DD159519A3 - OPERATING AND SERVICE PROCESSOR, PREFERABLY FOR COMPUTER PLANTS - Google Patents

Abstract

Operating and service processor, preferably for computer systems. By the invention, a high availability, increased ease of use and improved display options are to be achieved. For each interface to be operated (standard interface and special interface) a microcomputer and an adapter arrangement is available. To a further microcomputer arrangement, a keyboard, an acoustic signaling device and maintenance and control means are connected. Two screen monitors are connected to control means with the interposition of an exchange circuit. A printing unit is connected via a printer adapter to two of said microcomputer arrangements. The microcomputer assemblies, a portion of the adapter assemblies, and the screen monitor control means are coupled to a common universal bus. Fig. 1

Description

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Title of the invention

Operating and service processor, preferably for computer systems

Field of application of the invention

The invention relates to an operating and service processor, which is preferably provided for the operation and support of the maintenance and diagnostics of computer equipment, but also for Bediemmgs- and service support tasks in other complex information processing systems, such. B .. in systems of telephone switching or in process control systems based on digital Eechner can be used.

Characteristic of the known technical! Solutions It has been state of the art for some time that complex digital systems, e.g. EDP systems, instead of being operated by conventional maintenance and control panels with buttons, switches and indicator lights via operating units or operating and service processors. Such devices replace the usual control and display means by a combination of keyboards and viewing devices based on cathode ray tubes. Programmed devices are provided for controlling these means. The keyboards and display devices replace not only the means already mentioned, which are preferably used for communication between the service technician and the hardware of the system, but also alphanumeric input / output devices such as teletypewriters, electric typewriters and the like, previously used to communicate the actual Operators were provided with the operating system of the arrangement.

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In this case, an operating device üblieherweise an arrangement of a keyboard and a viewing device, 'as optional additives often a printer and a Selektierstift are connected. To control a correspondingly designed microprogrammed control unit or one of the many commercially available minicomputers is provided.

Such a control unit is described, for example, in computing data processing, at 2/79 _s S, 32 und.34.

In modern systems, a key task is not only manual operation, but support for automated system diagnostics, initialization control, and remote diagnostics support from a remote service point. such as B. Floppy disc drives, hard drives or the like stet stet. Examples are included in the periodical information material Auerbach Computer Eeport. Such operator and service processors become critical points in the sense of reliability of the overall system by performing many functionally important tasks. An obvious way out exists in a multiple arrangement. This is relatively easy if the interfaces to be controlled allow a multiple connection to the system to be operated.

For channel interfaces of EDY systems and similar computer arrangements this is generally unproblematic. For the special interface for performing interventions in the hardware of the system to be operated, a suitable design has already been specified in WB 127 351. The switching must be done by manual intervention. In 1978, the IBM Data Processing Division, "A Guide to the IBM 3033 Processor Complex and Multiprocessor Complex," describes an arrangement consisting of two operator stations, each of which has a controlling processor, a keyboard, a display device, and a floppy disk Drive has.

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Furthermore, each of the processors has its own connector for one of the standard interface positions of the I / O channels of the machine to be operated »Several special interfaces are provided for which both processors can access. ,

Also, between the processors exchange registers are arranged, Thus, a dynamic configuration control is possible so that either each function or only a part of the functions can be performed by each of the two operator stations * In particular, it is possible that in case of failure or shutdown of the operator stations others assumes all functions.

Another known embodiment provides that the service »processor with its external memories and interfaces is physically integrated into the central unit of the system to be operated. For manual operation and information output, several VDUs and printing units can be connected. In such an embodiment, a certain security against failures is given by the multiple arrangement of said input / output devices, · A failure of the service processor itself, however, leads to the failure of all functions transmitted to him. The applications of such an arrangement are limited insofar as a physical integration in the central unit only makes sense if it is mechanically small and compact enough to accommodate the additional facilities without difficulty.

For larger systems, disassembling the operator and service processor is a practical necessity. A disadvantage of the known devices, the relatively high cost, which results in particular when starting from trust wedge double arrangements are provided. Furthermore, it is disadvantageous in many devices that the Darstell capacity for an operator station is relatively low, so that information that is to be displayed constantly a _ä can be made visible only by a change of the displayed image.

Finally, with many devices, "degradation" of response times occurs when multiple punctures are performed simultaneously. This partly forces restrictions on the operating options. For example, certain images may not be requested on a known device if certain diagnostic programs are being processed in the system.

Object of the invention

The aim of the invention is to provide an operating and service processor, which ensures a high availability and a significantly increased ease of use, among other things by improved display options, with relatively little effort.

Essence of the invention

The object of the invention is to specify the structure of an operator and service processor which provides, at relatively little expense, advanced display capabilities in which the performance reduction in situations with multiple concurrent requests is low and which has high availability. Since it is self-evident that a high level of availability can be ensured by installing several complete devices (this is always essential in extreme conditions), but this measure represents a considerable increase in effort, an increase in the availability of the individual device should be ensured by measures be provided, which make it possible to restore the operational readiness very quickly in the event of a fault.

According to the invention the object is achieved in that for interface to be operated at least a first and second microcomputer arrangement and an adapter arrangement is provided that a keyboard, an acoustic signaling device, and maintenance and control means are connected to a third microcomputer array, two screen monitors are arranged downstream of corresponding control means with the interposition of an exchange circuit, that a printing unit with intermediate

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circuit of a printer adapter of both the third microcomputer arrangement and the first microcomputer arrangement is arranged downstream, that all microcomputer arrangements, the control means of the screen monitors and at least a part of the adapter arrangements of the interfaces to be operated are connected to a common universal bus , wherein the central control means of this universal bus are arranged in the context of the third microcomputer arrangement, that the first and second microcomputer arrangement are implemented in a similar manner and that the two screen monitors are arranged together with the keyboard in the complex. ,

Here, the printer adapter is designed such that the signals for the printing unit are connected to selection circuits which are connected to the third and first microcomputer arrangement, said. Selection circuits is preceded by a selection line which is connected to the third microcomputer arrangement and that this selection line is fed back on the input side to the first microcomputer arrangement and the central control means of the universal bus are designed so that the lines for the master selection of the universal bus zunäch to the master request circuitry of the third microcomputer array and subsequently to conjunctive connections to a dip-flop connected to the third microcomputer array.

embodiment

In the following embodiment show:

1 shows the block diagram of the operating and service processor according to the invention,

Pig. 2: the division of the screen presentation, Pig. 3ϊ the outer circuit,. ,

Pig. 4: the design of the maintenance field, Pig. 5: Parts of the design of the control panel, Pig. 6: the layout of the keyboard,. , Pig. 7: Printer Adapter Details ·, Pig. 8: Details of the central control means of the universal bus.

The block diagram of the operating and service processor according to the invention is shown in FIG. The arrangement is realized as a modular multi-microcomputer system, wherein a plurality of microcomputer arrangements 2; 3; 4 »control means 5 for two screen monitors 6; 7 and a standard interface adapter 8 are interconnected. In this case, the central control means 9 of the universal bus 1 are arranged within the scope of the first microcomputer arrangement 2. Furthermore, the microcomputer arrangement 2 are arranged downstream;

an acoustic signaling device 10 with a downstream loudspeaker,

a keyboard 11,

a daytime clock 12,

- Maintenance and service 13 »

- The first connection of a printer adapter 14, which is a printing unit 15 downstream.

The second microcomputer assembly 3, the second terminal of the printer adapter 14 is connected downstream.

The third microcomputer assembly 4 are two floppy disk adapter 16 Ploppy disc drives 17; 18 and via a special interface adapter 19, the special interface 20 downstream. , ,

The standard interface 21 is connected directly to the standard interface adapter 8.

In the connections between the control means 5 for the screen monitors 6; 7 and these monitors, an exchange circuit 22 is arranged.

The arrangement is based on the principle that two interfaces are to be operated, namely the standard interface (SIi ¹ ) 21 for connection to one of the standardized input / output channels of the system to be operated and the special interface (SPIP) 20 for the direct connection to the hardware of the system to be operated.

In this case, the communication between the operating personnel and the operating system of the system to be operated is preferably carried out via the standard interface 21.

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The special interface 20 is intended for direct intervention in the hardware of the system to be operated, for example ₀ for displaying signals, changing memory and register contents, for operating the logic in single-clock mode and the like for each of these Thus, a separate microcomputer is available for each of the two essential task complexes of the operating and service processor, so that, in principle, no degradation of the power occurs if requirements of both interfaces have to be processed at the same time «.

In order to ensure the functional scope of the overall device, the communication of the two microcomputer arrays 3; 4 untei each other and with the other functional complexes required * It is advantageous if this communication is subject to as few restrictions as possible. This will allow shared resources to be used more effectively, and it is possible to. Control tasks that require only a small fraction of the total uptime (i.e., that are rarely requested or that do not require time critical debiting) add $ 3 to the microcomputers. transfer and thus save the effort for further tax funds. Thus, the microcomputer 3, the control of the printing unit 15 and the microcomputer 4, the control of the floppy disk drives 17; 18 assigned. ·

The microcomputers 3 »4 are completely identical to each other. The following requirements are placed on their design: ~ internal memory capacity of at least 32 kbytes (RAM).

- Connection to time-multiplexed bus with ^H multi-master "properties such that each of the microcomputer 3" 4 can work as master and slave and that unrestricted access to the internal RAIi Sp ei rather universal bus 1 from are possible, without affecting internal processes (with the exception of a possible slight delay),

Sufficient number of I / O circuits for controlling peripheral devices,

-. Having a powerful interruption system to handle multiple interrupts from Universal Bus 1 and I / O circuits.

There are already commercially available microcomputer assemblies that can meet these requirements. Therefore, a more detailed description of the internal structure of these microcomputer "arrangements is not required. Also, bus systems with which the universal bus 1 can be realized, already known«.

The following requirements are imposed on the universal bus 1: ⁿ Multi-master ⁿ characteristics, ie each of the connected devices must in principle be able to work as hysteresis or slave, parallel transmission of data and addresses, sufficient address space to access all storage means access the connected facilities.

In the work of Rolander, "Intel Multibus Interface", application note AP 28, IiTTEL 1977, an internationally used bus system is shown, to which there are also a large number of modules and puncture modules. Y / eiterhin is (G06I ^1/227 967/4 WP) a bus system has been proposed, which can be in the arrangement described herein advantageously used in the VVP application "bus system for connecting logical puncture modules ™.

The further microcomputer arrangement 2 is preferably used to control the "manual interfaces" (acoustic signaling 10, keyboard 11, maintenance and control means 13, time of day clock 12). These devices are connected to the input-output circuits of the microcomputer array 2.

Furthermore, in the context of the microcomputer arrangement 2, the central control means 9 of the universal bus 1 are arranged. These control means are used to generate selection signals, to detect errors and the like. These central control means 9 also connect to input / output circuits of the microcomputer arrangement 2.

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The essential task of the microcomputer arrangement 2 consists in the cyclical query of the manually zubetbetigenden keys and switches, in the query and 'display of the time of day clock 12 and in the control of lamp or LSD displays ·' 'The time of day clock 12 is a battery-powered counter in CMOS technology that counts seconds, minutes, hours and days at a resolution of 1 second. The entire counting range is designed for approximately 143 years.

Counting continues even when the power is off. When the device is turned on the microcomputer assembly 2 causes a cyclic display on the screen monitor 7 <The setting and evaluation is performed by programs that preferably run in the microcomputer array 2. In normal operation, the purpose of the microcomputer array 2 is essentially to relay requests from the manually operated devices, particularly from the keyboard 11, to the other microcomputer arrays 3-j'4 In accordance with the invention, the microcomputer assembly 2 is also capable of evaluating the keys and sutures differently from normal operation so as to be used for medical and diagnostic interventions in the apparatus itself. in which the micro-bucket arrangement 2 uses the universal bus 1 alone (while the processing in the other facilities is at rest).

By appropriate programs, it is possible to display memory contents from the keyboard 1, to change, to trigger diagnostic Tesi, etc. For information output while both the printing unit 15 and. Also the screen monitors 6; 7 used. In order to facilitate the use of the printing unit 15, the printer adapter 14 is designed as a dual adapter, so that the printing unit 15 is provided both by the microcomputer assembly 2 for diagnostic purposes and by the microcomputer assembly 3 for normal output operations The access on the part of the microcomputer arrangement 2 has the higher priority. The particular advantage of this refinement is that it can then output extensive error messages to whom

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the universal bus 1 is not functional. By programs that are resident in the microcomputer assembly 2, a comprehensive error analysis can be realized, the results of which can thus always be output in more detail form, namely on the printing unit 15 and the display on one of the screen monitors 7. Since itself In the event of serious defects in the sails, one of the two output options is able to function, very detailed error information can be transmitted to the service personnel. This contributes significantly to the shortening of the troubleshooting times and thus to the rapid restoration of operability. The microcomputer assembly 2 per se requires an equipment with at least 8 kbytes EOM, 1 kbyte EM and a sufficient number of input / output circuits.

In this case, an implementation of commercially available assemblies is possible.

In connection with the connected bus system, details of such a microcomputer arrangement are also described in the WP application "Bus system for connecting logical puncture modules (Υ / Ρ G06F / 227 967/4).

The control means 5 for the screen monitors 6; 7 have the task of Yideo and sync signals for the independent display of two images of 24 Zeilena 80 characters to deliver. In addition to the actual control circuits, they contain sufficient BAM X capacity for image storage. The KAM arrangements must be accessible via the universal bus 1. These requirements can be easily met with commercially available modules. Advantageous because of the cost reduction by multiple use of many control circuits for both screen monitors 6 j 7, the high storage capacity and the provision for speeding up frequently used operations appears to use an arrangement as described in the WP application "arrangement for displaying information on television ^viewing devices ¹¹ (YiP H05K / 227 289/3) The exchange circuit 22 connected upstream of the screen monitors 6, 7 serves to exchange the images between the two screen monitors by means of a manually operated switch.

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This offers on the one hand advantages in the testing and adjustment of the monitors and on the other hand also allows the continuation of work in the event of failure of one of the two screen monitors 6; 7 · None is possible. Information lost, nur.ist the ease of use is reduced by the occasionally necessary switching.

The standard interface adapter 20 must be set up for the independent control of three device functions (1st screen, 2nd screen, printer). A suitable solution is shown in the HSP instruction "Adapter arrangement for connection to a standard interface" (HiIP G06F / 226 184). The special interface adapter 19 serves to establish the connection between the special interface 20 and the input / output circuits of the microcomputer assembly 4. Since the special interface 20 depends essentially on the design of the system to be operated, a detailed description of this complex can be omitted. Essentially, tasks of adaptation, level conversion, and serial / parallel as well as parallel / serial conversion are to be performed, which can be easily accomplished with commercially available circuit diagrams.

As an example of the design of a special interface, reference is made to WP 127 351.

The reason that for the standard interface 21 of the adapter ί as an autonomous device connected to the universal bus 1 lsi while the special interface 20 is controlled directly via the adapter 19 of the microcomputer assembly 4, is in the high speed requirements the standard interface that a microcomputer controller can not meet.

The floppy disc adapter 16 and the floppy disc drives 17; Realize the external memory for the majority of the programs of the operator and service processor itself as well as for microprograms, diagnostic information, etc. of the:

System.

It is possible to realize it with commercially available modules «, '

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Fig. 2 shows the division of the representation on the two screen monitors 6; 7 ·

The display capacity is 24 lines each to 80 characters. On both monitors together 3840 characters can be displayed.

Each representation on one of the screen monitors 6; 7 is built from a contiguous memory area of 1920 positions. A memory area that can be represented in this way is referred to below as "picture"

The entire display capacity of the screen monitor 6 is used to represent one of various images for operation, maintenance and display purposes. In particular, a so-called program image is provided which is used for I / O operations under one of the device address positions of the standard interface adapter 8. The change between the individual displayable images is done by keyboard inputs.

By contrast, the display capacity of the screen monitor 7 is divided into two areas of 12 lines each. In the upper area also different pictures can be displayed. In particular, here is a second program image can be displayed, which is accessible at a second device address position of the standard interface adapter.

This makes it possible, among other things, to divide the operating system messages of the system to be operated into two independent, simultaneously displayable areas and thus to achieve a very clear presentation. The lower 12 lines contain fixed formatted representations.

These includei

1st ZE states. Important states of the system to be operated are constantly displayed in 5 lines (working state, waiting states, current PS? /, IPL device address, etc.). In particular, special states are shown in more detail than hitherto customary. Thus, when the comparison stop is activated, all essential information, such as mode, stop address, etc., is always visible.

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2. Device states. In 4 lines, there are 4 fields of 20 character positions each, which contain indications of internal device functions. These are the devices

•. Screen 1 (corresponds to the program screen for Monitor 6). Screen 2 (corresponds to the program screen for Monitor 7). Printer (printing unit 15). , , Floppy disk drives 17; 18 · '. ,

The formatting of the individual display areas is always the same in principle?

1 ··. Line headline (static, identifies the respective device function)

2nd line: configuration state (selected operating mode and the device address in case the accessibility via the standard interface adapter 8 is possible)

3. Zeiles Arbeitssustand at each interface (such as _e in Euhe

Command execution, application o. Ä.)

4th line Internal working state (eg, whether an input from

_: the keyboard is possible, whether · device errors exist, etc.)

3. Warning area. 2 lines of 36 characters each are provided for the display of internal error messages and warnings.

4. Time of day clock area In 2 lines of 44 characters the time and the current date are displayed (the date with explicit indication of the current ¥ / o clientages).

5 · 3? Astatur ~ status line. The last line displays keyboard states and explains the function of selected buttons. ^{; i:.}

Fig. 3 shows the structure of the exchange circuit 22. It can be seen that the native video signals from the control means 5 by pressing a switch (CRT OEOSSOVER) to each other of the screen monitors 6; 7 can be sent.

The sync signals for. Both monitors are identical, so there is no need for switching. The illustrated in Fig. 3

be arranged when the monitors 6; 7 additional display signals require, for example, if additional signals for intensity control are required.

This can be in case of failure of one of the screen monitors 6; ? the picture in question can be made visible on the other monitor, so that in many cases a further work (albeit with reduced ease of use) is possible. The fact that the exchange circuit 22 acts directly on the video signals (and does not become effective in the context of the switching means 5) has the advantage that the image exchange for the software is completely transparent. The disadvantage that failures in monitor-specific cables of the switching means 5 can not be ignored in practice is not too serious, since experience has shown that the reliability of monitor assemblies is considerably lower than that of logic circuits. -

The pig. 4; 5 show the design of the maintenance field and of parts of the control panel. In both devices, the keys, switches and displays are essentially connected to the microcomputer assembly 2 as maintenance and control means 13. The differences between the two fields are in the nature of their arrangement. The maintenance area is concealed. By contrast, the control panel is within the immediate reach of the operator.

The elements of the maintenance field have the following function?

1. OPERATION MODE. The switch is evaluated by the software during initialization and determines which operating state is initialized. Furthermore, it serves to switch on or leave the internal maintenance state (MINT MODE) during operation.

2. CRT CROSSOVER. This is the operating element for the replacement circuit 22.

3. IMPL. Pressing this key triggers a reset in the entire arrangement. Upon release, an "initial microprogram load" from one of the floppy disk drives 17; 18 instead. After that, the arrangement takes its on.

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4 «DIAG INIT. Pressing this key triggers a reset in the entire arrangement. After releasing, an "initial microprogram load" of one of the

  Floppy disk drives 17; 18 instead, but · for diagnostic purposes. Thereafter, diagnostic functions are performed.

5. INIT. By pressing this key, a reset is triggered exclusively in the microcomputer assembly 2. Thereafter, there runs a special initialization routine, which also causes previously stored error records to be output.

6. PWR CHK RESET. This will clear fault indications of the power supply blocks.

7. INDIC TEST. This checks the functionality of all LEDs. , ^: ... ,

8. PLR CHECKS. These are the lights for power supply errors.

9. HDW CHECKS. These are the lights for "hard" errors in the microcomputer array 2 and. in the central control means 9 of the bus system. 1

10. PGM DETECTED CHECKS. These 7-segment displays are used by microcomputer array 2 programs to indicate fault situations and special conditions.

The elements of the control panel shown in Fig. 5 have the following function:

1. OFF LINE. This key is used to switch on or disconnect the operating and service processor from the standard interface 21.

2. DVC CHECK. This is the collective display for all error messages of the arrangement.

3. NOT CONNECTED. This Jsfc the display for the operability of the special interface 20 (the indicator lights up when the logical connection is not established).

4. CONNECT. This key switch is used to turn on or off with respect to the special interface 20.

5. MAINT ENABLE. This key switch is used to prevent the execution of special maintenance operations in the system to be operated. - · · · ·.

6 3 A 5

The not shown in Fig. 5 further elements of the control panel are used essentially for power on and off.

Fig. 6 shows the design of the keyboard 11. In addition to the usual and conventional keypads are "of importance:

- 6- "variable function tests". These have a respective image and situation-dependent meaning, which is explained in the 24th line of the screen monitor 7.

- CTRL key. This is used to trigger the image change on the screen just assigned. The respective desired image is identified by a subsequent character input.

- ESO button. This is used to switch the rest of the keyboard between the two screens.

Which screen is currently assigned is in the 24th line

of the monitor 7. .

The easy operability of the arrangement of the two screen monitors 6; 7 and the keyboard 11 is ensured by the compact arrangement of these modules in a complex (both monitors side by side, keyboard immediately before).

Fig. 7 shows details of the printer adapter 14. This is designed as a dual adapter, so that the printing unit 15 can be controlled by both the microcomputer assembly 2 and the microcomputer assembly 3. Essentially two registers with tri-state outputs are provided as selection circuits for the printing unit control signals.

The selection is controlled by the microcomputer array 2 via the SELECT line. This line is returned to the microcomputer array 3. This allows them to check whether the printing unit 15 is available for them.

Normally, the microcomputer assembly 3 uses the printing unit 15 for the usual output operations. The microcomputer assembly 2 uses the printing unit 15 only to output error messages. It can do this via the SELECT line.

The microcomputer assembly 3 is informed by the illustrated feedback about it.

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In Jig. 8, some details of the central control means 9 of the universal bus 1 in the context of the microcomputer arrangement 2 are shown »

The universal bus 1 has two lines HOLD; SELEGT, which are used to select the Mäster device in the respective bus cycle. These lines are connected to the corresponding flip-flops of the central control means 9 with the interposition of AND gates, which are connected downstream of a flip-flop 23 which is arranged so that it can be switched on and off programmatically by the microcomputer arrangement 2. Furthermore, the microcomputer arrangement may be effectively 2 itself as master to the universal bus'. For this purpose, a master request circuit 24 is present, which directly with the signals HOLD | SELECT from the central control means 9 is connected. The purpose of the flip-flop 23 is to enable the universal bus 1 either for general use (then become .alpha.) HOLD; SELECT active on the entire universal bus 1) or for exclusive use by the microcomputer array 2 (HOLD; SELECT are not given to the universal bus 1, but evaluated only by the master request circuit 24).

Thus, the microcomputer assembly 2 can perform as "hard core" test and maintenance functions for the entire operating and service processor. To output results while the screen monitor 7 and the printing unit 15 are available. Due to the direct connection of the printing unit 15, a detailed state output is still possible even if serious defects occur on the universal bus 1 or if the control means 5 have failed.

Thus, the arrangement of the invention allows a largely automated testing and error correction. The means provided allow a process to be carried out as follows:

1. An error occurs in the operator and service processor.

2. Thereupon, an interruption is triggered in the microcomputer arrangement 2.

3. This causes the start of a fault routine. This records the nearer error conditions in a recording block. The current recording block is 16 bytes long. Overall, the last 4 recording blocks are saved.

4. Thereafter, the microcomputer arrangement 2 via the flip-flop 23 switches the universal bus 1 to "exclusively internal use" UEU

5 · If the device is able to process more extensive error routines, this processing is started.

6. If the arrangement is not able to do so, all the recording blocks are output via the printing unit 15, and the currently current recording block is displayed on the screen monitor 7. Furthermore, appropriate warnings are displayed.

After that, in general, only a new initialization is meaningful.

Through this detailed error handling and display, maintenance personnel are generally able to locate and eliminate the error very quickly.

To test the device are COM-resident routines in the microcomputer assemblies 2; 3; 4 and other test routines on floppy disks, for the Yerfügung. To execute these test routines, one of the microcomputer arrays 3 '' 4 must be functional. Since two identical arrangements are present, this requirement is easily met in practice.

The arrangement according to the invention thus achieves high availability by always providing at least two alternative options for fast, largely automated troubleshooting so that the number of cases in which troubleshooting with elementary means (eg oscilloscopes) is unavoidable drastically reduced. There is no significant increase in effort (in contrast to the double structure of the entire device.

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Also, in contrast to double arrangements, a larger failure distance of the entire device is given, since only the minimum necessary number of components is used. Thus, a double or multiple installation of such devices is required only for extreme demands on the time availability (for example, in large real-time computer systems). The structure according to the invention furthermore permits the use of inexpensive microcomputer arrangements which in themselves do not seem to be suitable for such demanding tasks. This has a positive effect on manufacturing costs, warehousing and energy consumption (compared to other solutions on Basii special controllers or more powerful minicomputers).

The further advantages of the arrangement according to the invention can be summarized as follows:

- The screen displays can be made clear and meaningful, as it is possible. Due to the large display capacity to perform all representations in plain text or in easily understandable mnemonics.

- System messages can be put on two independent areas.

In particular, it is possible to present detailed information about the system to be operated and about internal states during normal operation (without image change).

- The internal maintenance and diagnostic functions are carried out using the keyboard, screen and printing unit, so that the ease of use for these punctures is practically close to that intended for the system to be operated. - -

- In case of failure of a screen monitor can be continued without significant downtime.

- The performance reduction when processing multiple concurrent requests is low.

Claims (2)

Invention claims: (1) are formed so that the lines for the master selection (HOLD; SELECT) of the universal bus (1) first to the master request circuit (24) of the microcomputer arrangement 1 · Operating and service processor, preferably for computer equipment, with a microprocessor, with a universal bus to which control means for a screen, an adapter for connection to the central unit (interface adapter) and a keyboard are connected characterized in that a second microcomputer arrangement (4) and an adapter arrangement (19) for controlling a special interface (20) and a third microcomputer arrangement (3) are connected to the universal bus that the keyboard (11), an acoustic Signaling device (10), and maintenance and control means (13) to the first microcomputer arrangement (2) are connected, that the control means (5) via an exchange circuit (22) two screen monitors (6; 7) are connected downstream a printing unit (15) with the interposition of a printer adapter (14) of both the first and the second microcomputer arrangement (2, 3) is arranged downstream and in that the central control means of the universal bus (1 ) are present in the first microcomputer array · 2 · Operating and service processor according to item 1, characterized in that the printer adapter (14) is designed such that the signals for the printing unit (15) are connected to selection circuits which are connected to the microcomputer arrangements (2; 3) that said selection circuits are preceded by a select line (SELECT) which is connected to the first microcomputer arrangement (2) and that this selection line (SELEGT) is fed back to the second microcomputer arrangement (3) on the input side. 3 «operating and service processor according to item 1, characterized in that the central control means (9) of the universal bus (2) and subsequently connected to conjunctive links with a flip-flop (23) connected to the microcomputer array (2). "