
3.1 FLEX-ES 
This redbook concentrates on the use of 
The following descriptions and figures assume this particular ThinkPad/EFS configuration. Other configurations and more complex systems are possible, but are not described here.
3.1.1 Brief introduction
Conceptually, 
A S/390 instruction emulator, which might be seen as the heart of the system. It examines each S/390 operation code and emulates that operation, using the instructions of its underlying PC processor.
A resource manager that controls the interfaces between the emulated S/390 processors and emulated I/O devices and connections.
Emulators for various S/390 I/O devices.
A 
A Terminal Solicitor program that emulates local, 
A number of utility programs to help set up and run the 
Figure 3-1 provides a simplified view of FLEX-ES  operation. FLEX-ES  is simply a process1 under Linux. While this illustration should not be taken too literally, it can be used to make a number of basic points about FLEX-ES. 
1It is actually a number of interrelated processes and threads, but that can be ignored at the conceptual level.
16S/390 PID: ThinkPad Enabled for S/390