CMOS(Complementary Metal-Oxide-Semiconductor) A type of integrated circuit design known for its low power consumption. 0Bh - RTCsee Real-Time Clock - STATUS REGISTER B (read/write) 


Bitfields for Real-Time ClockA battery-powered clock which continues to maintain its time even while the system is powered down.  On PCs, the real-time clock contains a small amount of battery-powered memory (set CMOS RAM). status register B:
Bit(s)	Description	(Table C0002)
 7	enable clock setting by freezing updates
 6	enable periodic interrupt
 5	enable alarm interrupt
 4	enable update-ended interrupt
 3	enable square wave output
 2	Data Mode - 0: BCD(Binary Coded Decimal) A method of data storage where two decimal digits are stored in each byte, one in the upper four bits and the other in the lower four bits.  Since only the values 0 through 9 are used in each half of a byte, BCD values can be read as decimal numbers on a hexadecimal display of memory or a file., 1: Binary
 1	24/12 hour selection - 1 enables 24 hour mode
 0	Daylight Savings Enable
	=1 enables automatic switching to/from DST in April and October
Notes:	some operating systems seem to change the CMOS(Complementary Metal-Oxide-Semiconductor) A type of integrated circuit design known for its low power consumption. clock rate to slower
	  values for unknown purposes. Since on older ATs the clock rate does
	  not get restored after a cold boot, this may slow down disk
	  operations for example under PCIBM PC DOS which depends on the clock rate.
	If IBMBIO.COM finds a model byte FCh (sub-models 00h, 01h, 02h, 03h,
	  or 06h) during init, it resets the clock rate to the default value
	  (00100110b).
SeeAlso: #C0001,#C0003,#C0004