Introduction - Computer Busses - page 27

increased to 1.5 MIPS with a 10 MHz clock and 2.66 MIPS with a 12 MHz clock.
Commodore was never slow at developing their products. After the success of the Vic-
20, in 1981, they released the Commodore 64 in the following year. It sold for $600 and had
an excellent specification based around the new 6510 processor, and was released with
64 KB RAM, 20 KB ROM, sound chip (the first PC to have integrated sound), eight sprites,
16-colour graphics, and a 40-column screen. It was the first personal computer with an inte-
grated sound synthesizer chip. They then released a whole range of peripherals, such as the
VIC Modem ($110). Commodore also moved into the business market, with the BX256 and
B128 computers for $3000 and $1700, respectively. The BX256 was a 16-bit multiprocessor
computer. It included 256 KB RAM, Intel 8088 for CP/M-86, 6509 CPU, 80-column B/W
monitor, built-in dual disk drives, and three-voice sound. The B128 computer featured
128 KB RAM, 40 KB ROM, 6509 CPU, 5.25-inch floppy drive, three-voice sound chip, car-
tridge slot, and an 80-column green screen.
At Sinclair, the ZX81 had been an unbelievable success and, knowing that alone they
could not succeed in the USA market, they signed an agreement with the Timex Corporation
to license Sinclair computers in the USA. By the end of 1982, Sinclair Research had sold
over 500 000 ZX81s in over 30 countries. Atari also become a major computer company with
the Atari 800. Its main feature was an advanced graphics display. Radio Shack also released
the powerful TRS-80 Model 16. It used a 16-bit Motorola MC68000 microprocessor, a Z80
microprocessor, had 8-inch floppy drives, and an optional 8 MB hard drive. At the same time
as Compaq were releasing their portable, Radio Shack produced the TRS-80 Pocket Com-
puter; unfortunately, it was relatively slow as it used a 1.3 MHz 8-bit microprocessor, with a
26-character display.
DEC also finally decided to enter the personal computer market with the dual-processor
Rainbow 100. It had an excellent specification with both a Z80 and an 8088 microprocessor,
and could run CP/M, CP/M-86 or MS-DOS. Unfortunately, at $3000, it was too expensive
for the market, which was already hot for the IBM PC.
1983 was a mixed year for IBM. They continued their success with the released of the
IBM PC XT. It sold for $5000 and had a 10 MB hard drive, three extra expansion slots, and a
serial interface. In its basic form it had 128 KB RAM, and a 360 KB floppy drive. With the
success of PC-DOS 1.0, IBM followed it up with PC-DOS 2.1. On the downside, IBM re-
leased the IBM PCjr, which cost $700.
The greatest winners in 1983 were the newly created Compaq Computers, and Microsoft.
In their first year, Compaq sold 47 000 computers, with a turnover of $111 million (and
raised $67 million on their first public stock offering). They would eventually reach the $1
billion within five years of their creation.
The other winner was Microsoft who knew that they had to completely rewrite the MS-
DOS operating system, so that it coped better with current and future systems. For this they
introduced MS-DOS 2.0, which supported 10 MB hard drives, a tree-structured file system,
and 360 KB floppy disks. They had quickly released the potential of the IBM PC, and re-
leased XENIX 3.0 (a PC version of Unix), Multi-Tool Word for DOS (which would eventu-
ally become Microsoft Word 1.0), as well as producing the Microsoft mouse (which sold for
$200, with interface card and mouse). Microsoft also announced, in 1983, that it would be
developing Microsoft Windows (initially known as Interface Manager), which would even-
tually be released in 1985. At the same time as Microsoft announced Windows, IBM was
developing a program called TopView, and Digital Research was developing GEM (Graph-
ics Environment Manager). These programs would use DOS as the basic operating system,
but would allow the user to run multiple programs. The great problem with TopView was
that it was text based and not a graphical user interface (GUI, or 'gooey'). Even allowing for