比较详尽的VGA端口寄存器的文档，分类介绍了DOS下常用的VGA类型。在DOS下进行VGA编程必备。-A more detailed document VGA port registers, classification introduced commonly used VGA under DOS type. In DOS programming required under the VGA.

This is a compact satellite tracking program. Using it even an older PC (from 486 up, DOS, VGA) can serve to track a satellite and turn the antenna, which allows newer PCs to be used for other purposes. For example other software can be used in paral