slang@waikato.ac.nz (02/13/91)
I need to find out exactly how to program the CMOS RAM on a Chips & Tech 386sx motherboard, as well as what locations are already in use so they can be avoided. I beleive that many chipsets store memory configuration in there, as well as hard disk/floppy disk drive types. From what I have found out so far, an output to port 70h selects what CMOS memory location is selected, and then an input from port 71h reads it, or output to 71h writes it. All I need is a couple (2) of free bytes in CMOS to store a serial number. Also, I think that some PC's may have there CMOS RAM checksummed, to detect low battery or tampering. Steve Lang Systams Programmer Analyst University of Waikato Hamilton NEW ZEALAND slang@waikato.ac.nz