lee@Utexas-11@sri-unix (09/16/82)
From: Bill Lee <lee@Utexas-11> What you need is a Motorola microcomputer components guide. It will tell you everything you need to know about the 6850 as well as other Motorola components that you may be using. 03H is Master Reset. 8 bit/no parity/ 1 stop bit is 14H. 8 bits/even parity/1 stop bit is 018H. Odd parity is 01CH (these are bits 2, 3, and 4). Bits 5 and 6 are Transmitter Control Bits which control transmitter interrupts depending on RTS. The high bit (bit 7) is Receive Interrupt Enable. And finally, the bottom 2 bits are Counter Divide Select. 01H is divide by 16. What you were sending with 91H was Receive Interrupt Enable, RTS=low, transmittinginterrupt disabled, 8 bits plus 2 stop bits, and divide the clock by 16. What you may want to be putting in the control register is 15H. As you can see this gets very complicated and you should probably have a data sheet to see what you are doing. -------