PrintStar's Blog
Ramblings of a Fortran Nut
September 11, 2008 by Jeff

Still Here… And Working with the Rainbow

Things have been busy since the end of RetroChallenge 2008. Almost immediately following the competition my presence was necessary in Massachusetts (about 600 miles from Cleveland) for my sister’s wedding. Also, Approximatrix has released Draco R1.1, which consumed most of my free time. The Rainbow remains set up next to my Debian desktop, however; I try to connect to the RetroBBS through it once a day for the nostalgia feeling.

I’ve had a bit of additional time to work on the Rainbow. Fellow RC’er equant inspired me during the contest to port robotfindskitten to the Rainbow. The game is text-based, and the source code is exceptionally brief and easy to understand. The game itself may be the “silliest” I’ve ever played.

The big problem porting it to the Rainbow is the cursor positioning. The original source was written in Turbo C++ using its console operations. The Rainbow, of course, is not compatible with IBM PC console operations, so they needed to be rewritten. Specifically, rfk uses putchar(x,y,c) calls to position ASCII characters on the screen. An equivalent is necessary on the ‘bow, but had proven to be elusive. I had previously attempted to used erroneous assembly routines and VT52 escape sequences to position characters. I finally cracked the interrupt routines, however. The Rainbow places all console operations on interrupt 0×18, but the documentation is somewhat sparse.

Now that I have the positioning working, I think I might be able to get rfk up and running on my favorite platform.

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