Published March 2000

EMBED THIS PC

PART 3: Emulator to the App Test
by George Martin

Start • The Program • Real Mode • Getting An App Up and Running • Sources and PDF

GETTING AN APP UP AND RUNNING

At present, Paradigm only works in 16-bit real mode, although I noticed some 32-bit register optimizations and understand it is releasing a 32-bit protected-mode version.

To create a project in the Paradigm environment, use the Paradigm project wizard software to generate a set of startup modules and a dummy main module. You can add your application code to the module set. Be sure to tell the linker which libraries to use and the locator where to place all the code.

While you debug the code and have PDREMOTE running, you need to map differently than for the final production version. The PDREMOTE code currently resides at F000:0000 as a full 64-KB segment, although it is much smaller. I moved the application to D000:0000, which is another free segment in the BIOS flash memory.

You also must defeat the setting of the CPU configuration registers in and out application. PDREMOTE is running and already did that setup. You can insert a jump in the assembly language startup module to bypass the register setting. You might consider that an ugly approach, but beauty is in the eye of the beholder. Perhaps a define or conditional compile (assemble) flag would be more elegant.

Actually, I created a directory in the working project directory, which I named EPROM. All the code is the same in the two directories, except for changes I’m discussing. I can edit and debug code in the debug directory. Then, when I want to make an EPROM, I can copy all the C and H files to the EPROM directory and compile. By using this method, a file-compare program can contrast the two sets of files and find the minor differences created during debugging.

WHAT’S NEXT

So, now I have an emulator, a simple design of a 486 using AMD SC400, startup code for the emulator, and a project. Next month, I’ll take a look at some of the details of the SC400 and the addition of the D/A converters.

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