Isa Slots Definicion
Whether you need a Windows 98 computer with multiple ISA slots, or a modern Windows 10 PC with ISA, we can help. Please feel free to contact us or send us an email at email protected and we can work together on a solution for your legacy hardware requirements. Last Modified Date: November 30, 2020 A slotted screwdriver is a tool used to apply torque to screws using a flat tip. Torque is the pressure applied when a device is turned clockwise or counterclockwise into place. This type of tool is designed to fit into slotted screw heads, which feature a single diveted flat impression on top of the screw. Looking for online definition of ISA or what ISA stands for? ISA is listed in the World's largest and most authoritative dictionary database of abbreviations and acronyms The Free Dictionary.
Also found in: Dictionary, Thesaurus, Medical, Encyclopedia, Wikipedia.| Acronym | Definition |
|---|---|
| ISA | Industry Standard Architecture (PC slot type) |
| ISA | Internet Security and Acceleration (Microsoft firewall and cache server) |
| ISA | Is A (entity hierarchy in extended entity-relationship data model) |
| ISA | Instruction Set Architecture |
| ISA | Individual Savings Account (UK) |
| ISA | Internal Security Act |
| ISA | International Studies Association |
| ISA | Independent Safeguarding Authority (UK) |
| ISA | International Student Association |
| ISA | Instrumentation, Systems, and Automation Society (now International Society of Automation) |
| ISA | Isaiah |
| ISA | International Society of Automation (est. 1945) |
| ISA | International Sociological Association |
| ISA | International Society of Arboriculture |
| ISA | International Standard on Auditing |
| ISA | Indian Student Association |
| ISA | Intelligent Systems and Applications (workshop) |
| ISA | India Semiconductor Association (Bangalore, India) |
| ISA | International Students Association |
| ISA | Instrument Society of America (now International Society for Measurement and Control) |
| ISA | International Searching Authority |
| ISA | Instituto Socioambiental (Portuguese: Socio-Environmental Institute; Brazil) |
| ISA | Intelligent Speed Adaptation |
| ISA | International Studies Abroad (various locations) |
| ISA | Information Security Administration |
| ISA | International Society of Appraisers |
| ISA | International Sign Association (formerly National Electric Sign Association) |
| ISA | Intelligence Services Act (various locations) |
| ISA | Internal Security Assessor (Payment Card Industry Security Standards Council) |
| ISA | Independent Subspace Analysis |
| ISA | Interplanetary Strategic Alliance (Killzone) |
| ISA | International Society of Andrology |
| ISA | International Seabed Authority |
| ISA | Inshaallah |
| ISA | Institute for Social Anthropology (various locations) |
| ISA | Institute for Study Abroad |
| ISA | Israel Security Agency |
| ISA | International Shipping Agency (various locations) |
| ISA | International Songwriters Association (UK) |
| ISA | Impervious Surface Area |
| ISA | International Schools Association |
| ISA | Iran Sanctions Act of 1996 |
| ISA | International Symbol of Access (wheelchair standard; International Commission on Technology and Accessibility) |
| ISA | Interconnection Security Agreement (US NIST) |
| ISA | Invest in Sweden Agency |
| ISA | Insurance Services of America (Christian insurance organization) |
| ISA | Internet Security and Acceleration |
| ISA | Internet Service Api |
| ISA | Industry Standard Architecture |
| ISA | Internet Server Application |
| ISA | Internet Security Association |
| ISA | Information Security and Assurance |
| ISA | Integrated Starter Alternator |
| ISA | Itanium Solutions Alliance |
| ISA | Internet Services Administrator |
| ISA | Informix Server Administrator |
| ISA | Individual Savings Account |
| ISA | Independent Stations Algorithm |
| ISA | Incline Start Assist |
| ISA | IBM Support Assistant |
| ISA | Internet Security Appliance (software) |
| ISA | Irish Sailing Association |
| ISA | Industry Specific Application |
| ISA | Infectious Salmon Anaemia |
| ISA | International Standard Atmosphere |
| ISA | International Student Advisory (various locations) |
| ISA | International Security Affairs |
| ISA | Independent School Association (various locations) |
| ISA | International Society for Measurement and Control |
| ISA | Israel Securities Authority |
| ISA | Information Security and Assurance (international conference) |
| ISA | Industry Sector Analysis |
| ISA | Iowa Soybean Association |
| ISA | International Stuttering Association |
| ISA | Intrinsic Sympathomimetic Activity |
| ISA | Indian Squash Academy |
| ISA | Independent Safety Assessment |
| ISA | Intelligence Support Activity (US Army) |
| ISA | International Society of Arborists |
| ISA | Interactive Services Association |
| ISA | Itanium Solutions Alliance (microprocessors) |
| ISA | Israel Space Agency |
| ISA | Information Security Architecture |
| ISA | Interstellar Alliance (Babylon5) |
| ISA | International Stillbirth Alliance (Chicago, Illinois, USA) |
| ISA | International Space Agency (Star Trek) |
| ISA | Instituto Superior de Agricultura (Dominican Republic) |
| ISA | Instrumentation Society of America (Research Triangle Park, North Carolina) |
| ISA | Investment Savings Account |
| ISA | Investment Savings Account ( UK tax-free investment account) |
| ISA | Institut Supérieur d'Agriculture de Lille (French: Lille Higher Institute of Agriculture; Lille, France) |
| ISA | Information System Architecture |
| ISA | Integrated Services Architecture |
| ISA | Integrated Starter-Alternator |
| ISA | Independent Safety Auditor (various organizations) |
| ISA | Importer Self-Assessment Program |
| ISA | International Scientific Association |
| ISA | Internal Systems Administrator |
| ISA | Indian Statistical Association (est. 1960) |
| ISA | Internet Society of Australia (est. 1992) |
| ISA | Indian Society of Agricultural Engineers |
| ISA | International Service Assessment |
| ISA | Interfaith Stewardship Alliance |
| ISA | Incest Survivors Anonymous |
| ISA | International Spa Association |
| ISA | International Services Advertising |
| ISA | Internet Service Agentur GmbH (German: Internet Service Agency) |
| ISA | International Strategic Alliance |
| ISA | International School of the Americas (San Antonio, TX) |
| ISA | Interservice Support Agreement |
| ISA | International Society of Women Airline Pilots |
| ISA | Interconexión Eléctrica SA (Colombia) |
| ISA | Integrated Systems Analysts, Inc. |
| ISA | Integrated System Architecture |
| ISA | International Standards Association |
| ISA | Incomplete Stent Apposition |
| ISA | Interim Stowage Assembly (US NASA) |
| ISA | International Silk Association (East Rutherford, NJ) |
| ISA | Inertial Sensor Assembly |
| ISA | Independent Strategic Advisors (Atlanta, GA) |
| ISA | Internet Safety Advocate |
| ISA | Interstage Adapter |
| ISA | Indian Society of Anaesthesiologists |
| ISA | Ionic Strength Adjuster |
| ISA | International Synaesthesia Association |
| ISA | Israel Society of Anesthesiologists |
| ISA | Incident Staging Area (US FEMA) |
| ISA | International Standardization Agreement |
| ISA | In Shaa' Allah (God Willing) |
| ISA | Islamic Shipowners' Association |
| ISA | Integrated Systems and Aerostructures (Northrop Grumman Corp.) |
| ISA | Indirect Speech Act (linguistics) |
| ISA | Ionic Self-Assembly |
| ISA | Integrated Safety Assessment |
| ISA | Irish Stammering Association |
| ISA | Indian Standard Equal/Unequal Angle (steel construction) |
| ISA | Inland Sensitivity Atlas (geographical information system) |
| ISA | Information, Support and Advocacy (various organizations) |
| ISA | International School of Arizona |
| ISA | Ismaili Students Association |
| ISA | Institution of Surveyors, Australia Inc |
| ISA | Indian Set-Aside (grant) |
| ISA | Illinois Society of Anesthesiologists |
| ISA | Integrated Safety Approach |
| ISA | Iterative Sensitivity Adjustment |
| ISA | Integrated Stereo Amplifier |
| ISA | Individual Services Agreement |
| ISA | Inter-Service Agreement |
| ISA | Innovative Signal Analysis |
| ISA | Integrated Services Access |
| ISA | Interim Storage Area |
| ISA | Indiana Society of Anesthesiologists |
| ISA | Integrated Servo Actuator (hydraulic actuators with integrated control unit) |
| ISA | Indiana Sheep Association (Greenwood, IN) |
| ISA | Interviewing Service of America, Inc. (Van Nuys, CA) |
| ISA | Iso-Saccharinic Acid |
| ISA | Installation Support Agreement |
| ISA | Idaho Sheriffs' Association |
| ISA | Interrupt Storage Area |
| ISA | In-Depth Safety Analysis |
| ISA | Information Science Associates |
| ISA | Incident Surprise Anomaly Report |
| ISA | Installation Supply Activity |
| ISA | Inductee Special Assignment |
| ISA | Intermediate Staging Area |
| ISA | Indicator-Based Stall Avoidance |
| ISA | Intelligent Search Assistant |
| ISA | Information and Services Acquisition |
| ISA | Information Services Analysis |
| ISA | Integrated Support Area |
| ISA | Integrated Support Activity |
| ISA | Information Society Assessment (EU) |
| ISA | Installation Support Activity |
| ISA | Institute for Application-Oriented Software and Systems (GMD, Germany) |
| ISA | International Subscription Agencies Pty Ltd (now RoweCom Australia Pty Ltd) |
| ISA | Ignition & Separation Assembly |
| ISA | Imaging Sensor Autoprocessor |
| ISA | Installation Supply Account |
| ISA | Intensive Support Allocations |
| ISA | Inprocess Sample Analysis |
| ISA | Iterative Statistics Algorithm |
| ISA | Imaging/Imagery Sensor Autoprocessor |
| ISA | Ideal Survey Attributes (relate to key success factors in instrument development & quality improvement) |
| ISA | Instructor of Small Arms |
| ISA | IETM Support Activity |
| ISA | IRS System Architecture |
| ISA | International Shipmasters Association of the Great Lakes |
| ISA | Information Superiority Assessment |
| ISA | Instantaneous Selection Algorithm |
| ISA | Insurance Service Account (Northwestern Mutual; Milwaukee, WI) |
| ISA | Installation and Service Activity |
| ISA | Identifier Splitting Algorithm |
| ISA | International Systems Associates, Ltd. |
| ISA | Intrasystem Analysis |
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The Instruction Set Architecture (ISA) is the part of the processorthat is visible to the programmer or compiler writer. The ISA serves asthe boundary between software and hardware. We will briefly describe theinstruction sets found in many of the microprocessors used today. The ISAof a processor can be described using 5 catagories:
- Operand Storage in the CPU
- Where are the operands kept other than in memory?
- Number of explicit named operands
- How many operands are named in a typical instruction.
- Operand location
- Can any ALU instruction operand be located in memory? Or must all operandsbe kept internaly in the CPU?
- Operations
- What operations are provided in the ISA.
- Type and size of operands
- What is the type and size of each operand and how is it specified?
Of all the above the most distinguishing factor is the first.
The 3 most common types of ISAs are:
- Stack - The operands are implicitly on top of the stack.
- Accumulator - One operand is implicitly the accumulator.
- General Purpose Register (GPR) - All operands are explicitelymentioned, they are either registers or memory locations.
Lets look at the assembly code of
in all 3 architectures:
| Stack | Accumulator | GPR |
| PUSH A | LOAD A | LOAD R1,A |
| PUSH B | ADD B | ADD R1,B |
| ADD | STORE C | STORE R1,C |
| POP C | - | - |
Not all processors can be neatly tagged into one of the above catagories.The i8086 has many instructions that use implicit operands although ithas a general register set. The i8051 is another example, it has 4 banksof GPRs but most instructions must have the A register as one of its operands.
What are the advantages and disadvantages of each of these approachs?
Stack
Advantages: Simple Model of expression evaluation (reverse polish).Short instructions.
Disadvantages: A stack can't be randomly accessed This makes ithard to generate eficient code. The stack itself is accessed every operationand becomes a bottleneck.
Isa Slots Definicion Y
Accumulator
Advantages: Short instructions.
Disadvantages: The accumulator is only temporary storage so memorytraffic is the highest for this approach.
GPR
Advantages: Makes code generation easy. Data can be stored forlong periods in registers.
Disadvantages: All operands must be named leading to longer instructions.
Earlier CPUs were of the first 2 types but in the last 15 years allCPUs made are GPR processors. The 2 major reasons are that registers arefaster than memory, the more data that can be kept internaly in the CPUthe faster the program wil run. The other reason is that registers areeasier for a compiler to use.
Reduced Instruction Set Computer (RISC)
As we mentioned before most modern CPUs are of the GPR (General PurposeRegister) type. A few examples of such CPUs are the IBM 360, DEC VAX, Intel80x86 and Motorola 68xxx. But while these CPUS were clearly better thanprevious stack and accumulator based CPUs they were still lacking in severalareas:
- Instructions were of varying length from 1 byte to 6-8 bytes. Thiscauses problems with the pre-fetching and pipelining of instructions.
- ALU (Arithmetic Logical Unit) instructions could have operands thatwere memory locations. Because the number of cycles it takes to accessmemory varies so does the whole instruction. This isn't good for compilerwriters, pipelining and multiple issue.
- Most ALU instructions had only 2 operands where one of the operandsis also the destination. This means this operand is destroyed during theoperation or it must be saved before somewhere.
Thus in the early 80's the idea of RISC was introduced. The SPARC projectwas started at Berkeley and the MIPS project at Stanford. RISC stands forReduced Instruction Set Computer. The ISA is composed of instructions thatall have exactly the same size, usualy 32 bits. Thus they can be pre-fetchedand pipelined succesfuly. All ALU instructions have 3 operands which areonly registers. The only memory access is through explicit LOAD/STORE instructions.
Thus C = A + B will be assembled as:
Although it takes 4 instructions we can reuse the values in the registers.
Why is this architecture called RISC? What is Reduced about it?
The answer is that to make all instructions the same length the numberof bits that are used for the opcode is reduced. Thus less instructionsare provided. The instructions that were thrown out are the less importantstring and BCD (binary-coded decimal) operations. In fact, now that memoryaccess is restricted there aren't several kinds of MOV or ADD instructions.Thus the older architecture is called CISC (Complete Instruction Set Computer).RISC architectures are also called LOAD/STORE architectures.
The number of registers in RISC is usualy 32 or more. The first RISCCPU the MIPS 2000 has 32 GPRs as opposed to 16 in the 68xxx architectureand 8 in the 80x86 architecture. The only disadvantage of RISC is its codesize. Usualy more instructions are needed and there is a waste in shortinstructions (POP, PUSH).
So why are there still CISC CPUs being developed? Why is Intel spendingtime and money to manufacture the Pentium II and the Pentium III?
The answer is simple, backward compatibility. The IBM compatible PC isthe most common computer in the world. Intel wanted a CPU that would runall the applications that are in the hands of more than 100 million users.On the other hand Motorola which builds the 68xxx series which was usedin the Macintosh made the transition and together with IBM and Apple builtthe Power PC (PPC) a RISC CPU which is installed in the new Power Macs.As of now Intel and the PC manufacturers are making more money but withMicrosoft playing in the RISC field as well (Windows NT runs on Compaq'sAlpha) and with the promise of Java the future of CISC isn't clear at all.
An important lesson that can be learnt here is that superior technologyis a factor in the computer industry, but so are marketing and price aswell (if not more).
References For Further Reading
Slot Isa Definicion
Philip Koopman Stack Computer Web pages