↑ Bose, Sanjay K. (2007). Hardware And Software Of Personal Computers. New Age International. p. 54. ISBN 9788122403039. Retrieved 2012-09-10. "Once the INS 8250 has been properly initialized, we should make proper use of the Modem Status register (MSR), Line Status register (LSR) and the Interrupt Identification register (IIR) for controlling the device during actual operation."
↑ Microsoft MVP: If every hardware engineer just understood that... …write-only registers make debugging almost impossible
↑ Microsoft "Guidelines for Bus and Device Specifications"
