7 Chapter 2 Getting Started Summary; This chapter contains a general discussion of the assembly language sys- tem. A format for the creation of an assembly language program is presented. Topics such as modules, routines, and memory allocation are discussed, along with methods of using them effectively. Also discussed is the storage and retrieval of modules on mass storage. The thing to remember about the assembly language system is that it has been thoroughly integrated into the operating system of the 9835A/ B. Once the ROMs have been installed, you are able immediately to begin programming in assembly language.
In addition, you have the capability to load and store your programs on mass storage, to assemble them separately or and to debug them, including a full pausing and stepping capability. leave them in source form, to execute them from BASIC and pass BASIC variables to them, Developing Routines for Later Use Most assembly language programs are written with the intent that they will be used many times, not just at the time they are written. It is for just such program development that the full capabilities of the assembly language system come into play. The development comes in several stages. Each stage has its unique requirements and the tools to meet those require- ments.
The first stage is creation of the source program. This is achieved by the use of the editing capabilities of the 9835A/B. Additionally, the basic mass storage capabilities of the computer can be used. The second stage is the creation of the object (or machine) code. This requires not only an assembly of the source, but the ability to allocate special locations in memory to hold the newly created object code. The third stage is the validation of the routines as written, commonly known as "debugging". This is enabled by calls from a BASIC driver, followed by application of various debugging tools provided by the assembly system.
The capabilities to pause and step a program have been extended to assembly language instructions to assist this process.