Information Technology Reference
In-Depth Information
10-micron technology, 3·4 mm
2
•
Silicon:
•
Addressable memory:
640 bytes
Intel then developed an EPROM, which integrated into the 4004 to enhance development
cycles of microprocessor products.
Another significant event occurred when Bill Gates and Paul Allen, calling themselves
the 'Lakeside Programming Group' signed an agreement with Computer Center Corporation
to report bugs in PDP-10 software, in exchange for computer time.
Other significant effects at the time were:
•
Ken Thompson, at AT&T's Bell Laboratories, wrote the first version of the Unix operat-
ing system.
•
Gary Starkweather, at Xerox, used a laser beam along with the standard photocopying
processor to produce a laser printer.
•
The National Radio Institute introduced the first computer kit, for $503.
•
Texas Instruments develops the first microcomputer-on-a-chip, containing over 15 000
transistors.
•
IBM introduced the memory disk, or floppy disk, which was an 8-inch floppy plastic disk
coated with iron oxide.
•
Wang Laboratories introduced the Wang 1200 word processor system.
•
Niklaus Wirth invented the Pascal programming language. BASIC and FORTRAN had
long been known for producing unstructured programs, with lots of GOTOs and RE-
TURNs. Pascal was intended to teach good, modular programming practices, but was
quickly accepted for its clean, pseudocode-like language. Today it still survives, but has
struggled against C/C++ (mainly because of the popularity of Unix) and Java (because of
its integration with the Internet), but lives with Borland Delphi, an excellent Microsoft
Windows development system.
1.2
8008/8080/8085
In 1974, Intel was a truly innovative company, and was the first to develop an 8-bit micro-
processor. These devices could handle eight bits (a byte) of data at a time and were:
•
8008 (0.2 MHz, 0.06 MIPS, 3500 transistors, 10-micron technology, 16 KB memory).
•
8080 (2 MHz, 0.64 MIPS, 6000 transistors, 6-micron technology, 64 KB memory).
•
8085 (5 MHz, 0.37 MIPS, 6500 transistors, 3-micron technology, 64 KB memory).
These were much more powerful than the previous 4-bit devices and were used in many
early microcomputers and in applications such as electronic instruments and printers. The
8008 had a 14-bit address bus and could thus address up to 16 KB of memory, and the 8080
and 8085 had 16-bit address busses, giving them limit of 64 KB. Table 1.1 outlines the basic
specification for the main 8-bit microprocessors. At the time, Intel's main product area was
memory, and microprocessors seemed like a good way of increasing sales for other product
lines, especially memory.
