Invention of theTransistor & Computer

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Invention of the Transistor and Computer

By Jack Handler, KB2BCC                    

Dr. John Bardeen, Dr. Walter Brattain, and Dr. William Shockley discovered the transistor effect and developed the first transistor device in December 1947, while the three were members of the technical staff at Bell Laboratories in Murray Hill , NJ . They were awarded the Nobel Prize in physics in 1956. The invention of the transistor had a huge impact on the electronics industry. Amateur Band Radios (Handhelds or Handy-Talkies), Portable Broadcast Receivers (both radio and television) plus Business Band Radios could now be manufactured into smaller packages. Manufacturers like Yaesu, Icom and Kenwood (Amateur Band Radios) Motorola and Uniden (Business Band Radios) plus RCA, Admiral and Emerson (Broadcast Band Radio and Television Receiver’s) and other manufactures to numerous to mention here, could now cheaply manufacture their electronics. There was a revolution in electronic design and manufacturers had a heyday. Although, new Amateur Band, Business Band and Broadcast Band receiver designs using transistors were develop. 

The Superheterodyne system of radio receiver design was and still is used. A better radio receiver system has not been developed, because a Superheterodyne Receiver is still the best and easiest way to construct a receiver, and this design has been in use since the early 1930’s. We have come a long way since the invention of radio (Nikola Tesla) and the invention of the television (Philo T. Farnsworth). Credit is not given to these inventors because others who have come after them improved their designs and exploited them for monetary gain. 

The invention of the transistor also had a very big impact on computers. Charles Babbage invented the computer and called it an Analytical Engine in 1830 but it was crude and had very little significant worth with the masses at that time other then for mathematical use by the inventor. The first computers were used during WWII by the U.S. Military for munitions calculations, but were not commercially available until they were perfected at the Aberdeen Proving Grounds, Maryland , in the late1940’s. Later, they were installed in Colleges and Universities so those students could get hands-on experience. Pratt Institute in NYC had a computer that was manufactured with Vacuum Tubes in the late 1950’s it was for the use of its students and filled two rooms of electronics. The computers manufactured in the 50’s were big, clunky and they took up lots of space because they were designed with Vacuum Tubes. With the invention of the transistor they became smaller, lighter, and were able to perform more instructions faster. ENIAC, the first Digital computer available commercially (Analog Computers were in wide use at that time) and later UNIVAC was used by financial institutions until IBM introduced their computer the IBM 360 and the two companies were in competition. IBM soon became the dominant manufacturer and received many installation contracts. Although, the IBM 360 was fast for its time, it was manufactured using discrete (individual) transistors. When IBM introduced the 370 in 1969, it was manufactured using TTL Integrated circuits. The IBM 370 was smaller and faster then its predecessor the IBM 360. 

TTL (Transistor-Transistor Logic) has many transistors on a single substrate hence called an “Integrated Circuit” or IC. An Integrated Circuit made up of hundreds of transistors is called Small Scale Integration (SSI). But even thousands of transistors can be put on a single substrate called Medium Scale Integration (MSI) and even hundreds of thousands of transistors can be placed on a single substrate called Large Scale Integration (LSI). The IBM computers of that era, even though they were improved compared to previous years, used TTL Integrated Circuit Chips. These computers required very large Current Power Supplies and programmers had to use JCL (Job Control Language) Punch Cards for every instruction. Computers were still evolving to even smaller sizes. The Minicomputer was the next generation of computer. Companies like (DEC) Digital Equipment Company and CD (Control Data Corporation) introduced their versions. The DEC PDP 11 and the CD 1117 were two Minicomputers in direct competition. The Minicomputer used Magnetic Core Memories, but they were relatively slow because of the need to access their many slow memory cores. However, they were still faster then their predecessors. The Minicomputer was the mainstay of computers for over 10 years until the Single Integrated Circuit (chip) computers were created. Semiconductor manufacturers manufactured many computer IC chips. The 1802-RCA, F8- Fairchild, Z80-Zilog, 6800-Motorola, 4004-Intel plus other manufactures too numerous to list. Although, many chip manufacturers soon discontinued manufacturing computer chips the main stays were Intel and Motorola Corporation. These companies are the two top computer chip manufactures today. 

A complete computer called “Microprocessor” could now be put on a single substrate (chip) using CMOS (Complementary Metal Oxide Semiconductors). The predecessor to the Pentium was initially the 4004 a 4-bit computer introduced in 1970, followed by the 4040 also a 4-bit computer with enhancements over the 4004 and later the 8008 an 8-bit computer. Still later the 8080 also an 8-bit computer with enhancements over the 8008, all manufactured by the Intel Corporation. A 4-bit computer is called a 4-bit computer even though its address bus is 8-bits long because the computer’s data word length is 4 bits long and that what made up the size of the computer at that time. A 4-bit computer has only 4 data lines, which makes for a small instruction set. With 4 bits for the instruction word the computer can only have a maximum of 16 instructions 2 raised to 4^th power = 16 and with an address bus of 8 bits you can only address 256 memory locations. 2 raised to the 8^th power = 256. Raising 2 to the power of the number of bits that are used is called Binary the mathematics of computers. 

The 8080’s were designed into the TRS-80, Scientific Atlanta, IMSI and Commodore Computers plus many, many others. Although, these computers were sold by retail chain stores like Radio Shack, Computerland and the Byte Shop they did not sell as expected. Computerland and the Byte Shops closed due to poor sales. However, Radio Shack had the Arrow line of electronic components plus The Tandy Leather Company and their stores survived. Motorola introduced their single chip computer an 8-bit computer the 6800 very soon after the Intel’s 4-bit computer introduction and both companies were in competition. Motorola chips could be found in the Apple Macs, and Intel chips could be found in the IBM PCs. Initially the original 4-bit computer introduced by Intel used Machine and Assembly language. 

The 8-bit computers were able to use the BASIC Programming language because of the increased instruction word length of 8 bits, even though both are now much enhanced computers, using C++ as their main language for programming. The Intel Pentiums or IBM computers are more abundant. The Apple Mac is a very good computer. However, because of the dearth of available programs for the Apple Mac it hasn’t seen as widespread use as has the Intel Pentium.  The majority of Apple Macs are used mostly by Musicians and Artists, as there is an abundance of music and art software for them.  Almost any version of software for the Pentium can also be obtained for the Apple Mac. The Pentium’s and Apple Macs have developed into today’s advanced computers based on the initial use of the first microcomputers (4004 and 6800) 

One could only have a computer in the early 1970’s if they built them from available parts. An 8-bit computer can have a maximum of 256 instructions, 2 raised to the 8^th power. Although, an 8-bit computer can have 256 instructions, however, they never contained that many and only contained 76 instructions. With an increased instruction word length and 76 instructions it had more power and control compared to the 16 instructions 4-bit computers had. And with 8 data bits in the instruction word one could use the BASIC computer language, which is easier to use instead of a higher level language such as Machine language or Assembly language. 

An 8-bit computer has 16 address bits, which means it can address 2 raised to the16th power or 65,536 memory locations directly. Amateur Radios, Business Band Radios and Broadcast Band Receiver’s and Transmitter’s now incorporate CMOS chips and transistors into their designs and can use a higher band of frequencies for reception and transmission. They also use GaAs (Gallium Arsenic) FETs in their designs.  The elements of Gallium and Arsenic form a compound called Gallium Arsenide that is used in the manufacturer of (semiconductors) FETs that have a very high frequency response and low noise. The GaAs FET is used in design of Microwave and UHF/VHF receivers and transmitters.

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