7526 DCT Reference
In most respects, a C language program for the 7526 is like a program
written for a personal computer.
The specific interfaces, devices, available storage, and
performance requirements are different from a PC, but the concepts and
common programming strategies for applications remain the same. While
there is no direct equivalent for PC-DOS in the 7526, the 7526 ROM
microcode combines low-level device control functions with several
high-level PC-DOS-like functions. Other differences between PC
programs and 7526 application programs exist because of the unique
elements of the 7526 programming environment, including:
- Battery backed-up RAM
- Watchdog timer
- Support for special devices, including bar code and magnetic
readers, DI/DO, a printer port, and a network port
- Absence of disk drives, math coprocessor, and so forth
- Substitute interfaces for other I/O such as the keypad and display.
Programs for the 7526 are developed on personal computers, using
a few specific compile and link options, and certain special files for
linking which handle the differences between the startup of a
EXE file on a personal computer and a 7526. The following programs are
required on the development personal computer:
- The "C" language programming tools from the
7526 CFR Programming Support Diskette included with this manual
- IBM C/2 Version 1.1
- IBM Macro Assembler/2 Version 1.0 or above (optional; cannot be used
for direct interface to CFR Application Program Interface routines,
but could be used for modules within the program)
- IBM DOS 3.3 or above, or IBM OS/2* with C/2 libraries selected to
create DOS applications.
The following special procedures or requirements must be followed:
- DOS-specific function calls may not be used (for example, DOS versions
of calls which use input or output functions specific to the IBM Personal
Computer or
Personal System/2*, including keyboard, display, printer, fixed disk, and
diskette drives.
C/2 functions such as "printf" and "sprintf" should not be used
because they bring in DOS-specific functions).
- Link with the special CRT0 "C" runtime modules, which allow programs
developed on a personal computer to be run on a 7526.
Note:
These programs will not run on a personal computer.
.