disk up. Well, I guess I’ve given you enough to make you dangerous!


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About the Author

Bill Martens

A.P.P.L.E. Chairman of the Board and Club president -- Bill worked for the founder, Val J. Golding and A.P.P.L.E. from 1981 to 1982. In 1999, he began archiving the materials which were distributed and sold by A.P.P.L.E.. That project led to the group that remained of A.P.P.L.E. Bill was involved in the financial industry in Tokyo and has over 20 major office infrastructure projects to his name. In March 2001, he retired to write books and to spend more time pursuing personal interests. As the president of the users group, Bill is in charge of distribution of Call-A.P.P.L.E. magazine as well as the organization of this web site. Bill currently resides in Tokyo, Japan and Shelton, Wa splitting time between the places.