pes of companies of which all have their own family of processors. Since the individual processors in thefamilies were developed over a fairly long period of time, it is hard to distinguish which processors were introduced in order. This paper will mention the families ofprocessors in no particular order. The first microprocessor that will be discussed is the family of microprocessors called the 9900 series manufactured by TexasInstruments during the mid-70s and was developed from the architecture of the 900 minicomputer series (Titus, 178). There were five dif- ferent actualmicroprocessors that were designed in this family, they were the TMS9900, TMS9980A, TMS9981, TMS9985, and the TMS9940. The TMS9900 was the firstof these microprocessors so the next four of the microprocessors where simply variations of the TMS9900 (Titus, 178). The 9900 series microprocessors runs with64K memory and besides the fact that the 9900 is a 16-bit microprocessor, only 15 of the address memory circuits are in use (Titus, 179). The 16th address is usedfor the computer to distinguish between word and data functions (Titus, 179. The 9900 series microprocessors runs from 300 nanoseconds to 500 ns from 2MHz to3.3MHz and even some variations of the original microprocessor where made to go up to 4MHz (Avtar, 115). The next microprocessor that will be discussed is theLSI-11 which was pro- duced from the structural plans of the PDP-11 minicomputer family. There are three microprocessors in the LSI-11 family they are theLSI-11, LSI-11/2, and the much im- proved over the others is the LSI-11/32 (Titus, 131). The big difference between the LSI-11 family of microprocessors andother similar microprocessors of its kind is they have the instruction codes of a microcomputer but since the LSI-11 microprocessor originated from the PDP-11family it is a multi-microprocessor (Avtar, 207). The fact that the LSI-11 microprocessor is a multi-microprocessor means that many other mi...
