Another array was suggested, but shot down by OP, because it was too... memory consuming, I think.
Nevertheless, I think both ways should be tested and the one that performs the best picked.
Originally Posted by Adak
io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
Originally Posted by Salem
You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.
Outside of your DOS world, your header file is meaningless.