How can I customize the switch settings on my LaserWriter Pro 630, and what does this actually do?

The LaserWriter Utility allows you to customize switch positions 6 thru 9; thereafter, whenever you change the physical switch positions located on the printer itself to 6 thru 9, the printer's communication ports incorporate whatever communication parameters you gave them with the utility. What may be confusing is the LaserWriter Utility doesn't allow you to override the physical switch settings on the printer, only configure 6 thru 9.

If the Current Printer Switch Settings returned by the LaserWriter Utility (Utilities menu: Configure Communications) is different then the actual physical switch position you've set on the printer, then you may have a hardware problem.