Virtual CD-ROM is a simulation (CD-ROM) work of the tool software, you can generate and your computer installed on the CD-ROM drive kinetic energy exactly the same as the virtual CD-ROM drive, the general CD-ROM drive can do virtual CD-ROM drive can do the same thing, the principle of this work is to virtualize a virtual CD-ROM drive or a number of virtual CD-ROM drive will be the CD-ROM application, the image stored on the hard disk, and generate a virtual CD-ROM drive image file, then you can Windows 95/98/NT will be put into this image file to use. Virtual CD-ROM image file, then you can Windows95/98/NT will be this image file into the virtual CD-ROM drive to use, so when you want to start this application later, do not have to put the CD-ROM in the CD-ROM drive, there is no need to wait for the slow start of the CD-ROM, just need to insert the icon on the tap, the virtual CD-ROM is immediately loaded into the virtual CD-ROM drive to run, fast and convenient.
Features and uses of virtual CD-ROM drive
Virtual CD-ROM drive has a lot of features that a normal CD-ROM drive can't achieve, such as running without CD-ROM, even if you don't use a CD-ROM drive, executing multiple CD-ROM software at the same time, fast processing power, easy to carry and so on. Virtual CD-ROM drives have the following features and uses:
(1). High-speed CD-ROM
Virtual CD-ROM drive running directly on the hard disk, the speed of up to 200X; virtual CD-ROM drive CD-ROM drive response speed is very fast, playback of video and image files smooth and non-stop. The average hard drive transfer speed is about 10-15MB/S, which translates to an optical drive transfer speed (150K/S) equal to 100X. Today's motherboards are mostly integrated with Ultra DMA hard drive controllers, which deliver transfer speeds of up to 33M/S (220X)
(2). The best companion for laptops
Virtual CD-ROM drive can solve the problems of laptops without CD-ROM drive, too slow, not easy to carry, CD-ROM drive power consumption, etc.; CD-ROM image can be copied from other computers or the network.
(3). The best choice for MO
The CD-ROM (virtual CD-ROM) generated by the virtual CD-ROM drive can be stored in the MO disk, and if you carry it with you, then the MO disk will become the "CD-ROM MO", and the MO CD-ROM drive will be in one place, which is the best choice for MO.
(4). Copy CD
Virtual CD-ROM drive copying CD-ROM only produces a corresponding virtual CD-ROM file, so it is very easy to manage; not hundreds of CD-ROM files copied to the hard disk, this method is not necessarily able to run correctly, because a lot of CD-ROM software will be required to run in the CD-ROM drive, and deletion of the management is a problem; virtual CD-ROM drive is a complete solution to these problems.
(5). Run multiple CD-ROMs
Virtual CD-ROM drives can run several different CD-ROM applications at the same time. For example, we can watch Encyclopedia Britannica on one CD-ROM drive, install Kingsoft 2000 on another, and listen to CDs on a real CD-ROM drive. We can't do that on one optical drive in any way.
(6). Compression
Virtual CD-ROM drives generally use professional compression and instant decompression algorithms for some uncompressed files, the compression rate of up to 50% or more; run-time automatic instant decompression, image playback effect will not be distorted.
(7). CD-ROM Tower
Virtual CD-ROM drive can completely replace the expensive CD-ROM tower, can directly access an unlimited number of CD-ROMs at the same time, do not have to wait to change the disk, fast, easy to use, does not take up space and no hardware maintenance problems.
Performance after installing a virtual drive
After installing a virtual drive system, users can see one or even more CD-ROM drives on the Windows 95/98/NT platform, and each virtual drive is like a real CD-ROM drive, whether it's in MS-DOS mode, Explorer, or even in the Control Panel, you'll see the disk drive, which is the same virtual drive as the real one. are the same virtual CD-ROM drives as the real ones.
2. I. The origin of the name Bluetooth
The name Bluetooth comes from the 10th century Danish king Harald Blatand - English translation is Harold Bluetooth. in the preparatory stage of the industry association, the need for a very expressive name for this new technology. Industry organizers, after a night of discussion about the history of Europe and the future of unlimited technology development, some felt that King Blatand's name would be a perfect fit. King Blatand united what is now Norway, Sweden, and Denmark; just like the technology that will soon be available, the technology will be defined in a way that allows for coordinated work between different areas of industry, such as computing, cell phones, and the automotive industry. automotive industries to work together. The name was thus settled.
In the Danish city of Jelling, there is a monument in the church that commemorates the achievements of King Blatand and his father, Denmark's first king, Gorm the Old. Interestingly, this particular stone was lost after a battle between Harald and his son Sven Forkbeard, and no one has seen it for almost 600 years; Sven won (and exiled his father), and because the stone with the ancient Norse inscription was an honor to Harald, Sven buried it. It wasn't until the last few years that a farmer became curious about this large mound of dirt on his farm and finally discovered the stone.
The logo was originally designed by Scandinavian when the business association was announced. The logo retains the traditional character of its name, containing the Old Norse letter "H", which looks very similar to an asterisk and a "B", both of which can be seen when looking closely at the logo.
Second, the introduction of Bluetooth technology
"Bluetooth" (Bluetooth) was originally the name of the king of the tenth century united Denmark, and now take its meaning of "unity", used to name the wireless local area network communication standards intended to unify the Bluetooth technology. Bluetooth technology. Bluetooth technology is a wireless network technology jointly launched by Ericsson, IBM and five other companies in 1998. Subsequently established Bluetooth technology special interest organization (SIG) to be responsible for the development of the technology and the development of technical agreements, now more than 1,800 companies around the world to join the organization, the recent Microsoft Corporation also formally joined and become one of the leading members of the SIG organization.
Bluetooth is an open standard for wireless data and voice transmission, which connects various communication devices, computers and their terminals, digital data systems, and even home appliances wirelessly. Its transmission distance is 10cm ~ 10m, if you increase the power or add some peripherals can reach 100m transmission distance. It adopts 2.4GHz ISM band and FM, frequency hopping technology, using right-to-error correction coding, ARQ, TDD and baseband protocols.TDMA is 0.625μs per time slot, and the baseband complies with the rate of 1Mb/s. Bluetooth supports real-time voice and data transmission at 64kb/s, with voice coding as CVSD, and the transmit power is 1mW, 2.5mW, and 100mW, respectively, and uses a globally standardized 48-bit device identification code. Because Bluetooth uses a wireless interface to replace wired cable connections, it is highly portable and applicable to a wide range of occasions, plus the technology is easy to promote because of its low power consumption, low harm to the human body, and simple, easy-to-implement applications.
Bluetooth technology
SIG organization in July 26, 1999 launched the Bluetooth technology specification 1.0 version. The system structure of Bluetooth technology is divided into three main parts: the underlying hardware module, the intermediate protocol layer and the high-level application. The underlying hardware part includes radio frequency hopping (RF), baseband (BB) and link management (LM). The wireless frequency hopping (RF) layer filters and transmits data bit streams through microwaves in the 2.4GHz unauthorized ISM band. This protocol layer mainly defines the conditions that Bluetooth transceivers need to satisfy for normal operation in this band. Baseband is responsible for frequency hopping and the transmission of Bluetooth data and information frames. Link management is responsible for connecting, establishing and dismantling links and performing security controls.
Bluetooth technology combines circuit-switched and packet-switched features to enable asynchronous data communications, support for up to three simultaneous synchronous voice channels, and the ability to use a single channel to transmit both asynchronous data and synchronous voice. Each voice channel supports a synchronous voice link of 64 kb/sec. Asynchronous channels can support asymmetric links with a maximum rate of 721kb/sec at one end and 57.6kb/sec at the other, as well as symmetric links with a rate of 43.2kb/sec.
The intermediate protocol layer includes a logical link control and adaptation protocol, a service discovery protocol, a serial port emulation protocol, and a telephony communication protocol. The logical link control and adaptation protocol has the function of completing data disassembly, controlling quality of service and multiplexing protocols, and this layer is the basis for the implementation of the other layers. The Service Discovery Protocol layer provides a mechanism for upper layer applications to discover the services available in the network and their characteristics. The serial port emulation protocol layer has the capability to emulate a 9-pin RS232 serial port. The telephony communication protocol layer provides call control instructions for voice and data between Bluetooth devices.
The Host Control Interface (HCI) layer is the interface between hardware and software in the Bluetooth protocol, and it provides a unified command interface for calling hardware such as baseband, link management, status and control registers. When Bluetooth devices communicate with each other, the protocol software entities above the HCI run on the host computer, while the functions below the HCI are performed by the Bluetooth device, and the two interact with each other through a transport layer that is transparent to both ends.
At the top of the Bluetooth stack are various high-level application frameworks. Typical ones include dial-up networking, headset, LAN access, file transfer, etc., which correspond to one application mode each. Various applications can realize wireless communication through their corresponding application modes. Dial-up network applications can access the Piconet through the emulated serial port, and data devices can also access the traditional LAN; users can realize wireless transmission of audio streams in cell phones and earbuds through the Audio layer in the protocol stack; multiple PCs or laptops can quickly and flexibly transfer files and **** enjoy information without any wires, and multiple devices can also realize synchronous operation. This also allows for synchronized operation of multiple devices.
In short, the entire Bluetooth protocol is simple, using the retransmission mechanism to ensure link reliability, in the baseband, link management and application layer can also be implemented in a graded variety of security mechanisms, and through the frequency-hopping technology can be eliminated in the network environment from the interference of other wireless devices.
Application Prospects
Bluetooth technology has a wide range of applications, and can be widely used in local area networks for various types of data and voice equipment, such as PCs, dial-up networks, laptops, printers, fax machines, digital cameras, cell phones and high-quality headsets, etc. Bluetooth wireless communication will be the above equipment into a micro-micro-network (Piconet), and multiple micro-micro-networks can also be connected to each other. Multiple micro-micro-network can also be connected to each other, thus realizing the communication between various types of equipment at any time and anywhere. Typical environments where Bluetooth technology is applied include wireless office environment, automobile industry, information appliances, medical equipment, as well as school education and factory automatic control. At present, the initial products of bluetooth has come out, some chip manufacturers have begun to improve the chip with bluetooth function. At the same time, some powerful software companies or the introduction of their own protocol stack software, or with chip makers to launch a Bluetooth technology to achieve the specific program. Nevertheless, Bluetooth technology to really popularize the following problems need to be solved: first of all, to reduce costs; secondly, to achieve convenient, practical, and really bring benefits to people; thirdly, to be safe, stable and reliable work; fourthly, to introduce an authoritative international standard as soon as possible. Once the above problems are solved, Bluetooth will rapidly change the way people live and work, and greatly improve people's quality of life
3. The abbreviation of Basic Input/Output System, the full name is ROM-BIOS, which means Read-Only Memory Basic Input System. In fact, it is a set of programs that are solidified into the computer to provide the lowest level of direct hardware control. Since it is a "program", of course, belongs to the "software". But BIOS is not the general software, figuratively speaking, BIOS is connected to the software program and hardware devices between a "bridge". A "converter", responsible for solving the immediate requirements of the hardware, and according to the software requirements for the operation of the hardware specific implementation.
COMS stands for Complementary Metal Oxide Semiconductor. It means Complementary Metal Oxide Semiconductor Memory. CMOS is memory, a battery-powered memory (RAM) used in most computers today. As "memory", there is no doubt that it is "hardware". So what is the relationship between CMOS, the "hardware" and BIOS, the "software"?
First, we should clarify the following three concepts:
1. In general, what we call BIOS setup actually refers to the process of modifying the parameters of the hardware system through the setup program.
2, ROM, abbreviation of Read-Only Memory. Meaning read-only memory, which is characterized by only read, can not be modified, and power outages can still keep the data is not lost. The startup mode is POST (Power On Self Test).
3, RAM, Random Access Memory abbreviation. Random Access Memory (RAM), characterized by read-write, modifiable, and CMOS RAM powered by an internal battery, so the data can be stored for a long time.
It is for this reason that we:
One, the use of ROM features, use it to put the setup program required to modify the system parameters, because this program is fixed and indispensable.
Two, using the characteristics of RAM, used to store the system parameters changed by running the setup program, so that it can be read and written at any time, that is, change and use. Therefore, BIOS setup is also called CMOS parameter setting. So, what kind of role does BIOS play in the overall computer system?
Functionally, BIOS has the following three roles:
1, self-test and initialization procedures;
2, hardware interrupt processing;
3, program service requests.
Currently, there are two main types of BIOS on the market, AMI BIOS and Award BIOS. The former is mostly found in 286 and 386 systems, which are easy to operate and work reliably, but are lagging behind in the popularization of green energy-saving systems; while the latter is the first choice for models above 586, and is now most used in the 4.x version. Due to product differences, the BIOS setup program is not the same way to enter: AMI BIOS setup program, it is best to use its own default settings, setup method is: AMI BIOS, in the operating interface, select "AUTO CONFIGRATION WITH BIOS DEFAULTS (with BIOS default values automatically)"; for the AMI BIOS, select "AUTO CONFIGRATION WITH BIOS DEFAULTS"; for the AIOS, select "AUTO DEFAULTS". For AMI BIOS, select "AUTO CONFIGURATION WITH BIOS DEFAULTS" in the interface; for Award BIOS, select "LOAD SETUP DEFAULTS".