Introduction - Computer Busses - page 12

• Cray Research . Cray Research developed one of the first supercomputers with the Cray-

1. It used vector-processing computers and was a direct attack on IBM's traditional com-
puter market. This caused major rumbles in IBM which was seeing its market attacked
from three sides: the personal computers (which started to show potential in lower-end
applications), the minicomputer (which were cheaper and easier to use than the main-
frames) and from the supercomputers (at the upper end). Processing power became the
key factor for supercomputers, whereas connectivity was the main feature for mainframe
computers. As DEC has done, Cray concentrated on the scientific and technical areas of
high-performance computers.

• Wang Laboratories . Wang emerged in the computing industry with its innovative word-

processing system which used computer technology, instead of traditional electronic
typewriters. It initially cost $30 000.

• MITS . After the success of the Altair 8800, MITS released the Altair 680, which was

based on the Motorola 6800 microprocessor.

And for microprocessors there were five major competitors:

• Zilog . Zilog released the 2.5 MHz Z80; an 8-bit microprocessor whose instruction set was

a superset of the Intel 8080.

• AMD . Intel realized that they must create alliances with key companies, in order to in-

crease the acceptance of the 8080 processor. Thus, they signed a patent cross-license
agreement with AMD, which gave AMD the right to copy Intel's processor microcode
and instruction codes.

• MOS Technology . MOS Technology released the 1 MHz 6502 microprocessor to a great

reception, and started a wave of classic computers, such as the Apple II. The 6502A
processor would increase the clock speed.

• National Semiconductor . Released the SC/MP microprocessor, which used advanced

multiprocessing.

• Texas Instruments . After years of innovation at Intel in producing the first 4-bit (4004)

and the first 8-bit processor (8008), it was TI who developed the first 16-bit microproces-
sor: the TMS9900. Its first implementation was within the TI 990 minicomputer. The
processor was extremely advanced for the time, but, unfortunately, TI failed to provide
proper support for the processor. Its main failing was that there was no usable develop-
ment system (something that Intel and Motorola always made sure was available for their
systems).

The following year belonged to Apple, Commodore
and Radio Shack, who released the excellent Apple II,
the Commodore PET and the TRS-80, respectively, to
an eager market. In 1977, the Apple Computer Com-
pany was incorporated, and the employees moved to
California. The Apple II computer sold initially for
$1300 and used the 6502 CPU, had 4 KB RAM, 16 KB
ROM, a QWERTY keyboard, eight slot motherboard,
game paddles, graphics/text interface to colour display
and came with the Applesoft system (built-in BASIC
provided by Microsoft). Soon, Steve Wozniak was
working on software for a floppy disk controller.

Figure 1.6 TRS Model I