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AN HC11 FILE MANAGER

Part IıLaying the Foundation
by Walter Krawec

Start ı Tools ı Deciding What to do First ı Letıs Get to Work ı Compiling ı Running the Program ı How Will it Work? ı What's to Follow • Sources and PDF

HOW WILL IT WORK?

Before I go, Iıll give you a brief description of how the file manager is going to work. Letıs say that you have the 32-Kb RAM at 0x8000. The file manager will take no more than 0x8000 to 0x9000 (in fact less, but this is what youıll give to the file manager). Then at address 0x9000, the total number of programs will be listed. This will take two bytes.

At this point, the start and end addresses of the first program are defined. These addresses tell the file manager what address to jump to in order to run the program and where the program ends. Each of these takes two bytes.

Next comes the first programıs name and type. The name can be five characters long, and the type three characters long. It will be read as "*****.***". For example, you could have a program called test1, and because itıs a program, it will be called TEST1.PRG. You donıt have to use the extension .PRG for the program, you can use whatever you want (e.g., .EXE or .S19).

This continues until all of the programs have been defined. After the last one has been defined, the first program starts (the programs will start no sooner than address 0xA000).

A memory map of the file manager can be seen in Figure 1.

Figure 1ıThis is how the file manager uses the HC11ıs memory.

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