1.1 Layers of Computer System

 

Each level performs a related subset of function

and each level relies on next lower level to perform more primitive functions.

每个层次执行相关的功能子集，每个层次依赖下一低层执行更原始的功能。

 

 Each layer (from M2 to M5) is a virtual machine.

M2到M5是虚拟机

In present-day computers all the instructions available at the conventional machine level(arithmetic, boolean,etc)

are carried out by a program running at the microprogramming level.

在传统机上的指令（算数、逻辑等）由微程序级的程序实现。

boolean即布尔

microprogramming

 

This program, which acts as an interpreter, unserstands a small set of very simple operations, calles the Micro（1） Instruction Set.

该程序是作为一个解释器，能理解一组简单的操作集合，称为微指令集。

（1）讲义上是Macro，意为巨大的，但ppt上是微指令集，我认为这里是Micro

The microprogram is supplied in ROM by manufacturer.

微程序由制造商以ROM形式提供

Thus nobody can program it but the manufacturer.