Chapter 1. System Kernel
1.System Kernel
This chapter is used to introduce the system kernel of MR350MKII. Where the system kernel is divided into six subsystems to service application programming interface, keyboard input, LCD display, communication I/O, Real Time Clock, Relay output/Digital input and Barcode wand/Magnetic stripe/Proximity reader.
1.1.Application Programming Interface
The MR350MKII kernel includes three basic modules: device driver, file manager and DOS manager. The programmer can design the application programs by calling those available functions just like that in the PC DOS environment.
The ROM based operating system of the terminal provides emulated MS/DOS function calls. The calling and parameter passing conventions are identical to that of MS/DOS. The detailed description of supported functions of the Terminal's subsystems, I/O interface, DOS manager and File manager is defined in later chapters.
The software to be run on MR350MKII may be programmed by using Microsoft C 5.1 and later version, and the IBM PC macro assembler version 1.0 and later version. Transaction data can be processed interactively with the computer or stored in a file.
NOTE in using Microsoft C:
When program execution area assigned less than 64K (see section 4.3) and a program with size more than 64K is invoked to run. A run time error message, "Not enough space for environment", will be shown. In this case add following statement in main:
/* mypgm.c */ _setenvp()
{
}
main() {...
...
...
}
and link with: >LINK /NOE mypgm
