优秀课件笔记english-writing专业英语写作3

抽象随意型为主(AR)
. 我几乎总是:
. ------喜欢作决定之前与他人核定一下
. ------对他人的感觉十分敏感
. ------与他人能很好地共事
. ------不受杂乱环境的干扰
. ------有疑惑时会征求他人的意见
. 总共----项、
. 具体随意型为主(CR)
. 我几乎总是:
. ------解决问题有自己的主见
. ------办事不假思索
. ------喜欢跟自己节奏一致的人共事
. ------喜欢环境不断变化
. ------只了解需要了解的东西
. 总共----项
. 具体有序型为主(CS)
. 关键词:事实
. 一切从实际情况出发考虑
. 全面进行考量
. 从抽象观点产生具体结果
. 按时完成工作
. 抽象有序型为主(AS)
. 关键词:根本原则
. 作决定前收集数据
. 分析种种想法
. 研究
. 提供逻辑顺序
. 用事实证明或反驳理论设想
. 分析达到目的的种种途径
. 抽象有序型为主(AS)
. 关键词:根本原则
. 作决定前收集数据
. 分析种种想法
. 研究
. 提供逻辑顺序
. 用事实证明或反驳理论设想
. 分析达到目的的种种途径
. 具体随意型为主(CR)
. 关键词:强烈的理由
. 激励他人采取行动
. 权衡多种选择机会与解决的办法
. 提供新颖,富有创造型的意见
. 虚构未来
. 经常改变行事方式
. 接受各种类型的人
. 独立思考
. 勇于冒险
. 对他们而言最有意义的是什么?
. 具体有序型为主
. 工作有系统性与条理性
. 十分注意细则
. 有章程可循
. 采用字面解释
. 知道自己的期望值
. 确立行事惯例与方法
. 抽象随意型为主
. 学习个性化
. 有宽泛的,大致的原则
. 尽可能与每个人保持友好关系
. 热情参与他们认定的项目
. 重视高昂的士气
. 用心而非脑子作决定
. 抽象有序型为主
. 采用精确的.研究深入的信息资料
. 通过看而不是做来了解情况
. 运用逻辑推理
. 需要某一领域的专家做老师
. 生活在抽象思维王国
. 行事彻底坚决
. 具体随意型为主
. 运用洞察力及本领来解决问题
. 在一大致而严格具体的时限内行事
. 改善并检测众多解决问题的办法
. 靠生活经验来获取知识
. 身体力行而不相信别人是怎么说的
他们的困难是什么?
. 具体有序型为主
. 分组工作
. 没有具体内容的讨论
. 在一个松散的环境里工作
. 下达的指令不完整或含糊不清
. 运用抽象的观点办事
. 要求发挥你的想象力
. 回答一些既不对又不错的问题
. 抽象有序型为主
. 没时间去全面地解决某一问题
. 重复同样的工作
. 许多细节性的条条框框
. 感性地思考
. 表达他们的情绪
. 运用外交技巧说服他人接受自己的观点
. 不垄断他们感兴趣的话题
. 抽象随意型为主
. 不得不对自己的感情作出解释和证明
. 竞争
. 与不友善的人共事
. 给出准确细则
. 接受善意的批评
. 在某一时间内集中做一件事情
. 具体随意型为主
. 约束与限制
. 正式报告
. 任何事情一旦做完还需要重做
. 日程安排
. 记录具体细则
. 选择唯一答案
. 解释如何得出这一答案
. 没有选择余地
. 学习中他们提些什么问题?
. 具体有序型为主
. 我需要什么事实
. 我怎么做
. 它该像什么样子
. 什么时候到期
. 抽象有序型为主
. 我怎么知道这是真的
. 我们考虑过各种可能性吗?
. 完成这件事我们需要些什么?
. 抽象有序型为主
. 我怎么知道这是真的
. 我们考虑过各种可能性吗?
. 完成这件事我们需要些什么?
Records of Formal Schooling
Transcripts
Necessary Entrance Examination
(Educational Testing Service)
. TOFEL (Test of English as a Foreign
Language)
. GRE (graduate Record Examination)
. GMAT (Graduate Management Admission
Test)
. LAST (Law School Admission Test)
. TSE (Test of Spoken English)
奖学金
. Fellowship:研究奖学金
. Scholarship:奖学金(Full & partial )
. Assistantship:助学金（ＲesearchＡ，Ｔ
eaching Ａ）
. Grant:补助金
. Full & partial tuition waiver: 学费全免或部分
减免
Certificate for the degree of bachelor
. Degree-Certificate NO.6573
July 4,2003
This is to certify that Wei Hong, female, native of
Kunming, Yunnan Province, born on August 18,
1989, specialized in Software in the Computer
Department of this University, has qualified for
graduation. In the past four years she has
satisfactorily finished all the required courses and
got enough credits. Upon the examination and in
conformity with articles of the Regulations
Regarding Academic Degrees in the People’s
Republic of China, she has been admitted to the
degree of Bachelor of Science.
(signed)
President of Yunnan University
Dear Sir,
I write to recommend most warmly one of my best
student, Miss Wang Jing. As I understand, she
wishes to enter your master’s program of Computer
Science in the fall of 2005.
Miss Wang attended the courses “Software Design”
and “Programming Language” instructed by me in
the academic year 2003-2004. her grades in both
courses were the highest in her class. In one
project in the course “Software Design”, she
demonstrated her analytical power and vivid
designing techniques, showing a competence for
independent research. When in class, she often
raised thoughtful questions reflecting her active
imagination and creativity. After class, she read
extensively to enrich her learning in related fields.
This initiative and aggressive attitude is an
obvious asset to her future studies. I expect
greater academic achievements of her.
She has proved herself capable of
advanced knowledge pursuit.
Sincerely yours,
XX, Professor
Department of Computer
Yunnan University
. Dear Mr. Curtis:
. As an experienced computer programmer who
is presently pursuing a master's degree in
electrical engineering at Rensselaer
Polytechnic Institute, I am writing to request
information about possible summer
employment opportunities with HAL. I am
interested in a position that will allow me to
combine the talents I have developed in both
computer programming and electrical
engineering. However, as you can see from
the attached resume, I have extensive
experience in many related fields, and I
always enjoy new challenges.
. I feel that it is important for me to maintain a
practical, real-world perspective while developing
my academic abilities. I am proud of the fact that I
have financed my entire education through
scholarships and summer jobs related to my field of
study.
. This work experience has enhanced my
appreciation for the education I am pursuing. I find
that I learn as much from my summer jobs as I do
from my academic studies. For example, during
the summer of 1986, while working for IBM in Boca
Raton, Florida, I gained a great deal of practical
experience in the field of electronic circuit logic and
driver design.
. When I returned to school in the fall and took
Computer Hardware Design, I found that my
experience with IBM had thoroughly prepared me
for the subject.
Teach Yourself Programming in
Ten Years
. Why is everyone in such a rush?
. Walk into any bookstore, and you'll see how to Teach
Yourself Java in 7 Days alongside endless variations
offering to teach Visual Basic, Windows, the Internet,
and so on in a few days or hours. I did the following
power search at Amazon.com:
. pubdate: after 1992 and title: days and
. (title: learn or title: teach yourself)
. and got back 248 hits. The first 78 were computer books
(number 79 was Learn Bengali in 30 days). I replaced
"days" with "hours" and got remarkably similar results:
253 more books, with 77 computer books followed by
Teach Yourself Grammar and Style in 24 Hours at
number 78. Out of the top 200 total, 96% were computer
books.
. The conclusion is that either people are in a big rush
to learn about computers, or that computers are
somehow fabulously easier to learn than anything else.
There are no books on how to learn Beethoven, or
Quantum Physics, or even Dog Grooming in a few
days.
. Let's analyze what a title like Learn Pascal in Three
Days could mean:
. Learn:
In 3 days you won't have time to write several
significant programs, and learn from your successes
and failures with them. You won't have time to work
with an experienced programmer and understand
what it is like to live in that environment. In short, you
won't have time to learn much. So they can only be
talking about a superficial familiarity, not a deep
understanding. As Alexander Pope said, a little
learning is a dangerous thing.
. Pascal:
In 3 days you might be able to learn the
syntax of Pascal (if you already knew a similar
language), but you couldn't learn much about how
to use the syntax. In short, if you were, say, a Basic
programmer, you could learn to write programs in
the style of Basic using Pascal syntax, but you
couldn't learn what Pascal is actually good (and
bad) for. So what's the point? Alan Perlis once said:
"A language that doesn't affect the way you think
about programming, is not worth knowing". One
possible point is that you have to learn a tiny bit of
Pascal (or more likely, something like Visual Basic
or JavaScript) because you need to interface with
an existing tool to accomplish a specific task. But
then you're not learning how to program; you're
learning to accomplish that task.
. in Three Days:
Unfortunately, this is not enough, as the next
section shows.
. Teach Yourself Programming in Ten Years
. Researchers (Hayes, Bloom) have shown it takes about ten
years to develop expertise in any of a wide variety of areas,
including chess playing, music composition, painting, piano
playing, swimming, tennis, and research in neuropsychology
and topology. There appear to be no real shortcuts: even
Mozart, who was a musical prodigy at age 4, took 13 more
years before he began to produce world-class music. In another
genre, the Beatles seemed to burst onto the scene with a string
of #1 hits and an appearance on the Ed Sullivan show in 1964.
But they had been playing small clubs in Liverpool and
Hamburg since 1957, and while they had mass appeal early on,
their first great critical success, Sgt. Peppers, was released in
1967. Samuel Johnson thought it took longer than ten years:
"Excellence in any department can be attained only by the labor
of a lifetime; it is not to be purchased at a lesser price." And
Chaucer complained "the lyf so short, the craft so long to lerne."
. Here's my recipe for programming success:
. Get interested in programming, and do some because
it is fun. Make sure that it keeps being enough fun so
that you will be willing to put in ten years.
. Talk to other programmers; read other programs. This
is more important than any book or training course.
. Program. The best kind of learning is learning by
doing. To put it more technically, "the maximal level of
performance for individuals in a given domain is not
attained automatically as a function of extended
experience, but the level of performance can be
increased even by highly experienced individuals as a
result of deliberate efforts to improve." and "the most
effective learning requires a well-defined task with an
appropriate difficulty level for the particular individual,
informative feedback, and opportunities for repetition
and corrections of errors." (p. 20-21) The book
Cognition in Practice: Mind, Mathematics, and Culture
in Everyday Life is an interesting reference for this
viewpoint.
. If you want, put in four years at a college (or more at
a graduate school). This will give you access to
some jobs that require credentials, and it will give
you a deeper understanding of the field, but if you
don't enjoy school, you can (with some dedication)
get similar experience on the job. In any case, book
learning alone won't be enough. "Computer science
education cannot make anybody an expert
programmer any more than studying brushes and
pigment can make somebody an expert painter"
says Eric Raymond, author of The New Hacker's
Dictionary. One of the best programmers I ever
hired had only a High School degree; he's produced
a lot of great software, has his own news group, and
through stock options is no doubt much richer than
I'll ever be.
. Work on projects with other programmers. Be
the best programmer on some projects; be the
worst on some others. When you're the best,
you get to test your abilities to lead a project,
and to inspire others with your vision. When
you're the worst, you learn what the masters
do, and you learn what they don't like to do
(because they make you do it for them).
. Work on projects after other programmers. Be
involved in understanding a program written
by someone else. See what it takes to
understand and fix it when the original
programmers are not around. Think about how
to design your programs to make it easier for
those who will maintain it after you.
. Learn at least a half dozen programming languages.
Include one language that supports class abstractions
(like Java or C++), one that supports functional
abstraction (like Lisp or ML), one that supports
syntactic abstraction (like Lisp), one that supports
declarative specifications (like Prolog or C++
templates), one that supports coroutines (like Icon or
Scheme), and one that supports parallelism (like Sisal).
. Remember that there is a "computer" in "computer
science". Know how long it takes your computer to
execute an instruction, fetch a word from memory
(with and without a cache miss), read consecutive
words from disk, and seek to a new location on disk.
. Get involved in a language standardization effort. It could be
the ANSI C++ committee, or it could be deciding if your local
coding style will have 2 or 4 space indentation levels. Either
way, you learn about what other people like in a language, how
deeply they feel so, and perhaps even a little about why they
feel so.
. Have the good sense to get off the language standardization
effort as quickly as possible.
. With all that in mind, its questionable how far you can get just
by book learning. Before my first child was born, I read all the
How To books, and still felt like a clueless novice. 30 Months
later, when my second child was due, did I go back to the
books for a refresher? No. Instead, I relied on my personal
experience, which turned out to be far more useful and
reassuring to me than the thousands of pages written by
experts.
. Fred Brooks, in his essay No Silver Bullets identified a threepart
plan for finding great software designers:
. Systematically identify top designers as early as
possible.
. Assign a career mentor to be responsible for the
development of the prospect and carefully keep a
career file.
. Provide opportunities for growing designers to
interact and stimulate each other.
. This assumes that some people already have the
qualities necessary for being a great designer; the
job is to properly coax them along. Alan Perlis put it
more succinctly: "Everyone can be taught to sculpt:
Michelangelo would have had to be taught how not
to. So it is with the great programmers".
. So go ahead and buy that Java book; you'll
probably get some use out of it. But you won't
change your life, or your real overall expertise as a
programmer in 24 hours, days, or even months.
. Use your friends. When asked "what operating
system should I use, Windows, Unix, or Mac?",
my answer is usually: "use whatever your
friends use." The advantage you get from
learning from your friends will offset any
intrinsic difference between OS, or between
programming languages. Also consider your
future friends: the community of programmers
that you will be a part of if you continue. Does
your chosen language have a large growing
community or a small dying one? Are there
books, web sites, and online forums to get
answers from? Do you like the people in those
forums?
. Keep it simple. Programming languages such
as C++ and Java are designed for professional
development by large teams of experienced
programmers who are concerned about the
run-time efficiency of their code. As a result,
these languages have complicated parts
designed for these circumstances. You're
concerned with learning to program. You don't
need that complication. You want a language
that was designed to be easy to learn and
remember by a single new programmer.
真正的程序师
. 正的程序师是不写规格的。拿到程序的使用者，要知
道你已经够幸运了。程序师给你什么，你就感恩地拿
走吧！
　　真正的程序师是不为程序码做注解的。如果程序
难写，当然就很难读懂。既然如此，程序注解还有什
么用？
　　真正的程序师是不写应用程序，因为他们要从裸
机开始写程序。应用程序就留给那些不懂系统程序的
菜鸟去做吧!
　　真正的程序师是不吃法式培根奶蛋卷的，甚至他
连法式培根奶蛋卷用什么做的都搞不清楚。他们吃美
式速食，喝可乐，还有够呛的麻辣川菜。
　　真正的程序师是不画流程图的。流程图毕竟是早
期，较为原始的程序工具。山顶洞人才在乎流程图，
并依据流程图的指示，一步一步照着做.
　　真正的程序师是不读操作手册的。相信操作手册
所载，是新手跟娘儿们的最佳标志。
. 真正的程序师是不会朝九晚五的。如果早上九点
钟你能见到一个正牌的程序师，那是因为他鏖战
整晚迄今未眠。
. 真正的程序师不喜欢编程时用到分工合作的观
念，当然，如果让他当团队的领头，那就例外。
. 真正的程序师喜欢兼卖爆米花。一般的程序师用
微波炉来爆，真正的程序师会善用中央处理器运
转时所散发的热量。他们甚至可以根据米花爆裂
的速度，告诉你现在系统运行的是那一个工作。
.
Public integer SQRT(real x)
Y: = 0
(y+1)
2
<=x y: = y+1
. PLAZA DE ESPANA
SEVILLE, SPAIN
11:00 A.M.
. It is said that in death, all things become clear; Ensei
Tankado now knew it was true. As he clutched his
chest and fell to the ground in pain, he realize the
horror of his mistake. People appeared, hovering over
him, trying to help. But Tankado did not want help - it
was too late for that. Trembling, he raised his left hand
and held his fingers outward. Look at my hand! The
faces around him stared, but he could tell they did not
understand. On his finger was an engaved golden ring.
For an instant, the markings glimmered in the
Andalusian sun. Ensei Tankado knew it was the last
light he would ever see.
. "Hello?"
"Susan, it's David. Did I wake you?"
She smiled, rolling over in bed. "I was just dreaming of
you. Come over and play."
He laughed. "It's still dark out."
"Mmm." She moaned sensuously. "Then definitely
come over and play. We can sleep in before we head
north."
David let out a frustrated sigh. "That's why I'm calling.
It's about our trip. I've got to postpone."
Susan was suddenly wide awake. "What!"
. Susan's Volvo sedan rolled to a stop in the shadow of
the ten-foot-high, barbed Cyclone fence. A young
guard placed his hand on the roof.
"ID, please."
Susan obliged and settled in for the usual half-minute
wait. The officer ran her card through a computerized
scanner. Finally he looked up. "Thank you, Ms.
Fletcher." He gave an imperceptible sign, and the gate
swung open.
Half a mile ahead Susan repeated the entire
procedure at an equally imposing electrified fence.
Come on, guys... I've been through here a million
times.
. As she approached the final checkpoint, a stocky
sentry with two attack dogs and a machine gun
glanced down at her license plate and waved her
through. She followed Caine Road for another 250
yards and pulled into Employee Lot C.
Unbelievable, she thought. Twenty-six thousand
employees and a twelve-billion-dollar budget; you'd
think they could make it through the weekend
without me. Susan gunned the car into her
reserved spot and killed the engine. After crossing
the landscaped terrace and entering the main
building, she cleared two more internal checkpoints
and finally arrived at the windowless tunnel that led
to the new wing. A voice-scan booth blocked her
entry.
. NATIONAL SECURITY AGENCY (NSA)
CRYPTO FACILITY
AUTHORIZED PERSONNEL ONLY
. The armed guard looked up. "Afternoon, Ms.
Fletcher."
Susan smiled tiredly. "Hi, John."
"Didn't expect you today."
"Yeah, me neither." She leaned toward the parabloic
microphone. "Susan Fletcher," she stated clearly. The
computer instantly confirmed the frequency
concentrations in her voice, and the gate clicked open.
She stepped through.

Different Folks, Different
keystrokes
. A small but picky group of the computer-using
population has always hated the key boards
supplied with the systems enough to trash
them and spend good money on a replacement.
Some folks complain that their keyboards are
too “clicky”
. , others, too “mushy”. Now the issue has moved
beyond connoisseurship. Many people, their
wrists and fingers aching from repetitive stress
injuries are looking at so-called ergonomic
keyboards, claimed to be more comfortable.
The computer as a communication
device
. In a few years, men will be able to communicate
more effectively through a machine than face to face.
. That is a rather startling thing to say, but it is our
conclusion. As if in confirmation of it, we participated
a few weeks ago in a technical meeting held through
a computer. In two days, the group accomplished
with the aid of a computer what normally might have
taken a week.
. We shall talk more about the mechanics of the
meeting later; it is sufficient to note here that we were
all in the same room. But for all the communicating
we did directly across that room, we could have been
thousands of miles apart and communicated just as
effectively-as people-over the distance.
. Our emphasis on people is deliberate. A
communications engineer thinks of communicating as
transferring information from one point to another in
. codes and signals. But to communicate is more than
to send and to receive.
. Do two tape recorders communicate when they play to
each other and record from each other? Not really-not
in our sense. We believe that communicators have to
do something nontrivial with the information they send
and receive.
. And we believe that we are entering a technological
age in which we will be able to interact with the
richness of living information—not merely in the
passive way that we have become accustomed to
using books and libraries, but as active participants in
an ongoing process, bringing something to it through
. our interaction with it, and not simply receiving
something from it by our connection to it.
. Still there is not much direct interaction with the
airline information service; the tape recording is
not changed by the customer’s call.
. We want to emphasize something beyond its
one-way transfer: the increasing significance of
the jointly constructive, the mutually reinforcing
aspect of communication—the part that
transcends “now we both know a fact that
. only one of us knew before.”
. When minds interact, new ideas emerge. We
want to talk about the creative aspect of
communication.
. Creative, interactive communication requires a plastic
or moldable medium that can be modeled, a dynamic
medium in which premises will flow into consequences,
and above all a common medium that can be
contributed to and experimented with by all.
. Such a medium is at hand—the programmed digital
computer. Its presence can change the nature and
value of communication even more profoundly
. than did the printing press and the picture tube, for, as
we shall show, a well-programmed computer can
provide direct access both to informational
. resources and to the processes for making use of the
resources,
The project meeting as a model

. When mental models are dissimilar, the
achievement of communication might be
signaled by changes in the structure
. of one of the models, or both of them.
Processor Products -- Final Report of
SPREAD Task Group, December 28, 1961
. This report recommends a new family of
compatible processors for the IBM product
line. A summary of the major points follows.
1. IBM customers' needs for general-purpose
processors can be most profitably met by a
single compatible [Top of Page 7] family
extending from the smallest stored-program
core-memory machine to the machine for
customers growing beyond the 7094 and
7030.
. There are processor needs above and below
this range; it is not yet evident that these
can be compatible with the new processor
family. 2. Justification for the compatible
family has been established with respect to
marketing. It is clearly advantageous to
development and manufacturing.
Competitors appear to be relying heavily on
common programming languages to ...
Introduction
A. Mission and Objectives
. 1. The SPREAD activity was initiated to
establish an overall IBM plan for data
processor products. The plan is to encompass
all stored- program processor developments in
IBM, is to extend to 1970, and must consider
the following factors.
. a. Solid logic technology (SLT), which
promises improved cost/performance and
reliability.
. b. New market demands for systems capable
of multiterminal, on-line, real-time,
multiprogramming operation.
. c. The explosive growth in applied programming
demanded by a larger number of dissimilar
systems.
. d. The 15- 20 engineering groups generating
processor products and the need for the
establishment of consistency -- i.e., an IBM
"image" in the processor field.
. e. The need to resolve the interactions
between present and new processor products
across divisional and World Trade lines.
. 2. Faced with these present problems, the
SPREAD task force set as its objectives:
. a. The definition of a new line of processor
products. b. The establishment of logical design,
engineering, and applied programming ground
rules, within which a processor product line
consistent across divisions and World Trade
must be defined. c. The creation of a plan for
the introduction of these new products that will
optimize the conflicting demands of: (1) Market
need. (2) Impact on present installed
processors. d. The initiation of an appropriate
management measurement and control
mechanism to assure the implementation of the
SPREAD product concepts.
THE IBM 360 ARCHITECTURE
T H E I B M 3 6 0 A R C H I T E C T U R E
. In mid-April 1964 IBM introduced the 360 family
of
computers.
. The beginning of modern computer architecture can
be dated from then.
. The profound intellectual innovation was the strict
separation of architecture from implementation
. The IBM, at that time, had about 6 or 7 separate and
incompatible product lines (this is in contrast to IBM's
line of punched card equipment which was one
consistent sequence of equipment):
. Some of the determining characteristics of these
"lines" were small vs. large computers, business vs.
scientific applications, history/technology,
organizational; e.g., Endicott vs. Poughkeepsie Labs
vs. San Jose Labs vs. World Trand (England); all
were independently designing computers.
. Lost economies of scale, particularly in peripherals, research
and development, ....
. Decided they would have one product line that was upward and
downward
compatible (Upward compatible was common, you
have a program for one computer, then the next one up would
be designed to include all the instructions and other capabilities
of the original plus "some"; you just wouldn't use the "plus
some." But going the other way was more difficult. How could
you run an application that was programmed on a powerful
computer with a rich instruction set on a small computer with a
small set? It was not clear that this could be accomplished.
. An idea of MV Wilke's (through IBM World Trade) from the
fifties provided the answer. The solution was
microprogramming
m i c r o p r o g r a m i n g
. The idea was to build the architecture
around micro instructions. Then arbitrarily complicated
instructions (at the programmer level) could be emulated by
microprograms that were stored non-volatilely in read only
memories (ROM). Firmware
F i r m w a r e
. Then for the small computers, the
instructions not available in hardware could be emulated in
firmware.
. April 7, 1964 IBM announced the IBM 360 family:
Models 30, 40, 50, 60, 62, 70 spanning a performance
range of about 25 to 1.
. The new family was incompatible with all the previous
lines (although emulators were implemented for most
of them, again based on microprogramming)
. Ultimately, the family evolved into the IBM 370
(announced in 1970), IBM 303x (beginning in 1977),
IBM 43XX (beginning in 1979), and IBM 308X (starting
in 1981) all with 360 architecture and resulting in a
performance range of thousands to one. 309X, (3090-
400 over 2000 times faster than the System 360
Model 30.
. Important firsts, integrated scientific and business,
upward and downward
compatibility, clear
demarcation between architecture and implementation,
multiprogramming, microcoded emulation.
. The IBM was one of the earliest realizations of an
instruction set architecture. It was a CISC (Complex
Instruction Set Computing) architecture. The trend
towards CISC was promoted by:
. The desire to maintain upward compatibility.
. The desire to reduce the semantic gap between
natural or high level computer language and machine
language by adding instructions closer to those used
by programmers. (Because of the higher semantic
content these were more complex; moreover, they
often did not match exactlly what programmers
wanted and were underutilized)
. The desire to improve performance by the movement
of functions from software to microcode to hardware
without consideration of impact on implementation
. The availability of tools and methodologies for
designing more complex architectures; e.g., CAD and
microprogramming support programs.
. For years, the IBM architectural approach dominated.
PC's copied it as
. For years, the IBM architectural approach dominated.
PC's copied it as well as they could. As new
computers were developed they had to be upward
compatible with old, so there was an accretion of
instructions, both hardwired, and in firmware. "We
have increased the number of instructions by almost
50 percent, ...." Andris Padegs (re 360 architecture in
1988)
. The compilers were not too good, so the idea became
to build a lot of high level features into the instruction
set. So special, and complex "block" commands, and
call routines were built into the instruction set. This
was the CISC or Complex Instruction Set Computer
architecture. Most mainframes today are still of this
type. The Intel microprocessors today are mostly
CISC, although the Pentium less so (hybrid).