Introduction - Computer Busses - page 15

To give users some choice in their operating sys-
tem, the IBM PC was initially distributed with three
operating systems: PC-DOS (provided by Microsoft),
Digital Research's CP/M-86 and UCSD Pascal P-
System. Microsoft understood that to make their op-
erating system the standard, that they must provide
IBM with a good deal. Thus, Microsoft offered IBM
the royalty-free rights to use Microsoft's operating
system forever, for $80 000. This made PC-DOS
much cheaper than the other two (such as $450 for P-
System, $175 for CP/M and $60 for PC-DOS). Mi-
crosoft was smart in that they allowed IBM to use
PC-DOS for free, but they held the control of the
licensing of the software. This was one of the great-
est pieces of business ever conducted. Eventually
CP/M and P-System died off, while PC-DOS become the standard operating system for the
PC.
The developed program was hardly earth shattering, but has since gone on to make bil-
lions of dollars. It was named the Disk Operating System (DOS) because of its original pur-
pose of controlling the disk drives. Compared with some of the work that was going on at
Apple and at Xerox, it was a very basic system. It had no graphical user interface and
accepted commands from the keyboard and displayed them to the monitor. These commands
were interpreted by the system to perform file management tasks, program execution and
system configuration. Its function was to run programs, copy and remove files, create direc-
tories, move within a directory structure and to list files. To most people this was their first
introduction to computing, but for many, DOS made using the computer too difficult, and it
would not be until proper graphical user interfaces, such as Windows 95, that PCs would
truly be accepted and used by the majority.
It did not take long for the computer industry to start 'cloning' the IBM PC. Many com-
panies tried; but most of them failed because their BIOS were not compatible with IBM PC
BIOS. Columbia, Kayro and others went by the wayside because they were not totally PC
compatible. Compaq eventually broke though the compatibility barrier with the introduction
of the Compaq portable computer. Compaq's success created the turning point that enabled
today's modern computer industry. They produced sales of $111 million in the first year of
their operation, making it the fastest growing company in history.
In Japan, NEC bought a license on the 8086/8088. They improved the design and pro-
duced two Intel 'clones', called the V20 (8088-compatible) and V30 (8086-compatible). The
V-series ran approximately 20% faster than the Intel chips when running at the same clock
speed. Therefore, the V-series chips provided a cheap upgrade to owners of the IBM-PC and
other clones computers. Although these chips were pin compatible with the 8086 and 8088,
they also had some extensions to the architecture. They featured all of the 'new' instructions
on the 80186/80188, and also were capable of running in Z80 mode (directly running pro-
grams written for the Z80 microprocessor). Much to Intel's embarrassment, NEC refused to
pay royalties to NEC on the sale of their processors. Intel found that it was difficult to copy-
right the actual silicon design, and have since copyrighted the microcode, which runs on the
processor. The microcode for the 8086/8088 consisted of 90 different mini-programs. How-
ever, in a courtroom, NEC showed that they had not copied these mini-programs and had
designed their own.

Figure 1.7 IBM PC

At this time, Intel was loosing a great deal of their memory product to Japanese compa-