| 摘要 |
PURPOSE:To change easily a program, by constituting the following address field storage part of a control and storage medium, the whole field storage part of a microinstruction, and a part of the control storage area extending over the whole field of the microinstruction, of an RAM, and constituting other parts of an ROM. CONSTITUTION:A main part of a control storage body 1 of a computer using a microprogram system is constituted of an ROM, and the following address field storage part NA 5 and a part of a control storage area (part indicated by oblique lines) extending over the whole field of a microinstruction are constituted of an RAM. When changing a microprogram, the following address field NA of the microinstruction concerned is rewritten. When a new instruction is required, the new instruction is written in the control storage area whose whole field is constituted of the RAM. In this way, the microprogram is changed easily, and also the ROM which is profitable in its cost, heating, space, etc. can be used effectively for a control and storage device. |
