JPS6046747B2 - Initial program loading method - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an initial program reading method in a computer (nothing is initially stored in order to start up the computer).
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There is a method of reading from a paper tape reader or other input/output device, and hereinafter referred to as IPL (InitialPr).
It is called the ogramIJ)ading) method.

) relates to a method for externally specifying an initial program reading program corresponding to an input/output device that is to perform IPL on a computer when performing IPL.
[Background of the Invention] Regarding the conventional IPL method, at least the following two are required when performing IPL as described below.

One of them is an address (this may be a logical address or a physical address) assigned to an input/output device that writes an initial program to the computer's main memory, and is hereinafter referred to as a device address. The other one is a program for reading an initial program from a target input/output device that performs IPL, and this generally differs depending on the input/output device. When performing IPL, at least the above two types of information must be entered into the computer.

Further, in conjunction with this, other processing may be instructed to be performed at the same time as IPL. This information is input into a computer as data, and the method is generally for an operator to input it from an operator's console or a device with equivalent functionality. The data described above will be referred to as IPL data.

IPL data will be explained with reference to FIG. An example in which one data word consists of 16 bits will now be explained. In this figure, bit 0 is a bit for causing the computer to perform some processing at the same time as IPL, and is named a control bit because of the processing content. Bit 1,
Reference numeral 2 is a specific bit that indicates the address of the storage device where the start address of the program for reading the initial program from the input/output device that performs IPL is stored. A program for initial program reading is read into the computer from the address indicated by the start address. The remaining bits among the 16 bits indicate the device address of the input/output device to be subjected to IPL.

These bit configurations vary depending on the data format determined by the computer. The storage device that stores the IPL program corresponding to the input/output device is a read-only memory (R
OM), the contents of the storage device are immutable. In such a conventional IPL method, the device correspondence 1 in the storage device is directly determined from specific bits (bits 1 and 2) of the IPL data.
There is a problem in that the number of IPL programs that can be specified in order to specify the start address of a PL program is limited.

That is, in the example shown in FIG. 1, since the specific bits specifying the start address are 2 bits, the start address designation table of the device-compatible 1PL program can accommodate only 4 words. This is a problem that cannot be ignored in view of the current situation where the input/output devices constituting the computer systems are also diversifying due to the diversification of computer systems.

In general, the initial programs for multiple input/output devices in a computer system differ when the computer is started up (for example, differences in startup processing depending on the startup factors, such as startup by the operator, startup when power is restored, etc.) It depends. Therefore, it is an important factor to improve the flexibility of computer system construction to be able to arbitrarily set some initial programs in a computer in advance from among as many types of initial programs as possible. [Object of the Invention] The present invention has been made in view of the problems of the prior art.
When specifying an IPL program inside a storage device in which a PL program is stored, the purpose is to expand the number of device-compatible 1 PL programs that can be specified while keeping specific bits on IPL data fixed.

[Summary of the invention]

The feature of the present invention is that instead of directly specifying the start address of a device-compatible 1PL program from a specific bit of IPL data, at least one address specification switch with a multi-bit configuration is provided to indirectly specify the start address of the device-compatible 1PL program. This is the point.

One of the address setting switches is selected by a specific bit of the IPL data, and the bit set on the address setting switch specifies the start address of the storage device in which the IPL program is stored. Programs can be specified. [Embodiment of the Invention] An embodiment of the present invention is shown in FIG.

This figure shows an example in which an address setting switch is provided to indirectly specify the start address of a device-compatible 1PL program.
With a bit configuration, a 16-word start address specification table for a device-compatible 1PL program can be created with just one switch, compared to the conventional example shown in Figure 1, which can only specify 4 words. Can be expanded significantly. In this case, the IPL specific data is fixed, and the operator arbitrarily sets the 4 bits of the address setting switch using a console or the like. On the other hand, providing four switches with a 4-bit configuration as shown in FIG. 2 has a different meaning.

Four of the start addresses of any IPL program used in the computer system can be preset for each switch, and the operator only needs to specify specific bits of the IPL from the programmer's console, etc. when starting up the computer. This is because one of the four arbitrary IPL programs set in advance can be specified. In other words, if the IPL program to be used is set in advance according to the computer system, the operator only needs to specify a specific bit of the IPL at startup, just as in conventional operations, and operator errors can be prevented. . Note that the bit number and number of addressing switches may be determined depending on the type of input/output device of the target system, and can be expanded to any number.

〔Effect of the invention〕

According to the present invention, by providing an address designation switch and indirectly designating the start address of IPL data, it is possible to designate a larger number of IPL programs than can be directly designated by specific bits on the IPL data. It becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional example of designating the start address of a storage device that stores a program for initial program reading, and FIG. 2 is a diagram showing an embodiment of the present invention using an addressing switch. IPL: Initial program reading method.

Claims (1)

[Claims] 1. A memory that stores a program for reading an initial program corresponding to a plurality of input/output devices provided outside the computer in order to read the initial program for starting up the computer into the main storage device from the plurality of input/output devices. has a device;
Specify the start address of the initial program reading program corresponding to multiple input/output devices in the storage device using a specific bit of the data for initial program reading that can be set externally, and read the corresponding initial program reading. In an initial program reading method in which a computer reads a program, at least one addressing switch having a plurality of bits is provided for specifying the start address, one of the addressing switches is selected by the specific bit, and the selection is made. By externally setting a plurality of bits in the address designation switch, the start address is indirectly specified from the specific bit, and one of the plurality of programs for initial program reading is specified. Initial program loading method.