[comp.os.cpm] USART-8251 mode byte

prindle@nadc.arpa (02/26/87)

The mode byte bits are as follows:
	Bits 7-6:	Number of stop bits
		00: invalid
		01: 1 bit
		10: 1.5 bits
		11: 2 bits
	Bit 5:		Parity type
		0: odd
		1: even
	Bit 4:		Parity enable
		0: disable
		1: enable
	Bits 3-2:	Character length (not including parity bit)
		00: 5 bits
		01: 6 bits
		10: 7 bits
		11: 8 bits
	Bits 1-0:	Clock multiplier
		00: Sync mode
		01: 1X
		10: 16X
		11: 64X
Thus 07AH is the correct setting for Seven bits, even parity, one stop bit,
16X clock.  05AH is the same with odd parity.
Sincerely,
Frank Prindle
Prindle@NADC.arpa