QNX

Greetings, All! What kind of OS is this - QNX? [REAL ZX]

Press RESET immediately, Nikolaj Amosov! On Fri, 04 Jul 03 21:00:10 +0400, Nikolaj Amosov wrote: NA>>> What kind of OS is this - QNX? KF>> www.ya.ru -> QNX. NA> Well, I don’t have access to the Internet and never will. I also remembered the URL: www.swd.ru QNX Philosophy This chapter contains the following sections: + What is QNX? + QNX microkernel architecture + Interprocess communication + QNX network What is QNX? The main function of the operating system is resource management computer. All actions in the system - execution planning application programs, writing files to disk, sending data via network, etc. - must function together so seamlessly and transparently oh, how possible. Some environments require more stringent resource management and execution planning than others. Real-time applications for example, depend on the operating system's processing of many events within specified time limits. What m The faster the operating system responds, the larger the application real time has the ability to maneuver in critical situations. The QNX operating system is ideal for real-world applicationstime. It provides multitasking, priority preemptive scheduling and fast context switching are all necessary components of a real-time system. QNX is also remarkably flexible. Developers can easily customize operating system to meet the needs your applications. QNX allows you to configure the system so that use only the resources necessary for work, from "skel this" kernel configuration with several small modules up to deployed network system adapted to serve hundreds of users. QNX owes its unique degree of efficiency, modularity and simplicity to two fundamental principles: microkernel architecture; interprocess communication using messages. QNX microkernel architecture QNX consists of a small kernel responsible for a group interacting processes. As shown in the following illustrations, its structure resembles a "team" rather than a hierarchy, since several players of equal rank interact with each other and with "protector" - the core. fig: ./images/modules.gif The QNX microkernel that coordinates system managers. Microkernel The kernel is the basis of any operating system. On some systems the "kernel"includes so many features that it is a complete operating system! But the QNX microkernel is really a kernel. Firstly, as a core real-time operating system, the QNX microkernel is very small. Secondly, it provides only two necessary functions: Messaging (message passing) - the microkernel processes the flow of all messages all processes in the entire system Planning (scheduling) - the scheduler is part of the microkernel and is called whenever the state of a process changes as a result of messages or interruptions Unlike processes, execution of the microkernel itself is never planned. Entry into the microkernel is only a direct result of calls to it either a process or a hardware interrupt. System processes All QNX services other than those provided by the microkernel are provided by standard QNX processes. A typical QNX configuration has the following system processes: Process Manager (Proc) File System Manager (Fsys) Device Manager (Dev) Network Manager (Net) System processes and user processes System processes are virtually no different from any user process programs - they do not have any inaccessible to user processes private or hidden interfaces.It is this architecture that gives QNX unprecedented extensibility. Since most operating system services are provided by standard QNX processes, increasing the operating system is very simple: you just add new programs that provide new services! In fact, the boundary between the operating system and the application may be very blurry. The only real difference between the system services and applications - that these services allocate resources for clients. Let's assume you wrote a database server. How is this process should be classified? Just like the file system allows requests (in QNX - messages) to open files and reads/writes data, the database server also works data. They are very similar (despite the fact that requests to the database server data may be more complex) provided by the sets primitives (message-based), which in turn provide access to the resource. These are independent processes that can be written by the end user and run as needed. The database server could be considered a system process under some circumstances settings and application - for others. It really doesn't matter meanings! The important thing is that QNX allows you to implement such processes without modifications of standard elements of the operating system. Device DriversDevice drivers are processes that rid the operating system from having to deal with all the details required for support for certain hardware. Since drivers run as standard processes, adding the new driver for QNX does not affect any other part of the operating system systems. The only change the QNX environment needs is to start new driver. Once initialization is complete, drivers can: disappear as standard processes, becoming extensions of the system the process with which they are associated; maintain individuality as standard processes. Interprocess communication When multiple processes are running simultaneously, as in typical multitasking environments in real time, operating system must provide mechanisms for processes to communicate with each other. Inter-process communication (IPC) is key to application design as a set of interacting processes, where each process performs its clearly defined task. QNX provides a simple but powerful set of interprocess interactions that greatly simplify the work of creating applications, consisting of interacting processes. QNX as a message-passing operating system QNX was the first commercial operating system of its kind,which used message passing as a fundamental means interprocess communication. QNX owes much of its power to simplicity and elegance of complete integration of the transfer method messages throughout the system. A message in QNX is a packet of bytes sent from one process to to another. QNX does not attach any importance to the message content - the data in the message is meaningful only to the sender of the message and for its recipient. Message passing allows processes to do more than just pass data each other, but also provides a means of synchronizing execution several processes. When processes send, receive, and respond to messages, they are subject to various "state changes" that influence when, and for how long, they can be performed. Knowing them states and priorities, the microkernel can schedule all processes as efficiently as possible using the available CPU resources a. Real-time applications and other critical applications in general require a reliable form of communication between processes, because processes that make up such applications are strictly interrelated. QNX's message passing provides orderliness and reliability. QNX networkIn its simplest form, a local area network provides a mechanism for sharing files and peripherals among multiple connected computers. QNX goes far beyond this simple concepts and integrates the network into a single homogeneous set of resources. Any process on any machine on the network can directly use any resource on any other machine. From the point of view applications there is no difference between local or remote resource - access to them is provided by ordinary means. If only this was not the case, the program would need special code to be capable of reporting whether a file or device type resource is located on local computer or on some other network node! Users can access files anywhere on the network, use any peripheral devices and run applications on any machine on the network (if they have the appropriate permissions). Processes by entire network can communicate in the same way as the processes running on the same machine. Ubiquitous messaging QNX enables mobile networking. Single computer model QNX is designed as a network operating system. QNX network is similar rather on a mainframe than on a set of microcomputers. Users simply aware of the wide range of resources available for useany application. But, unlike the mainframe, QNX provides both highly sensitive environment, since the corresponding computing power to meet user needs can be available on any site. In process control environments such as PLC and other real-time I/O devices may require more resources than other, less critical applications like word processor. The QNX network is responsive enough to to support both kinds of applications at the same time - QNX allows you to concentrate computing power where and when it is needed necessary. Flexible networking QNX networks can be interconnected using a variety of hardware and industry standard protocols. New network architecture can be presented at any time without interfering with the operating system, since it is completely transparent to application programs and users. Note: List of networking hardware supported by QNX, via some time may increase. For details, see your network hardware documentation. the funds you are going to use. Each node on a QNX network is assigned a unique number, which becomes its identifier. This number is the only meansallowing you to determine whether QNX is running as a network or as an operating system single computer system. This degree of transparency is another example of outstanding power QNX message passing architectures. Important functions in many systems like networking, interprocess communication, or even message passing is formed at the top of the operating system, not integrated directly into the core. The result is often awkward, ineffective interface with "double standards". QNX is based on the principle that efficient communication is the key to efficient work. Thus, message passing is the cornerstone the stone of the QNX architecture, increasing the efficiency of all transactions for all processes in the entire system, do they communicate through the system computer bus or through a kilometer of coaxial cable. Let's take a closer look at the structure and functions of QNX. NA> Hammer... Scored.

Press RESET immediately, Roman Alexandrov! On Fri, 04 Jul 03 23:33:36 +0400, Roman Alexandrov wrote: NA>> Well, I don’t have access to the Internet and never will. RA> No modem? Be-e-e-day... And some suffer like this without a modem, through “butt-cutting”. They say beeline, $10/month and gigabytes of traffic for free. I don't believe it. I know that every megabyte costs something. And in this month You can drag out megabytes or, on the contrary, download an enormous amount. Something is wrong here... :-/ By the way, the question is on topic. I understand that there are only 4 options connections: via serial interface, via the same interface but with IRDA emulation on it, via IRDA and via bluetuth. And on top This is all the phone pretends to be a modem and after submitting some AT commands start PPP between the computer and the phone (namely telephone, and not the Internet provider), and the telephone has its own address and IP over GPRS works. Am I right? If I’m right, then where does the myth come from that you desperately need a special software like a phone driver (where all sorts of melodies are uploaded) for Windows? You can also install generic 115200 modem, just a list Where can I find AT commands... :-/

Hello Kirill! Monday 07 July 2003 23:56:16 Kirill Frolov -> Nikolaj Amosov: KF> On Sun, 06 Jul 03 20:49:23 +0400, Nikolaj Amosov wrote: NA>>>> I’m connecting with MAC on 14400 disgustingly - NA>>>> I even had to slow down NA>>>> ports up to 9600. Now at least it doesn’t hang... KF>>> And I’m connecting with Vega at 1200... NA>> Is it like XTRom or something? KF> Hayes! I thought that on haes the lower speed is 2400. How is it necessary? perverted to connect to 1200? ;) [REAL ZX]

Press RESET immediately, Nikolaj Amosov! On Tue, 08 Jul 03 21:06:09 +0400, Nikolaj Amosov wrote: NA>>>>> I’m connecting with MAC at 14400 disgustingly - NA>>>>> even had to slow down NA>>>>> ports up to 9600. Now at least it doesn’t hang... KF>>>> And I’m connecting with Vega at 1200... NA>>> Is it like XTRom or something? KF>> Hayes! NA> I thought that the lower speed on the haes was 2400. You didn't think well. Khaes (branded) had speeds of 5 bits/sec. Amplitude modulation... (Bell103/113, V.21) From standard protocols lowest speed hayes-smartmodem modem -- 300bit/sec, modulation frequency, the Bell212A protocol can still be supported by some (mostly old) modems. There is also a standard asymmetrical one V.23 protocol -- 1200bit/s in one direction and 75bit/s in the other, frequency modulation. Every modem can whistle at 1200bit/sec, often in 3 different standards: American Bell212A, standard V.22 (modulation method in both cases OFM-4) and the already mentioned V.23 (FM). Well, V.22bis is already the first standard protocol for all 2400 bps, quadratic modulation. By the way, I want to remind all nodes that if their station does not respond in ZMH using the V.22 protocol (this is in Z2, in Z1 there will be Bell212A) - they violate fidonet policy. NA> How perverted is it necessary to connect to 1200? ;) AT*N0 or ATN0, or AT&N0 - depends on the modem.

Hello, Kirill! 11 Jul 03, 01:08, Kirill Frolov wrote to Nikolaj Amosov on the topic "Re: QNX": NA>> And how long will this connection be and is the price included? NA>> access to the Internet? KF> It seems like beeline is the cheapest and you pay less than $10 a month there KF> is not allowed. Well, if you don’t talk, don’t send SMS and don’t go on the Internet, then the most cheap is the federal MTS, something around 2.6 dollars per month. Happy connections. Roman.