Experience with porting techniques on a COBOL 74 compiler

The problems of compiler construction have largely been solved for COBOL '74, but a remaining fundamental consideration in a commercial environment is the cost of compiler development. This can be reduced by the use of portable software, but the cost of porting to a new system remains significant. In the microprocessor system market, two approaches have been followed. The first is to produce software for a virtual machine environment and simulate this on real hardware be means of an interpreter. Most software, including language processors and large parts of the operating system, can be transferred almost unchanged to a new processor. Nearly all commercial software for microprocessors has been developed on this basis. The alternative approach is to produce software which, by virtue of certain characteristics, can be made to be portable to new real machine environments, provided the appropriate high level language compiler is available.