APPLE

Installing an Apple I I I Driver
or What Have I Gotten Myself Into?
by Mike Kramer
Houston Area Apple Users Group
THE INITIAL SHOCK
When my office Apple / / / arrived a little over a year ago,
everyone was anxious to see what it could do. This naturally
included seeing it print something. After impressing everyone
with being able to enter a simple VisiCalc spreadsheet without
reading the manual, I lost all credibility when it wouldn't print
anything on the Epson printer. After they left, I got out the
owner's manual and discovered that Apple /// software
normally comes configured for serial printers connected to the
built-in serial port For me to print on the Epson printer
connected to the Universal Parallel Interface Card (commonly
called a UPIC) in Slot 1, I needed to install and configure a
parallel driver. What's more, I needed to do this with every boot
disk I had or would ever have, that would use the parallel card.
What I didn't realize at that point was that the source of my
"difficulty" was in fact one of the outstanding features qf the
Apple I I/. That feature is Apple I I/' s ability to execute
programs written with little regard to what kind of output device
would be used (also known as device-independent 1/ 0).
Without the programmer knowing ahead of time where
program output will go, output from Apple / / / programs can
be directed to a printer, the screen, a named disk file, etc., at run
time.
The price we pay is having to generate appropriately
configured drivers into any new software we get Not much of a
price when you know how, and you should know how to install
drivers if you intend to use an Apple ///. This is particularly so
since generating drivers for the Apple /// is not something the
typical store person knows very much about (there are
exceptions, however). So after this rambling introduction, get
out your Standard Device Drivers Manual and, if you have one,
the UPIC Parallel Interface Installation and Operating Manual,
and let's find out how to do it
What is a Driver?
First, let's review what a driver does. The Standard Device
Drivers Manual describes peripheral devices such as the
keyboard, video display, speaker, and input/ output (1/0) ports
as the " senses" of the computer, i.e., the eyes, ears, etc. These
senses are connected to the Sophisticated Operating System
(SOS) by device drivers which perform four functions:
- Process data generated by programs and send it to the
devices as output
-Process data generated by the device and send it to programs
as input
- Permit programs and SOS to control the device and the
driver itself.
- Permit programs and SOS to read the status of the device
and the driver.
Most of you don't need to be concerned with the specifics of
what the drivers do, but it should help your understanding if
you're generally aware of what they do and why they are there.
System Configuration Program
One of the disks provided with the Apple / / / is the System
Utilities Disk, which includes the System Configuration Program
(SCP). This is the tool for adding or removing device drivers, or
changing the parameters that control their operation. You may
have noticed when cataloging disks that every bootable disk
has three special files named SOS.KERNEL, SOS.DRIVER,
and SOS.INTERP. SOS.KERNEL is SOS itself. SOS.INTERP is
the machine language "interpreter" which runs on bootup.
This can be Business BASIC, Pascal, Apple Writer///, VisiCalc,
etc. Unless you become very, very good with the Apple /// you
will never create vour own SOS.INTERP.
SOS.DRIVER ~ontains the system configuration, including
the drivers and their control parameters, the number of disk
drives connected, the video display character set, the ASCII
character codes assigned to each key on the keyboard, and the
slot assignments for any interface cards plugged into the
connectors inside the Apple.
Reading a Driver File
First, let's find out which drivers are in fact currently on a boot
disk Place your System Utilities diskette in the built-in drive and
boot it Next, run the SCP by moving the cursor to the third line
and pressing RETURN. To look at and possibly change any of
the information defining how your Apple /// operates, tell the
SCP to READ in the SOS.DRIVER file from the diskette of
interest by placing the cursor over "Read a Driver File" and
pressing RETURN.
Why not read in the SOS.DRNER file from the Utilities
diskette itself and configure it (you are using a backup copy of
the original disk, aren't you?), so that you can list directories on
your printer rather than always listing on the screen. The SCP
defaults to .Dl/ SOS.DRNER, so all you have to do is press
RETURN. To read from a disk in the external drive, change.DI
to .D2 before pressing RETURN.
After a few seconds, the current driver configuration will be
displayed on the screen as shown on Page 12 of the Standard
Device Drivers Manual. Note that each driver has a unique
name beginning with a dot (looks suspiciously like a period). A
driver can have any name as long as it begins with a dot
22 Apple Orchard